- Email: [email protected]
Management of common minor discomforts in pregnancy
MANAGEMENT OF COMMON MINOR DISCOMFORTS IN PREGNANCY Part III: Managing Gastrointestinal Problems in Pregnancy
Mary C. Brucker, CNM
ABSTRACT The minor discomforts of pregnancy present difficulties for the health care provider as well as for the pregnant woman herself. Management of the various symptoms requires astute observations and the ability to individualize therapy. Knowledge of a variety of treatment options, therefore, allows practitioners to collaborate with their patients in selecting the best therapeutic approach for the specific situation. This three part series reviews the common discomforts associated with upper respiratory infections, minor pain, and gastrointestinal problems as they are manifested during pregnancy. Both nonpharmaceutical and pharmaceutical therapies are discussed. Frequent references are made to the Food and Drug Administration (FDA) Risk Factors which categorize both over-the-counter and prescribed drugs according to their documented safety for ingestion during pregnancy. Part I, “Managing Upper Respiratory Infections in Pregnancy”, appeared in JNM 32:6; Part II, “Managing Minor Pain in Pregnancy”, appeared in JNM 33:l; and Part III, “Managing Gastrointestinal Problems in Pregnancy”, appears in this issue.
Pregnancy affects all of the body’s organ systems to some extent. In this, the last of a three part series on management of common problems in the prenatal period, a system markedly affected by pregnancy is discussed. The affected system is the gastrointestinal tract. Clinical and mechanical changes serve to effect a wide diversity of symptomatology. Common minor discomforts frequently range from heartburn to constipation. Treatment of these complaints are based on the etiologic agent involved, as well as recognition of potential side effects, hazards, and teratogenicity of interventions.
Address correspondence to: Mary C. Btucker, CNM, 9600 Golf Lakes Trail #1004, Dallas, TX 75231. Journal of Nurse-Midwifery
??Vol.
MORNING SICKNESS
Although a single etiologic agent remains unproven, several theories about nausea and vomiting in pregnancy have been proposed. A major commonality of the theories has been the hormonal changes accompanying pregnancy. These hormonal changes include high levels of circulating steroids (e.g., estrogen), and high levels of human chorionic gonadotropin (HCG). It has been proposed that these agents have the ability to directly stimulate the chemoreceptor cells in the postrema of the medulla that are associated with vomiting.’ Other suggested factors have included slowed peristalsis of the gastrointestinal tract, and pressure from the enlarging uterus.2,3 The major treatments of nausea and vomiting in pregnancy are cur-
33, No. 2, March/April 1988
Copyright 0 1988 by the American College of Nurse-Midwives
rently nonpharmaceutical in nature. Small frequent meals, dry crackers upon arising to minimize the emptiness of the stomach, avoidance of strong odors, spicy foods, and very cold liquids are all common instructions. Other suggestions have included ingestion of foods that are sweet before retiring at night, or upon arising; restriction of fats in the diet; as well as separation of fluids from solids. Regardless of the popularity of these treatments, little scientific evidence appears to support their efficacy.l Hockenberry & Cotanch* suggested hypnotic suggestions in their work with nausea in children.* Reassurance is the single most universal, and possibly most effective remedy for the average case of mild morning sickness, as the condition normally dissipates by sixteen weeks of pregnancy.5s6 67 0091-2182/88/$!l3.50
However, there are instances in which the nonpharmaceutical approaches are inadequate. To initiate a pharmaceutical agent in the treatment of nausea and vomiting, the practitioner must consider several factors. These factors include patient desire, severity of the complaint, and reaction to the nonpharmaceutical interventions. The severity of the complaint can be assessed by patient report of interference with activities of normal living including work, or such objective signs as weight loss or urinary ketosis. Until recently, a popular medication for morning sickness was a combination of an antihistamine (doxyiamine succinate) and a vitamin formulation (pyridoxine), sold under the brand name of Bendectin. Although FDA investigation did not demonstrate teratogenic effects of this combination, litigation compelled the manufacturer to remove it from the marketplace.7 It should be noted that the same therapy is still available today by combining the exact same ingredients that are now sold in over-the-counter formulations. However, for the certified nurse-midwife to advise a patient to combine and use these medications is to assume a risk, apparently not of teratogenicity, but of liability. Other nonprescriptive drugs are available as antiemetics. The most common examples exist under the brand names of Emetrol, Especol and Controflex. They are all combinations of sugars (levulose [fructose], sucrose and dextrose) with phos-
Ms. Bruclcer received her Bachelor and Masters’degrees in nursing at St. Louis University. She obtained a certificate in nurse-midwifey from the Univekty of Mississippi. She has practiced nursemidwifery in public and private sectors. She is also a member of the Continuing Education faculty of the American College of Nurse-Midwives (ACNM) for the course on Maternal Fetal Pharmacology.
68
phoric acid added to control the pH. Although their efficacy as treatment for morning sickness has never been demonstrated, they continue to be marketed.879 There is no indication that they would be of harm in pregnancy unless the gravid woman were also diabetic. For the patients who need a pharmaceutical intervention for morning sickness, several options are available. Nausea and vomiting is usually most apparent in the first trimester. Thus, pharmaceutical interventions occur within the most teratogenic period for humans. However, for the women for whom nausea and vomiting pose a risk either to nutrition, as evidenced by significant weight loss, or to ability to conduct a normal life style, judicious use of an antiemetic may prove to break the cycle and prevent more serious consequences. Thus, use could allow her not only to resume activities of daily living, but also potentially allow better nourishment of the intrauterine conceptus who is also being affected. Antiemetics should be carefully evaluated before use in pregnancy. Buclizine is marketed under the name of Bucladin-S. Cyclizine can be purchased as Marezine. Mecliiine is commonly found as Antioerf or Bonine. All three of these pharmaceutical agents are used for motion sickness or nausea and vomiting. They are not commonly used in first trimester of pregnancy as all three have demonstrated some teratogenicity in rats specific to the early part of gestation. Buclizine, cyclizine, and mecliine all function by decreasing labyrinthine functions and may be involved with inhibition of the medullay chemoreceptor zone. Use for women who are breastfeeding should be on an individual basis as the drugs have been found in breast milk although the significance is unknown. Moreover, they may inhibit lactation itself. Scopolamine is a drug that was well established in obstetrics a few
decades ago. It was used intrapartally as an amnesiac in conjunction with analgesics to effect a condition termed “twilight sleep”. Scopolamine is still available, and commonly used as an antiemetic. In fact, it is often administered transdermally through skin patches. Scopolamine is a drug that relaxes smooth gastrointestinal muscles, inhibits the labyrinthine receptors, and decreases conduction in the vestibular cerebellar pathway. There are no indications that scopolamine has any effect on increasing blood pressure or respiration rate. The FDA risk factor rating for scopolamine is category C as no human or animal studies have been undertaken (Appendix A). For use when breastfeeding, there are no specific known neonatal implications. However, the drug is excreted in the breast milk and it has been associated with inhibition of lactation. Promethazine is commonly marketed as Phenergan. This agent is both an antihistamine and a phenothiazine derivative. The theorized method of action to quell nausea and vomiting is inhibition of the chemoreceptor zone in the medulla. A common side effect is drowsiness. There have been no reported teratogenie complications with promethazine. However, the drug is contraindicated in late third trimester. Women who ingest the medication at that time have a risk of increased jaundice for the neonate. This phenomenon is suggested to be related to neonatal deficiency in the ability to detoxify enzymes8s well as insufficient renal enzymes7 Promethazine is excreted in breast milk and theoretically may decrease lactation, as with most antihistamines. Usual dosage is an initial administration of 25 mg, then 12.5-25 mg every four to six hours. Two phenothiazines are of particular assistance in severe nausea and vomiting. These are chlorpromazine and prochlorperazine. The first is marketed as Thorazine, and the latter as Compazine. Thorazine may
Journal of Nurse-Midwifery
??Vol.
