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Use of fenoterol to delay preterm labor and to promote fetal growth in twin pregnancies
230 Correspondence
Use of fenoteroi to deiay preterm iabor and to promote fetal growth in twin pregnancies .. To the Editors:
The recent report by Marivate, de Villiers, and Fairbrother1 precludes the conclusions that orai fenoteroi has no benefit in delaying preterm labor or in promoting fetal growth in twin pregnancies. The 5 mg. daily oral dose of fenoterol does not offer an adequate 24 hour drug level. 2 Further, this dose of oral fenoterol is effective in decreasing oxytocin-induced contractions by 70 per cent, but over a relatively short period of time. 3 A commonly used dosage of fenoterol is 20 mg. per day in divided dosages. When fenoterol is given as an oral tablet, a good correlation exists between the time of onset of the uterine effects and the maternai puise rate. 3 Furthermore, the return to the original pulse rate stays in a direct significant correlation with the tocolytic response whether the drug is given as an intravenous bolus, 4 an intravenous infusion, 5 or as an aerosol. 6 Maternal pulse rate, therefore, can be used as a clinical guide to adjust the dosage of fenoterol at the start of therapy. The late entry of patients into the study (approximately 32 weeks' gestation) and the authors' finding of almost double the number of growth-retarded fetuses in the placebo group, which was not significant due to the relatively small number of patients in the trial, certainly cannot lead to the conclusion that fenoterol is ineffective in promoting fetal growth in twin pregnanCies. Finally, repeated experience with protracted studies of ambulatory patients who are receiving oral medication and who are not iii ieads to the conclusion that such studies are worthless unless a marker is employed to assess and assure patient compliance. Jeffrey Lipshitz, M.B., M.R.C.O.G., F.A.C.O.G. Jack M. Schneider, M.D., F.A.C.O.G. Division if Maternal-Fetal Medicine Department of Obstetrics and Gynecology The University if Tennessee Center for the Health Sciences 800 Madison Avenue Memphis, Tennessee 38163
REFERENCES i. Marivate, M., de Villiers, K. Q., and Fairbrother, P.: Effect
of prophylactic outpatient administration of fenoterol on the time of onset of spontaneous labor and fetal growth rate in twin pregnancy, AM. J. 0BSTET. GYNECOL. 128: 707, 1977.
2. Buchelt, L., and Rominger, K. L.: The pharmacokinetics and metabolism of Berotec (fenoterol) in man, Med. Proc. 18: 15, 1972.
3. Lipshitz, ].: The uterine and cardiovascular effects of oral fenoterol hydrobromide, Br. J. Obstet. Gynaecol. 84: 737, 1977.
4. Lipshitz, J., Baillie, P., and Davey, D. A.: A comparison of the uterine beta.-adrenoreceptor selectivity of fenoterol,
May IS, 1978 Am. J Obstet. GynecoL
hexoprenaline, ritodrine and salbutamol, S. Afr. Med. J. 50: 1969, 1976.
5. Lioshitz. T.. and Baillie. P.: The uterine and cardiovascular effects ~{ beta.-selecti~e sympathomimetic drugs administered as an intravenous infusion, S. Afr. Med. J. 50:1973, 1976.
J., and Baillie, P.: The effects of the fenoterol hydrobromide (Partusisten) aerosol on uterine activity and the cardiovascular system, Br. J. Obstet. Gynaecol. 83: 864,
6. Lipshitz, 1976.
Incompetent cervical os To the Editors:
As a medical student and, therefore, relative newcomer to the field of clinical medicine, I frequently feel "incompetent" to discuss topics of current medical debate. It is from this perspective, however, that I wholeheartedly agree with Dr. Charles Goodstein (THIS JoURNAL 130: 243, 1978) that the term "incompetent cervical os" may add unnecessary emotional strain to a woman who may already have serious doubts about her "competence" to bear children. In contemplating a change in terminology, I think it is important to convey the potential seriousness of the condition without suggesting any personal inadequacy of the patient. I suggest the simple descriptive term "premature cervical dilatation." Robert W. House 7915 S.W. Oleson Road Portland, Oregon 97223
To the Editors: Following Dr. Goodstein's advice to replace ''cervical
incompetence" by a better terminology, I suggest cervical "weakness," "insufficiency," or "hypotony," depending upon one's preference or, should we say, etymologic "competence". ]. Lemay, M.D. Obstetrics and Gynecology 168 Charlotte Ottawa, Ontario, Canada K1 N 8K6
Response to the letter by Drs. Wolf and Rubinstein regarding the safety of preataglandtn F2 ,. In abortion To the Editors:
We read with interest the letter from Drs. Wolf and Rubinstein (AM. J. OBSTET. GYNECOL. 129: 928, 1977) commenting on our previous article describing abortion deaths associated with the use of prostaglandin F 2a (PGF 2a). Unfortunately it contained some misleading statements that we would like to correct. As stated in our original article (AM. J. 0BSTET. GYNECOL. 127:219, 1977), we agree with Drs. Wolf and Rubinstein that administration of PGF 2., was often