33, No. 2, March/April
1988
have a strong connotation being only a psychotropic drug for some care providers. However, Thorazine is a potent major antiemetic. For nausea and vomiting, it is used in a short course, at a lower dosage than for long term psychiatric use. Both phenothiazines inhibit the medullary chemoreceptor zone and are potent antiemetics. Although no studies have indicated first trimester teratogenie effects, the agents are not recommended in late pregnancy for risk of neonatal jaundice. During lactation, small amounts are excreted and they may actually enhance lactation by increasing prolactin secretions. Chlorpromazine and prochlorperazine have a common side effect of drowsiness. For the nauseated woman, the preferred method of administration is either rectal or parenteral. The parenteral dosage may range from 10 to 50 mg b.i.d. up to every four hours. Rectal suppositories of chlorpromazine are administered 50-100 mg three to four times daily. Suppositories for prochlorperazine are usually given 25 mg b.i.d. Unusual side effects have been reported to include muscle spasms, especially of the face; blurred vision; and dyskinesia. 7 HEARTBURN
Another common discomfort of pregnancy associated with gastrointestinal changes is heartburn. In this condition, gastric acids are refluxed or regurgitated into the lower esophagus by reversed peristalsis. The causes of the increased frequency of this condition in pregnancy have included: the effect of progesterone on the cardiac sphincter in the stomach, allowing it to relax; progesterone induced smooth muscle relaxation encouraging decreased gastrointestinal motility; and displacement and compression of the stomach by the enlarging uterus. Nonpharmaceutical interventions for a woman experiencing heartburn are similar to those for a woman with morning sickness.
Journal of Nurse-Midwifery
??
Small frequent meals, separation of fluids from solids, avoidance of fatty, spicy foods, and very cold liquids are common advice.2J0 Additionally, suggestions for straight posture and avoidance of a reclining position for one hour after eating also advocate increasing the functional room for the stomach and decreasing mechanical reasons that encourage heartburn3 The use of milk is quite controversial as it has been reported to be a gastric irritant.* Other ingestible items that can potentiate gastrointestinal irritation and should be limited include smoking, alcohol, coffee, and chocolate. The first two are implicated in other risks in pregnancy. When such advice is not sufficient, the certified nurse-midwife must evaluate whether a pharmaceutical intervention is warranted. Again, the factors will include patient desire and report of severity of the condition. Severe fatigue may also be reported because of interference with sleep. Weight loss may indicate a need for further interventions. When the decision has been made to introduce a pharmaceutical agent, the medication of choice is an antacid. Antacids ideally should have the capability to not only neutralize acid, but be composed of both magnesium and aluminum. Magnesium alone tends to cause diarrhea; whereas aluminum alone is associated with constipation. Calcium has rapid onset and is able to neutralize well, but a condition of rebound hyperacidity is often associated with it. Turns (calcium carTherefore, bonate) may not be a first choice as an antacid, although for nonpregnant women, it is an easily accessible method of obtaining bioavailable calcium to aid in reducing the risks of osteoporosis. In general, the liquid formulations of antacids are more acid neutralizing than tablet form, although not always as convenient. Phosphates are usually slightly less effective than carbonates, hydroxides, or oxides. Simethicone is yet another pharma-
Vol. 33, No. 2, March/April 1988
ceutical agent that is commonly found in antacids. In vitro studies have demonstrated a decrease in surface tension of gas bubbles. Thus, it is proposed to decrease gas for patients using it. However, no clinical studies have firmly established this fact. 7 Because sodium has no therapeutic value for treatment of heartbum, it is advisable to recommend antacids that are low in sodium. Thus, sodium bicarbonate, citral carbonate, or the over-the-counter Alka Seltzer are not to be prescribed because of high sodium levels. Even one of the most commonly prescribed antacid combinations, alumina, magnesium, and simethicone (e.g., Amphojel Plus, Di-Gel, Maalox Plus, Mylar&a-11) can have varying amounts of sodium. The low sodium antacids include magaldrate and magaldrate and simethicone. Appendix B summarizes the content of commonly available antacids. There are no well controlled studies of the use of antacids in pregnancy. However, the studies that have been completed do not associate these pharmaceutical agents with increased congenital anomalies. Chronic use of any of the major components of antacids are associated with potentially major side effects. For example, chronic use of aluminum agents is associated with increased deep tendon reflexes and possibly hypercalcemia; magnesium is associated with decreased muscle tone, and cardiovascular and respiratoy impairment; and calcium with decreased deep tendon reflexes and increased muscle tone. Although aluminum, calcium, simethicone, and magnesium are found in breast milk, the concentration is low. Moreover, there have been no reports of neonatal effects. Because antacids coat the gastrointestinal tract, other agents may be malabsorbed. Among these agents are anticoagulants, salicylates, and vitamin E. Diagnostic tests for serum phosphate, potassium, and calcium
69
levels can all be incorrect if antacids have been used frequently. The general dosages for tablet use are one to eight tablets, chewed thoroughly in divided doses over three to four times daily between meals and at bedtime. When using the liquid form, 5-30 cc are usually prescribed. This varies upon the product and each agent should be scrutinized for recommended dosage.
CONSTIPATION
An annoying minor discomfort of pregnancy is constipation. As with heartburn, one of the most common theories as to its etiology includes the muscular relaxation associated with progesterone as well as mechanical compression and displacement of the bowel by the enlarging uterus. Iron supplementation also may cause constipation. Nonpharmaceutical measures include increased fluids, warm liquids upon arising, bulk and fiber foods in the diet, exercise, and establishment of regular good bowel habits.12J3J4 The major reasons for initiation of a pharmaceutical remedy for constipation include patient desire and inadequacy of the nonpharmaceutical measures. Occasionally constipation will be so severe that pharmaceutical interventions will be started and then the nonpharmaceutical remedies will be used prophylactically to prevent a recurrence. There are five different categories of laxatives available. Most of these can be obtained overthe-counter. All laxatives should be used judiciously, as over-usage can lead to dependancy. Moreover, as laxatives either increase GI emptying time or coat the tract with emollients or gels, food and medications taken at approximately the same time will have diminished effects. In general, the best agents for prophylaxis are bulk, lubricants, and emollients. The best intervention for treatment would be bulk, and rare use of stimulants.
70
In pregnancy, bulk laxatives and emollients appear to have the least potential side effects. The first category is bulk forming laxatives. These absorb water and actually swell in the gastrointestinal system. Bulk laxatives are best used as an initial type of treatment, and should be administered with a full glass of water. Usual time for onset is 12 to 24 hours after administration. Bulk forming laxatives include methylcellulose, psyllium hydrophilic mucilloid, malt soup extract, polycarboPhil, and psyllium. Emollients comprise the second category of laxatives. They are particularly advisable if a hard mass is present. Emollients reduce the surface tension of the liquid contents of the bowel so more fluid goes into the stool itself. Another point of consideration, especially for the patient with hemorrhoids, is that facilitating the passage of stool also can decrease the associated straining. Examples of emollients are docusate and poloxamer 188. These agents usually act after 24 to 48 hours. Emollients potentiate any other laxative. This should be considered if a combination approach is sought. Hyperosmotics are usually subdivided into lactulose or saline. Lactulose hyperosmotics cause an increase in osmolar tension that causes an increase in fluid accumulation, distention, peristalsis, and evacuation Saline hyperosmotics are similar although by using saline they are able to draw water into the lumen that causes the above fluid accumulation. It is also proposed that saline hyperosmotics use the release of cholecystokinin to enhance the laxative effect. Lactulose is an example of hyperosmotics; as are magnesium citrate, magnesium sulfate, and sodium phosphate. Lactulose is effective 24 to 48 hours after administration. The saline hyperosmotics have the shortest peak time, of 30 minutes to three hours. Thus, they are not advisable to be administered before bedtime and they also can promote
sodium retention with edema resulting in pregnancy. Lubricants are similar to emollients, and actually are no more or less effective than those. These agents coat the stools and the intestines with a water immiscible film. Thus, there is an increased accumulation of water in the stool itself. These are usually effective six to eight hours after administration. A traditional lubricant is mineral oil. Mineral oil often is not recommended in pregnancy for constipation because long term use of the medication can interfere with absorption of fat soluble vitamins. Stimulants are yet another category of laxatives and are rarely needed in pregnancy. They tend to cause cramping as they actually stimulate the GI system. This in turn causes additional patient discomfort. The exact mechanism of action is unknown although it is theorized that the intramural nerve plexis is irritated. The USPDI suggested that such stimulants as castor oil are contraindicated for treatment of constipation, as “its use often results in pelvic area engorement which may initiate reflex stimulation of the gravid uterus.“7 Examples of stimulants used to treat constipation are: castor oil, cascara sagrada, bisacodyl, danthron, dehydrocholic acid, phenolphthalein, senna, sennosides. Appendix C lists generic and brand names of laxatives. There are no current teratogenic links with the use of laxatives in pregnancy. Few studies have been conducted in the area. For breastfeeding mothers, cascara sagrada and danthron have each had reported cases of loose stools in the infants. When using laxatives, there are drug interactions with diuretics (decreased serum potassium) and anticoagulants (decreased effect due to physical binding). Salicylates are particularly affected by bulk forming agents. These agents decrease the effectiveness of the salicylates.
Journal of Nurse-Midwifery
??Vol.
33, No. 2, March/April 1988
Chronic use of emollients with danthron have been associated with liver damage. All laxatives are contraindicated in the presence of appendicitis, rectal bleeding, congestive heart failure, fecal impaction, and intestinal obstruction. Laxatives may also contain high levels of sugar as well as sodium. Psyllium has had up to 50% dextrose and effervescent laxatives may have up to 250 mg of sodium. The common dosage for laxatives is one to three tablets at bedtime or for one dosage. Liquid dosage depends on the pharmaceutical agent involved and usually ranges from 5 to 60 cc. DIARRHEA
Diarrhea is not usually listed as a common minor discomfort of pregnancy, but in practice it commonly exists. Often it is of a food origin. Occasionally it is a side effect of an influenza viral disease. Although a pregnant woman is not at increased risk for diarrhea when compared with her nonpregnant counterpart, she may be at increased risk for influenza if she is already a mother. Being a mother increases her proximity to a variety of illnesses from her offspring. Thus, it is not unlikely that the certified nurse-midwife will be faced with a patient complaining of diarrhea in pregnancy. Diarrhea is a situation in which nonpharmaceutical agents are clearly the interventions of choice. The acute short term diarrhea is best treated with tincture of time. Whether it be due to infection or maldigestion, it is usually a self limiting crisis, Common etiologic agents may include E. coli, Staphylococci, or Salmonella. The basic supportive therapy is fluid replacement. High fiber foods should be avoided. Thus, such foods as unrefined cereals, fruits, and vegetables are to be limited, as well as lactose containing foods. The side effects of an episode of
Journal of Nurse-Midwifery
??
diarrhea may range from minor patient discomfort to perianal irritation, hemorrhoidal irritation, dehydration, and hypokalemia. Dehydration is of particular concern in pregnancy with its association with preterm labor. Thus, replacement fluid should be sought with vigor to prevent this complication. Rarely, diarrhea does not respond itself to palliative treatment in 24 to 48 hours. In those cases a diagnosis of a more severe gastrointestinal condition as inflammatory bowel syndrome should be entertained. Introduction of an antidiarrheal pharmaceutical agent depends upon such factors as duration and severity of the condition, patient desire, and risk of dehydration among others. The basic types of antidiarrheals include opiates and adsorbants. Opiates slow the gastrointestinal motility and prolong transit time. This is accomplished by interactions with the central opiate receptors. A purified opioid such as codeine is as effective as an antidiarrheal agent as a camphorated opium tincture (Paregoric). Opiates are slightly more effective than their pharmaceutically related compounds of diphenoxylate with atropine (Lomotil) or difenoxin and atropine (Motofen). Codeine sulfate or phosphate can be administered as an antidian-heal at a dose of 15-60 mg every 4 to 8 hours. Opium tincture (Paregoric) is usually 5-10 mg up to four times daily. Opiates pass the placental barrier. Moreover, they can cause maternal and fetal dependency when used chronically. They have also been implicated in intrauterine growth retardation. For these reasons, the FDA pregnancy risk factor category is C. Opiates are also found in low doses in breast milk. Loperamide HCI (lmodium) is another antidiarrheal agent. It is similar to the opiates. However, no animal studies or human reports have revealed any untoward effect of the drug. Thus, the FDA pregnancy risk factor category of loperamide HCl is
Vol. 33, No. 2, March/April 1988
B. Although excreted in breast milk, no problems have been associated with its use. The usual dosage of loperamide is 2-4 mg up to 16 mg in a 24 hour period. Diphenoxylate HCl with atropine sulfate (Lomotil) is a drug that is pharmaceutically similar to opiates. It uses both local and central control to decrease gastrointestinal activity in the effort to stop diarrhea. The atropine combined in the drug is of dubious use, as it is in a subtherapeutic dose. No problems have been identified with its use prenatally for human, although it has been associated with rat intrauterine growth retardation. It is excreted in breast milk even though no clinical problems have been associated with the agent. The usual dose of diphenoxylate HCl with atropine is 5-10 mg up to four times daily. Difenoxin and atropine (Motofen) is more effective than diphenoxylic acid, although it is related to that agent. It is also related to the active metabolite of meperidine. When used in pregnancy, no studies have indicated human teratogenic problems, although rat studies have shown increased stillbirth rate and prolonged delivery time. Difenoxin and atropine are excreted in breast milk and have been associated with maternal habituation after prolonged use. Kaolin and pectin are commonly used in combination therapy as adsorbants. Kaolin adsorbs large amounts of bacteria and toxins and, thus, should reduce loss of water. Pectin is a polymer that is extracted from apples or citrus fruits. Its method of action remains unknown. Kaolin and pectin are commonly available as over-the-counter drugs and are packaged under brand names of Kaopectate, DonnagelMB, or Pecto-Kay. Kaolin and pectin have not been scientifically studied in pregnancy, although no problems have been reported in humans. In fact, kaolin and pectin are almost totally unabsorbed after oral ingestion.