Use of fenoteroi to deiay preterm iabor and to promote fetal growth in twin pregnancies .. To the Editors:
The recent report by Marivate, de Villiers, and Fairbrother1 precludes the conclusions that orai fenoteroi has no benefit in delaying preterm labor or in promoting fetal growth in twin pregnancies. The 5 mg. daily oral dose of fenoterol does not offer an adequate 24 hour drug level. 2 Further, this dose of oral fenoterol is effective in decreasing oxytocin-induced contractions by 70 per cent, but over a relatively short period of time. 3 A commonly used dosage of fenoterol is 20 mg. per day in divided dosages. When fenoterol is given as an oral tablet, a good correlation exists between the time of onset of the uterine effects and the maternai puise rate. 3 Furthermore, the return to the original pulse rate stays in a direct significant correlation with the tocolytic response whether the drug is given as an intravenous bolus, 4 an intravenous infusion, 5 or as an aerosol. 6 Maternal pulse rate, therefore, can be used as a clinical guide to adjust the dosage of fenoterol at the start of therapy. The late entry of patients into the study (approximately 32 weeks' gestation) and the authors' finding of almost double the number of growth-retarded fetuses in the placebo group, which was not significant due to the relatively small number of patients in the trial, certainly cannot lead to the conclusion that fenoterol is ineffective in promoting fetal growth in twin pregnanCies. Finally, repeated experience with protracted studies of ambulatory patients who are receiving oral medication and who are not iii ieads to the conclusion that such studies are worthless unless a marker is employed to assess and assure patient compliance. Jeffrey Lipshitz, M.B., M.R.C.O.G., F.A.C.O.G. Jack M. Schneider, M.D., F.A.C.O.G. Division if Maternal-Fetal Medicine Department of Obstetrics and Gynecology The University if Tennessee Center for the Health Sciences 800 Madison Avenue Memphis, Tennessee 38163
REFERENCES i. Marivate, M., de Villiers, K. Q., and Fairbrother, P.: Effect
of prophylactic outpatient administration of fenoterol on the time of onset of spontaneous labor and fetal growth rate in twin pregnancy, AM. J. 0BSTET. GYNECOL. 128: 707, 1977.
2. Buchelt, L., and Rominger, K. L.: The pharmacokinetics and metabolism of Berotec (fenoterol) in man, Med. Proc. 18: 15, 1972.
3. Lipshitz, ].: The uterine and cardiovascular effects of oral fenoterol hydrobromide, Br. J. Obstet. Gynaecol. 84: 737, 1977.
4. Lipshitz, J., Baillie, P., and Davey, D. A.: A comparison of the uterine beta.-adrenoreceptor selectivity of fenoterol,
May IS, 1978 Am. J Obstet. GynecoL
hexoprenaline, ritodrine and salbutamol, S. Afr. Med. J. 50: 1969, 1976.
5. Lioshitz. T.. and Baillie. P.: The uterine and cardiovascular effects ~{ beta.-selecti~e sympathomimetic drugs administered as an intravenous infusion, S. Afr. Med. J. 50:1973, 1976.
J., and Baillie, P.: The effects of the fenoterol hydrobromide (Partusisten) aerosol on uterine activity and the cardiovascular system, Br. J. Obstet. Gynaecol. 83: 864,
6. Lipshitz, 1976.
Incompetent cervical os To the Editors:
As a medical student and, therefore, relative newcomer to the field of clinical medicine, I frequently feel "incompetent" to discuss topics of current medical debate. It is from this perspective, however, that I wholeheartedly agree with Dr. Charles Goodstein (THIS JoURNAL 130: 243, 1978) that the term "incompetent cervical os" may add unnecessary emotional strain to a woman who may already have serious doubts about her "competence" to bear children. In contemplating a change in terminology, I think it is important to convey the potential seriousness of the condition without suggesting any personal inadequacy of the patient. I suggest the simple descriptive term "premature cervical dilatation." Robert W. House 7915 S.W. Oleson Road Portland, Oregon 97223
To the Editors: Following Dr. Goodstein's advice to replace ''cervical
incompetence" by a better terminology, I suggest cervical "weakness," "insufficiency," or "hypotony," depending upon one's preference or, should we say, etymologic "competence". ]. Lemay, M.D. Obstetrics and Gynecology 168 Charlotte Ottawa, Ontario, Canada K1 N 8K6
Response to the letter by Drs. Wolf and Rubinstein regarding the safety of preataglandtn F2 ,. In abortion To the Editors:
We read with interest the letter from Drs. Wolf and Rubinstein (AM. J. OBSTET. GYNECOL. 129: 928, 1977) commenting on our previous article describing abortion deaths associated with the use of prostaglandin F 2a (PGF 2a). Unfortunately it contained some misleading statements that we would like to correct. As stated in our original article (AM. J. 0BSTET. GYNECOL. 127:219, 1977), we agree with Drs. Wolf and Rubinstein that administration of PGF 2., was often