71
Kaolin can decrease absorption of several medications, most prominent among them are theophylline and aminophylline. Therefore, it would be used cautiously, if at all, with asthmatics. The bismuth subsalicylate, marketed as Pepto-Bismol, has been widely advertised as an antidiarrheal agent. Its mode of action as either an adsorbant or inhibitor of intestinal secretions is not well established. However, the salicylates contained in the product suggest that it, like aspirin, should not be recommended in pregnancy. In fact, the use in pregnancy of bismuth subsalicylate, kaolin or pectin must be tempered with information not only about safety, but also about efficacy of the drugs. The USPDI noted research suggesting no decrease in stool frequency, fecal weight, and water content with kaolin and pectin even though the stools were more formed.7 The FDA advisory panel8 in 1975 reported that they were unable to find any scientific rationale for bismuth salts, kaolin, or pectin as effective antidiarrhea1 agents. These findings indicate that diarrhea is best treated first nonpharmaceutically, and then, if needed, with opiates or opiate like agents.
CONCLUSION In conclusion, gastrointestinal system disorders can manifest as a variety of discomforting symptoms in a pregnant woman. Management of such discomforts may be both nonpharmaceutical and pharmaceutical in approach. When a pharmaceutical approach is needed, appreciation of the various agents can assist in identifying the best medication for each situation.
The author would like to give special acknowledgement to the creators and other faculty of the ACNM Maternal Fetal Pharmacology
72
course wherein the interest in this field was first generated. These individuals include Marilynn Frederickson, MD; Sandy Sasso, CNM; Nancy Reedy, CNM; and Carolyn Rout-
ledge,
CNM.
REFERENCES 1. Jarnfelt-Samsioe A: Nausea and vomiting in pregnancy. Obstet Gynecol SUIV 41(7):422-427, 1987. 2. Varney H: Nurse-Midwifery. London, Blackwell, 1980. 3. Moore ML: Realities in childbearing. Philadelphia, Saunders, 1983. 4. Hockenberry MJ, Cotanch PH: Hypnosis as an adjunctive antiemetic therapy in childhood cancer. Nurs Clin North Am 20(1):105-107, 1985. 5. DiPalma JR: Drugs for nausea and vomiting of pregnancy. Am Fam Physician 28(4):272-274, 1983. 6. Dilorio C: First trimester nausea in pregnant teenagers. Nurs Res 34(6):372-374, 1985. 7. United States Pharmacopeial Dispensing Information (USPDI): Drug information for the health care professional, Volume 1, 7th edition. Rockville, MD, U.S. Pharmacopeial Convention, Incorporated, 1987. 8. APA & NPSP: Handbook of nonprescriptive drugs, 7th edition. Washington, American Pharmaceutical Association and the National Professional Society of Pharmacists, 1982. 9. Zimmerman D: The essential guide to nonprescriptive drugs. New York, Harper & Row, 1983. 10. Neeson JD, May KA: Comprehensive maternity nursing: Nursing process and the childbearing family. Philadelphia, Saunders, 1986. 11. AMA: Drug Evaluations, 6th edition. Chicago, American Medical Association, 1986. 12. Nivantvongs S, Wooks VH: Chronic constipation. Postgrad Med 74(5):313-319, 1983. 13. Meeroff JC: Approach to the patient with constipation. Hosp Pratt 20(1):148, 152-153, 1985. 14. Moliton P: Clinical revision: Constipation. Nursing Mirror 160( 19):1820, 1985.
APPENDIX A FDA Risk Factors Category A: Controlled studies in women fail to demonstrate a risk to the fetus in the first trimester (and there is no evidence of a risk in later trimesters), and the possibility of fetal harm appears remote. Category B: Either animal-reproduction studies have not demonstrated a fetal risk but there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the first trimester (and there is no evidence of a risk in later trimesters). Category C: Either studies in animals have revealed adverse effects on the fetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the fetus. Category D: There is positive evidence of human fetal risk, but the benefits from use in pregnant women may be acceptable despite the risk (e.g., if the drug is needed in a life-threatening situation or for a serious disease for which safer drugs cannot be used or are ineffective). Category X: Studies in animals or human beings have demonstrated fetal abnormalities or there is evidence of fetal risk based on human experience or both, and the risk of the use of the drug in pregnant women clearly outweighs any possible benefit. The drug is contraindicated in women who are or may become pregnant. Federal Register 44137434-37467, 1980.
Journal of Nurse-Midwifery
??Vol.
33, No. 2, March/April 1988
APPENDIX B
Common antacids Pharmaceutical
Examples of bmnd names
agent
Alumina, magnesium Alumina, magnesia, calcium carbonate Alumina, magnesium carbonate Alumina, magnesium carbonate, magnesium oxide Alumina, magnesium trisilicate Alumina hydroxide Calcium carbonate, magnesium Calcium, magnesium carbonate Calcium, magnesium carbonates, magnesium oxide Dihydoxyaluminum amniocetate Dihydoxyaluminum amniocetate, magnesium Dihydoxyaluminum sodium carbonate Magaldrate (Mg & Al) Milk of magnesia Magnesium carbonate Magnesium carbonate, sodium bicarbonate Magnesium oxide Magnesium trisilicate, alumina, magnesia Alumina magnesium, simethicone Magaldrate, simethicone Simethicone, alumina, magnesium carbonate, magnesium
Alka Med, Maalox, WinGel Camalox Gavison Suspension Estomil-M Alma Mag, Gavison Tablets Amphojel Bisodel Marblen Alkets Robalate Aluscop Rolaids Riopan, Lowsium Phillips De Witts Bisodel Suspension ParMag, UroMag Magna&i1 Amphogel Plus, Di-Gel, Maalox Plus, Mylanta-II Riorpan Plus Di-Gel Tablets
APPENDIX C
Common laxatives Generic name
Bulk forming category Malt soup Methycellulose Polycarbophil Psyllium Psyllium hydophilic mucilloid Emollient
Examples of brand names Matsupex Cologel Mitrolan Naturacil, Siblin Mucilose, Metamucil
category
Docusate Poloxamer 188 category La&lose Magnesium citrate Magnesium sulfate Sodium phosphate
Dialose, Colace Alaxin
Hyperosmotic
Chronulac Citroma Fleet Phospho-Soda
Lubricant category
Mineral oil Stimulant category Castor oil Cascara sagrada Bisacodyl Danthron Dehydrocholic acid Phenophthalein Senna Sennosides
Journal of Nurse-Midwifery
??
Milkinol Purge
Vol. 33, No. 2. March/April 1988
Dulcolax Modane Cholan-DH Feen-A-Mint, Correct01 Senokot Nytilax
73
Mary C. Brucker, CNM
ABSTRACT The minor discomforts of pregnancy present difficulties for the health care provider as well as for the pregnant woman herself. Management of the various symptoms requires astute observations and the ability to individualize therapy. Knowledge of a variety of treatment options, therefore, allows practitioners to collaborate with their patients in selecting the best therapeutic approach for the specific situation. This three part series reviews the common discomforts associated with upper respiratory infections, minor pain, and gastrointestinal problems as they are manifested during pregnancy. Both nonpharmaceutical and pharmaceutical therapies are discussed. Frequent references are made to the Food and Drug Administration (FDA) Risk Factors which categorize both over-the-counter and prescribed drugs according to their documented safety for ingestion during pregnancy. Part I, “Managing Upper Respiratory Infections in Pregnancy”, appeared in JNM 32:6; Part II, “Managing Minor Pain in Pregnancy”, appeared in JNM 33:l; and Part III, “Managing Gastrointestinal Problems in Pregnancy”, appears in this issue.
Pregnancy affects all of the body’s organ systems to some extent. In this, the last of a three part series on management of common problems in the prenatal period, a system markedly affected by pregnancy is discussed. The affected system is the gastrointestinal tract. Clinical and mechanical changes serve to effect a wide diversity of symptomatology. Common minor discomforts frequently range from heartburn to constipation. Treatment of these complaints are based on the etiologic agent involved, as well as recognition of potential side effects, hazards, and teratogenicity of interventions.
Address correspondence to: Mary C. Btucker, CNM, 9600 Golf Lakes Trail #1004, Dallas, TX 75231. Journal of Nurse-Midwifery
??Vol.
MORNING SICKNESS
Although a single etiologic agent remains unproven, several theories about nausea and vomiting in pregnancy have been proposed. A major commonality of the theories has been the hormonal changes accompanying pregnancy. These hormonal changes include high levels of circulating steroids (e.g., estrogen), and high levels of human chorionic gonadotropin (HCG). It has been proposed that these agents have the ability to directly stimulate the chemoreceptor cells in the postrema of the medulla that are associated with vomiting.’ Other suggested factors have included slowed peristalsis of the gastrointestinal tract, and pressure from the enlarging uterus.2,3 The major treatments of nausea and vomiting in pregnancy are cur-
33, No. 2, March/April 1988
Copyright 0 1988 by the American College of Nurse-Midwives
rently nonpharmaceutical in nature. Small frequent meals, dry crackers upon arising to minimize the emptiness of the stomach, avoidance of strong odors, spicy foods, and very cold liquids are all common instructions. Other suggestions have included ingestion of foods that are sweet before retiring at night, or upon arising; restriction of fats in the diet; as well as separation of fluids from solids. Regardless of the popularity of these treatments, little scientific evidence appears to support their efficacy.l Hockenberry & Cotanch* suggested hypnotic suggestions in their work with nausea in children.* Reassurance is the single most universal, and possibly most effective remedy for the average case of mild morning sickness, as the condition normally dissipates by sixteen weeks of pregnancy.5s6 67 0091-2182/88/$!l3.50
However, there are instances in which the nonpharmaceutical approaches are inadequate. To initiate a pharmaceutical agent in the treatment of nausea and vomiting, the practitioner must consider several factors. These factors include patient desire, severity of the complaint, and reaction to the nonpharmaceutical interventions. The severity of the complaint can be assessed by patient report of interference with activities of normal living including work, or such objective signs as weight loss or urinary ketosis. Until recently, a popular medication for morning sickness was a combination of an antihistamine (doxyiamine succinate) and a vitamin formulation (pyridoxine), sold under the brand name of Bendectin. Although FDA investigation did not demonstrate teratogenic effects of this combination, litigation compelled the manufacturer to remove it from the marketplace.7 It should be noted that the same therapy is still available today by combining the exact same ingredients that are now sold in over-the-counter formulations. However, for the certified nurse-midwife to advise a patient to combine and use these medications is to assume a risk, apparently not of teratogenicity, but of liability. Other nonprescriptive drugs are available as antiemetics. The most common examples exist under the brand names of Emetrol, Especol and Controflex. They are all combinations of sugars (levulose [fructose], sucrose and dextrose) with phos-
Ms. Bruclcer received her Bachelor and Masters’degrees in nursing at St. Louis University. She obtained a certificate in nurse-midwifey from the Univekty of Mississippi. She has practiced nursemidwifery in public and private sectors. She is also a member of the Continuing Education faculty of the American College of Nurse-Midwives (ACNM) for the course on Maternal Fetal Pharmacology.
68
phoric acid added to control the pH. Although their efficacy as treatment for morning sickness has never been demonstrated, they continue to be marketed.879 There is no indication that they would be of harm in pregnancy unless the gravid woman were also diabetic. For the patients who need a pharmaceutical intervention for morning sickness, several options are available. Nausea and vomiting is usually most apparent in the first trimester. Thus, pharmaceutical interventions occur within the most teratogenic period for humans. However, for the women for whom nausea and vomiting pose a risk either to nutrition, as evidenced by significant weight loss, or to ability to conduct a normal life style, judicious use of an antiemetic may prove to break the cycle and prevent more serious consequences. Thus, use could allow her not only to resume activities of daily living, but also potentially allow better nourishment of the intrauterine conceptus who is also being affected. Antiemetics should be carefully evaluated before use in pregnancy. Buclizine is marketed under the name of Bucladin-S. Cyclizine can be purchased as Marezine. Mecliiine is commonly found as Antioerf or Bonine. All three of these pharmaceutical agents are used for motion sickness or nausea and vomiting. They are not commonly used in first trimester of pregnancy as all three have demonstrated some teratogenicity in rats specific to the early part of gestation. Buclizine, cyclizine, and mecliine all function by decreasing labyrinthine functions and may be involved with inhibition of the medullay chemoreceptor zone. Use for women who are breastfeeding should be on an individual basis as the drugs have been found in breast milk although the significance is unknown. Moreover, they may inhibit lactation itself. Scopolamine is a drug that was well established in obstetrics a few
decades ago. It was used intrapartally as an amnesiac in conjunction with analgesics to effect a condition termed “twilight sleep”. Scopolamine is still available, and commonly used as an antiemetic. In fact, it is often administered transdermally through skin patches. Scopolamine is a drug that relaxes smooth gastrointestinal muscles, inhibits the labyrinthine receptors, and decreases conduction in the vestibular cerebellar pathway. There are no indications that scopolamine has any effect on increasing blood pressure or respiration rate. The FDA risk factor rating for scopolamine is category C as no human or animal studies have been undertaken (Appendix A). For use when breastfeeding, there are no specific known neonatal implications. However, the drug is excreted in the breast milk and it has been associated with inhibition of lactation. Promethazine is commonly marketed as Phenergan. This agent is both an antihistamine and a phenothiazine derivative. The theorized method of action to quell nausea and vomiting is inhibition of the chemoreceptor zone in the medulla. A common side effect is drowsiness. There have been no reported teratogenie complications with promethazine. However, the drug is contraindicated in late third trimester. Women who ingest the medication at that time have a risk of increased jaundice for the neonate. This phenomenon is suggested to be related to neonatal deficiency in the ability to detoxify enzymes8s well as insufficient renal enzymes7 Promethazine is excreted in breast milk and theoretically may decrease lactation, as with most antihistamines. Usual dosage is an initial administration of 25 mg, then 12.5-25 mg every four to six hours. Two phenothiazines are of particular assistance in severe nausea and vomiting. These are chlorpromazine and prochlorperazine. The first is marketed as Thorazine, and the latter as Compazine. Thorazine may
Journal of Nurse-Midwifery
??Vol.
33, No. 2, March/April
1988
have a strong connotation being only a psychotropic drug for some care providers. However, Thorazine is a potent major antiemetic. For nausea and vomiting, it is used in a short course, at a lower dosage than for long term psychiatric use. Both phenothiazines inhibit the medullary chemoreceptor zone and are potent antiemetics. Although no studies have indicated first trimester teratogenie effects, the agents are not recommended in late pregnancy for risk of neonatal jaundice. During lactation, small amounts are excreted and they may actually enhance lactation by increasing prolactin secretions. Chlorpromazine and prochlorperazine have a common side effect of drowsiness. For the nauseated woman, the preferred method of administration is either rectal or parenteral. The parenteral dosage may range from 10 to 50 mg b.i.d. up to every four hours. Rectal suppositories of chlorpromazine are administered 50-100 mg three to four times daily. Suppositories for prochlorperazine are usually given 25 mg b.i.d. Unusual side effects have been reported to include muscle spasms, especially of the face; blurred vision; and dyskinesia. 7 HEARTBURN
Another common discomfort of pregnancy associated with gastrointestinal changes is heartburn. In this condition, gastric acids are refluxed or regurgitated into the lower esophagus by reversed peristalsis. The causes of the increased frequency of this condition in pregnancy have included: the effect of progesterone on the cardiac sphincter in the stomach, allowing it to relax; progesterone induced smooth muscle relaxation encouraging decreased gastrointestinal motility; and displacement and compression of the stomach by the enlarging uterus. Nonpharmaceutical interventions for a woman experiencing heartburn are similar to those for a woman with morning sickness.
Journal of Nurse-Midwifery
??
Small frequent meals, separation of fluids from solids, avoidance of fatty, spicy foods, and very cold liquids are common advice.2J0 Additionally, suggestions for straight posture and avoidance of a reclining position for one hour after eating also advocate increasing the functional room for the stomach and decreasing mechanical reasons that encourage heartburn3 The use of milk is quite controversial as it has been reported to be a gastric irritant.* Other ingestible items that can potentiate gastrointestinal irritation and should be limited include smoking, alcohol, coffee, and chocolate. The first two are implicated in other risks in pregnancy. When such advice is not sufficient, the certified nurse-midwife must evaluate whether a pharmaceutical intervention is warranted. Again, the factors will include patient desire and report of severity of the condition. Severe fatigue may also be reported because of interference with sleep. Weight loss may indicate a need for further interventions. When the decision has been made to introduce a pharmaceutical agent, the medication of choice is an antacid. Antacids ideally should have the capability to not only neutralize acid, but be composed of both magnesium and aluminum. Magnesium alone tends to cause diarrhea; whereas aluminum alone is associated with constipation. Calcium has rapid onset and is able to neutralize well, but a condition of rebound hyperacidity is often associated with it. Turns (calcium carTherefore, bonate) may not be a first choice as an antacid, although for nonpregnant women, it is an easily accessible method of obtaining bioavailable calcium to aid in reducing the risks of osteoporosis. In general, the liquid formulations of antacids are more acid neutralizing than tablet form, although not always as convenient. Phosphates are usually slightly less effective than carbonates, hydroxides, or oxides. Simethicone is yet another pharma-
Vol. 33, No. 2, March/April 1988
ceutical agent that is commonly found in antacids. In vitro studies have demonstrated a decrease in surface tension of gas bubbles. Thus, it is proposed to decrease gas for patients using it. However, no clinical studies have firmly established this fact. 7 Because sodium has no therapeutic value for treatment of heartbum, it is advisable to recommend antacids that are low in sodium. Thus, sodium bicarbonate, citral carbonate, or the over-the-counter Alka Seltzer are not to be prescribed because of high sodium levels. Even one of the most commonly prescribed antacid combinations, alumina, magnesium, and simethicone (e.g., Amphojel Plus, Di-Gel, Maalox Plus, Mylar&a-11) can have varying amounts of sodium. The low sodium antacids include magaldrate and magaldrate and simethicone. Appendix B summarizes the content of commonly available antacids. There are no well controlled studies of the use of antacids in pregnancy. However, the studies that have been completed do not associate these pharmaceutical agents with increased congenital anomalies. Chronic use of any of the major components of antacids are associated with potentially major side effects. For example, chronic use of aluminum agents is associated with increased deep tendon reflexes and possibly hypercalcemia; magnesium is associated with decreased muscle tone, and cardiovascular and respiratoy impairment; and calcium with decreased deep tendon reflexes and increased muscle tone. Although aluminum, calcium, simethicone, and magnesium are found in breast milk, the concentration is low. Moreover, there have been no reports of neonatal effects. Because antacids coat the gastrointestinal tract, other agents may be malabsorbed. Among these agents are anticoagulants, salicylates, and vitamin E. Diagnostic tests for serum phosphate, potassium, and calcium
69
levels can all be incorrect if antacids have been used frequently. The general dosages for tablet use are one to eight tablets, chewed thoroughly in divided doses over three to four times daily between meals and at bedtime. When using the liquid form, 5-30 cc are usually prescribed. This varies upon the product and each agent should be scrutinized for recommended dosage.
CONSTIPATION
An annoying minor discomfort of pregnancy is constipation. As with heartburn, one of the most common theories as to its etiology includes the muscular relaxation associated with progesterone as well as mechanical compression and displacement of the bowel by the enlarging uterus. Iron supplementation also may cause constipation. Nonpharmaceutical measures include increased fluids, warm liquids upon arising, bulk and fiber foods in the diet, exercise, and establishment of regular good bowel habits.12J3J4 The major reasons for initiation of a pharmaceutical remedy for constipation include patient desire and inadequacy of the nonpharmaceutical measures. Occasionally constipation will be so severe that pharmaceutical interventions will be started and then the nonpharmaceutical remedies will be used prophylactically to prevent a recurrence. There are five different categories of laxatives available. Most of these can be obtained overthe-counter. All laxatives should be used judiciously, as over-usage can lead to dependancy. Moreover, as laxatives either increase GI emptying time or coat the tract with emollients or gels, food and medications taken at approximately the same time will have diminished effects. In general, the best agents for prophylaxis are bulk, lubricants, and emollients. The best intervention for treatment would be bulk, and rare use of stimulants.
70
In pregnancy, bulk laxatives and emollients appear to have the least potential side effects. The first category is bulk forming laxatives. These absorb water and actually swell in the gastrointestinal system. Bulk laxatives are best used as an initial type of treatment, and should be administered with a full glass of water. Usual time for onset is 12 to 24 hours after administration. Bulk forming laxatives include methylcellulose, psyllium hydrophilic mucilloid, malt soup extract, polycarboPhil, and psyllium. Emollients comprise the second category of laxatives. They are particularly advisable if a hard mass is present. Emollients reduce the surface tension of the liquid contents of the bowel so more fluid goes into the stool itself. Another point of consideration, especially for the patient with hemorrhoids, is that facilitating the passage of stool also can decrease the associated straining. Examples of emollients are docusate and poloxamer 188. These agents usually act after 24 to 48 hours. Emollients potentiate any other laxative. This should be considered if a combination approach is sought. Hyperosmotics are usually subdivided into lactulose or saline. Lactulose hyperosmotics cause an increase in osmolar tension that causes an increase in fluid accumulation, distention, peristalsis, and evacuation Saline hyperosmotics are similar although by using saline they are able to draw water into the lumen that causes the above fluid accumulation. It is also proposed that saline hyperosmotics use the release of cholecystokinin to enhance the laxative effect. Lactulose is an example of hyperosmotics; as are magnesium citrate, magnesium sulfate, and sodium phosphate. Lactulose is effective 24 to 48 hours after administration. The saline hyperosmotics have the shortest peak time, of 30 minutes to three hours. Thus, they are not advisable to be administered before bedtime and they also can promote
sodium retention with edema resulting in pregnancy. Lubricants are similar to emollients, and actually are no more or less effective than those. These agents coat the stools and the intestines with a water immiscible film. Thus, there is an increased accumulation of water in the stool itself. These are usually effective six to eight hours after administration. A traditional lubricant is mineral oil. Mineral oil often is not recommended in pregnancy for constipation because long term use of the medication can interfere with absorption of fat soluble vitamins. Stimulants are yet another category of laxatives and are rarely needed in pregnancy. They tend to cause cramping as they actually stimulate the GI system. This in turn causes additional patient discomfort. The exact mechanism of action is unknown although it is theorized that the intramural nerve plexis is irritated. The USPDI suggested that such stimulants as castor oil are contraindicated for treatment of constipation, as “its use often results in pelvic area engorement which may initiate reflex stimulation of the gravid uterus.“7 Examples of stimulants used to treat constipation are: castor oil, cascara sagrada, bisacodyl, danthron, dehydrocholic acid, phenolphthalein, senna, sennosides. Appendix C lists generic and brand names of laxatives. There are no current teratogenic links with the use of laxatives in pregnancy. Few studies have been conducted in the area. For breastfeeding mothers, cascara sagrada and danthron have each had reported cases of loose stools in the infants. When using laxatives, there are drug interactions with diuretics (decreased serum potassium) and anticoagulants (decreased effect due to physical binding). Salicylates are particularly affected by bulk forming agents. These agents decrease the effectiveness of the salicylates.
Journal of Nurse-Midwifery
??Vol.
33, No. 2, March/April 1988
Chronic use of emollients with danthron have been associated with liver damage. All laxatives are contraindicated in the presence of appendicitis, rectal bleeding, congestive heart failure, fecal impaction, and intestinal obstruction. Laxatives may also contain high levels of sugar as well as sodium. Psyllium has had up to 50% dextrose and effervescent laxatives may have up to 250 mg of sodium. The common dosage for laxatives is one to three tablets at bedtime or for one dosage. Liquid dosage depends on the pharmaceutical agent involved and usually ranges from 5 to 60 cc. DIARRHEA
Diarrhea is not usually listed as a common minor discomfort of pregnancy, but in practice it commonly exists. Often it is of a food origin. Occasionally it is a side effect of an influenza viral disease. Although a pregnant woman is not at increased risk for diarrhea when compared with her nonpregnant counterpart, she may be at increased risk for influenza if she is already a mother. Being a mother increases her proximity to a variety of illnesses from her offspring. Thus, it is not unlikely that the certified nurse-midwife will be faced with a patient complaining of diarrhea in pregnancy. Diarrhea is a situation in which nonpharmaceutical agents are clearly the interventions of choice. The acute short term diarrhea is best treated with tincture of time. Whether it be due to infection or maldigestion, it is usually a self limiting crisis, Common etiologic agents may include E. coli, Staphylococci, or Salmonella. The basic supportive therapy is fluid replacement. High fiber foods should be avoided. Thus, such foods as unrefined cereals, fruits, and vegetables are to be limited, as well as lactose containing foods. The side effects of an episode of
Journal of Nurse-Midwifery
??
diarrhea may range from minor patient discomfort to perianal irritation, hemorrhoidal irritation, dehydration, and hypokalemia. Dehydration is of particular concern in pregnancy with its association with preterm labor. Thus, replacement fluid should be sought with vigor to prevent this complication. Rarely, diarrhea does not respond itself to palliative treatment in 24 to 48 hours. In those cases a diagnosis of a more severe gastrointestinal condition as inflammatory bowel syndrome should be entertained. Introduction of an antidiarrheal pharmaceutical agent depends upon such factors as duration and severity of the condition, patient desire, and risk of dehydration among others. The basic types of antidiarrheals include opiates and adsorbants. Opiates slow the gastrointestinal motility and prolong transit time. This is accomplished by interactions with the central opiate receptors. A purified opioid such as codeine is as effective as an antidiarrheal agent as a camphorated opium tincture (Paregoric). Opiates are slightly more effective than their pharmaceutically related compounds of diphenoxylate with atropine (Lomotil) or difenoxin and atropine (Motofen). Codeine sulfate or phosphate can be administered as an antidian-heal at a dose of 15-60 mg every 4 to 8 hours. Opium tincture (Paregoric) is usually 5-10 mg up to four times daily. Opiates pass the placental barrier. Moreover, they can cause maternal and fetal dependency when used chronically. They have also been implicated in intrauterine growth retardation. For these reasons, the FDA pregnancy risk factor category is C. Opiates are also found in low doses in breast milk. Loperamide HCI (lmodium) is another antidiarrheal agent. It is similar to the opiates. However, no animal studies or human reports have revealed any untoward effect of the drug. Thus, the FDA pregnancy risk factor category of loperamide HCl is
Vol. 33, No. 2, March/April 1988
B. Although excreted in breast milk, no problems have been associated with its use. The usual dosage of loperamide is 2-4 mg up to 16 mg in a 24 hour period. Diphenoxylate HCl with atropine sulfate (Lomotil) is a drug that is pharmaceutically similar to opiates. It uses both local and central control to decrease gastrointestinal activity in the effort to stop diarrhea. The atropine combined in the drug is of dubious use, as it is in a subtherapeutic dose. No problems have been identified with its use prenatally for human, although it has been associated with rat intrauterine growth retardation. It is excreted in breast milk even though no clinical problems have been associated with the agent. The usual dose of diphenoxylate HCl with atropine is 5-10 mg up to four times daily. Difenoxin and atropine (Motofen) is more effective than diphenoxylic acid, although it is related to that agent. It is also related to the active metabolite of meperidine. When used in pregnancy, no studies have indicated human teratogenic problems, although rat studies have shown increased stillbirth rate and prolonged delivery time. Difenoxin and atropine are excreted in breast milk and have been associated with maternal habituation after prolonged use. Kaolin and pectin are commonly used in combination therapy as adsorbants. Kaolin adsorbs large amounts of bacteria and toxins and, thus, should reduce loss of water. Pectin is a polymer that is extracted from apples or citrus fruits. Its method of action remains unknown. Kaolin and pectin are commonly available as over-the-counter drugs and are packaged under brand names of Kaopectate, DonnagelMB, or Pecto-Kay. Kaolin and pectin have not been scientifically studied in pregnancy, although no problems have been reported in humans. In fact, kaolin and pectin are almost totally unabsorbed after oral ingestion.
71
Kaolin can decrease absorption of several medications, most prominent among them are theophylline and aminophylline. Therefore, it would be used cautiously, if at all, with asthmatics. The bismuth subsalicylate, marketed as Pepto-Bismol, has been widely advertised as an antidiarrheal agent. Its mode of action as either an adsorbant or inhibitor of intestinal secretions is not well established. However, the salicylates contained in the product suggest that it, like aspirin, should not be recommended in pregnancy. In fact, the use in pregnancy of bismuth subsalicylate, kaolin or pectin must be tempered with information not only about safety, but also about efficacy of the drugs. The USPDI noted research suggesting no decrease in stool frequency, fecal weight, and water content with kaolin and pectin even though the stools were more formed.7 The FDA advisory panel8 in 1975 reported that they were unable to find any scientific rationale for bismuth salts, kaolin, or pectin as effective antidiarrhea1 agents. These findings indicate that diarrhea is best treated first nonpharmaceutically, and then, if needed, with opiates or opiate like agents.
CONCLUSION In conclusion, gastrointestinal system disorders can manifest as a variety of discomforting symptoms in a pregnant woman. Management of such discomforts may be both nonpharmaceutical and pharmaceutical in approach. When a pharmaceutical approach is needed, appreciation of the various agents can assist in identifying the best medication for each situation.
The author would like to give special acknowledgement to the creators and other faculty of the ACNM Maternal Fetal Pharmacology
72
course wherein the interest in this field was first generated. These individuals include Marilynn Frederickson, MD; Sandy Sasso, CNM; Nancy Reedy, CNM; and Carolyn Rout-
ledge,
CNM.
REFERENCES 1. Jarnfelt-Samsioe A: Nausea and vomiting in pregnancy. Obstet Gynecol SUIV 41(7):422-427, 1987. 2. Varney H: Nurse-Midwifery. London, Blackwell, 1980. 3. Moore ML: Realities in childbearing. Philadelphia, Saunders, 1983. 4. Hockenberry MJ, Cotanch PH: Hypnosis as an adjunctive antiemetic therapy in childhood cancer. Nurs Clin North Am 20(1):105-107, 1985. 5. DiPalma JR: Drugs for nausea and vomiting of pregnancy. Am Fam Physician 28(4):272-274, 1983. 6. Dilorio C: First trimester nausea in pregnant teenagers. Nurs Res 34(6):372-374, 1985. 7. United States Pharmacopeial Dispensing Information (USPDI): Drug information for the health care professional, Volume 1, 7th edition. Rockville, MD, U.S. Pharmacopeial Convention, Incorporated, 1987. 8. APA & NPSP: Handbook of nonprescriptive drugs, 7th edition. Washington, American Pharmaceutical Association and the National Professional Society of Pharmacists, 1982. 9. Zimmerman D: The essential guide to nonprescriptive drugs. New York, Harper & Row, 1983. 10. Neeson JD, May KA: Comprehensive maternity nursing: Nursing process and the childbearing family. Philadelphia, Saunders, 1986. 11. AMA: Drug Evaluations, 6th edition. Chicago, American Medical Association, 1986. 12. Nivantvongs S, Wooks VH: Chronic constipation. Postgrad Med 74(5):313-319, 1983. 13. Meeroff JC: Approach to the patient with constipation. Hosp Pratt 20(1):148, 152-153, 1985. 14. Moliton P: Clinical revision: Constipation. Nursing Mirror 160( 19):1820, 1985.
APPENDIX A FDA Risk Factors Category A: Controlled studies in women fail to demonstrate a risk to the fetus in the first trimester (and there is no evidence of a risk in later trimesters), and the possibility of fetal harm appears remote. Category B: Either animal-reproduction studies have not demonstrated a fetal risk but there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the first trimester (and there is no evidence of a risk in later trimesters). Category C: Either studies in animals have revealed adverse effects on the fetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the fetus. Category D: There is positive evidence of human fetal risk, but the benefits from use in pregnant women may be acceptable despite the risk (e.g., if the drug is needed in a life-threatening situation or for a serious disease for which safer drugs cannot be used or are ineffective). Category X: Studies in animals or human beings have demonstrated fetal abnormalities or there is evidence of fetal risk based on human experience or both, and the risk of the use of the drug in pregnant women clearly outweighs any possible benefit. The drug is contraindicated in women who are or may become pregnant. Federal Register 44137434-37467, 1980.
Journal of Nurse-Midwifery
??Vol.
33, No. 2, March/April 1988
APPENDIX B
Common antacids Pharmaceutical
Examples of bmnd names
agent
Alumina, magnesium Alumina, magnesia, calcium carbonate Alumina, magnesium carbonate Alumina, magnesium carbonate, magnesium oxide Alumina, magnesium trisilicate Alumina hydroxide Calcium carbonate, magnesium Calcium, magnesium carbonate Calcium, magnesium carbonates, magnesium oxide Dihydoxyaluminum amniocetate Dihydoxyaluminum amniocetate, magnesium Dihydoxyaluminum sodium carbonate Magaldrate (Mg & Al) Milk of magnesia Magnesium carbonate Magnesium carbonate, sodium bicarbonate Magnesium oxide Magnesium trisilicate, alumina, magnesia Alumina magnesium, simethicone Magaldrate, simethicone Simethicone, alumina, magnesium carbonate, magnesium
Alka Med, Maalox, WinGel Camalox Gavison Suspension Estomil-M Alma Mag, Gavison Tablets Amphojel Bisodel Marblen Alkets Robalate Aluscop Rolaids Riopan, Lowsium Phillips De Witts Bisodel Suspension ParMag, UroMag Magna&i1 Amphogel Plus, Di-Gel, Maalox Plus, Mylanta-II Riorpan Plus Di-Gel Tablets
APPENDIX C
Common laxatives Generic name
Bulk forming category Malt soup Methycellulose Polycarbophil Psyllium Psyllium hydophilic mucilloid Emollient
Examples of brand names Matsupex Cologel Mitrolan Naturacil, Siblin Mucilose, Metamucil
category
Docusate Poloxamer 188 category La&lose Magnesium citrate Magnesium sulfate Sodium phosphate
Dialose, Colace Alaxin
Hyperosmotic
Chronulac Citroma Fleet Phospho-Soda
Lubricant category
Mineral oil Stimulant category Castor oil Cascara sagrada Bisacodyl Danthron Dehydrocholic acid Phenophthalein Senna Sennosides
Journal of Nurse-Midwifery
??
Milkinol Purge
Vol. 33, No. 2. March/April 1988
Dulcolax Modane Cholan-DH Feen-A-Mint, Correct01 Senokot Nytilax
73