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Anticonvulsants
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Relative Bioavailability of Two Different Phenytoin Pharmaceutical Formulas- Especially in Relation to Age-
Antiepileptic Effects of Clobazam in Children
Makoto Matsukura, MD, Tetsuo Ikeda, MD, Akimasa Higashi, MD, and Jchiro Matsuda, MD Department of Pediatrics, Kumamoto University, School of Medicine, Kumamoto Patients with epilepsy treated with phenytoin were classified into three groups depending on age, group I (0-5 yrs), group II (6-10 yrs) and group III (above 11 yrs). Studies are done at steady-state phase of phenytoin treatment by oral administration. The Vmax/F of Aleviatin® (Dainippon Co Ltd) powder and Hydantol® (Fujinaga Co Ltd) 25 mg tablet in each group is calculated from the following equation: F. D= Vmax·L Krn + L L/D=~+ __l_.L Vmax/F Vmax/F
F : Fraction of absorbed drug, D: dose (mg/kg·day), L: serum level of phenytoin, Vmax and Krn: MichaelisMenten kinetic parameters. In each age group , regression analysis is used to calculate the averaged values of Vmax/F of two different phenytoin pharmaceutical formula s. Percent of Vmax/F of Aleviatin® to Hydantol® are 65% (group I), 74% (group II) and 78% (group III). Based on the assumption that average Vmax is not different among two subgroups of same age group, who administer Aleviatin® or Hydantol®, it might be concluded that percent of absorbed dose of Aleviatin® is much less than that of Hydantol® in infants, compared with aged children and adults.
Key words: Bioavailability, phenytoin, serum con· centration.
Hiroshi Shimizu, MD, lira Abe, MD, Yasuyuki Futagi, MD, Sachiko Onoe, MD, Tatsuzo Tagawa, MD, Takashi Mimaki, MD, Hyakuji Yabuuchi, MD, Mori· fusa Kamio, MD, Kiyoomi Sumi, MD, Takahiro Sugita, MD, Atsushi Yamatodani, MD, and Masahiro Kato, MD Department of Pediatrics (HS, lA, YF, SO, TT, TM, HY, MK, KS, TS) and 2nd Pharmacology (A Y), Osaka University , Medical School, Osaka; Department of Pediatrics, Kansai Rosai Hospital, Amagasaki, Hyogo (MK) Many benzodiazepines used as anticonvulsants have nitrogen radicals in positions 1 and 4. Clobazam has nitrogen radicals in positions 1 and 5. We studied clobazam as antiepileptics in 36 patients with intractable epilepsies in childhood. Their ages were 1 year 1 month to 16 years 5 months (mean, 8 years). The types of epilepsies were primary generalized epilepsy (2 cases), secondary generalized epilepsy (29 cases) and partial epilepsy (5 cases). The patients were started on daily doses of 0.33 mg/kg and the dosage was increased to 0.71 mg/kg. Nine cases (primary generalized epilepsy 2/2, secondary generalized epilepsy 7/29) of the patients were completely free from seizures, and another 9 cases (secondary generalized epilepsy 8/29, partial epilepsy 1/5) experienced a decrease of 50% or more in seizure frequency. Sixteen cases did not change, and 2 cases (secondary generalized epilepsy 2/29) worsened. We observed the antiepileptic effects on the first day to 10th day after clobazam treatment. Four cases out of 9 patients who were completely free from seizures reappeared, the effects in 3 cases lasted for only a month and in 1 case it lasted for 10 months. Mean serum clobazam level of 7 effective cases was 73 ng/ml and that of noneffective cases was 94 ng/m!. Although we observed mild and transient clinical side effects such as drowsiness in 17 cases, no patients showed abnormality of laboratory findings.
Key words: Clobazam, epilepsy, serum level.
260 Brain & Development, Vol 4, No 3-4,1982
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Effects of Antiepileptic Drugs on Benzodiazepine Receptors in Rat Brain
Clinical Pharmacokinetics of Nitrazepam Using High-Pressure Liquid Chromatography
Takashi Mimaki, MD, Henry 1. Yamamura, PhD, and Hyakuji Yabuuchi, MD Department of Pediatrics, Osaka University, Medical School, Osaka (TM, HY); Department of Pharmacology, University of Arizona, Tucson, USA (H!Y) Benzodiazepine receptors appear to possess a variety of pharmacologic actions on the mammalian central nervous system including anxiolytic, hypnotic, anticonvulsant and muscle relaxant activities. In the present investigation, we determined the effects of acute administration of valproic acid (Vp A), aminooxyacetic acid (AOAA), phenytoin (PHT), phenobarbital (PB) and diazepam (DZP) on specific 3H-f1unitrazepam binding in rat cerebral cortices.
Materials and Methods In these experiments, male Sprague-Dawley rats (about 200 g body weight) were used as experimental animals. Animals received a single ip injection of VP A (100-500 mg/kg), AOAA (50 mg/kg), PHT (100200 mg/kg), PB (50 mg/kg), DZP (50 mg/kg) or 1 ml/kg of control vehicle, and were sacrificed one hour after injection. 3H-f1unitrazepam binding was determined by filter binding assay. Results In VPA (100 mg/kg) treated rats, there was a 11.3 % increase in benzodiazepine receptor density (Bmax). This effect appeared to be dose-dependent as higher doses of VPA (200-500 mg/kg) resulted in a greater increase in Bmax. No change in dissociation constant (Kd) occurred after pretreatment of animals with varying doses of VPA. On the other hand, AOAA (50 mg/kg) treated rats showed a 34.3 % increase in Bmax with a significant decrease in Kd. However, acute administration of PHT (100-200 mg/kg), PB (50 mg/kg) or DZP (50 mg/kg) did not produce any changes in either Bmax or Kd. Additional experiments indicate that VPA or PB has no effects in vitro on specific 3H-flunitrazepam binding. On the other hand, we observed a competitive inhibitory effect of PHT on specific 3H_ f1unitrazepam binding in vitro. In the cerebral cortex, 100/.lM of PHT caused a 32% decrease in specific 3H-f1unitrazepam binding. Conclusions 1) Acute VPA administration produced a dosedependent increase in 3H-f1unitrazepam binding (Bmax) in rat cerebral cortex. 2) Acute AOAA administration resulted in a significant increase in Bmax with a significant decrease in Kd. 3) No significant changes occurred in either Bmax or Kd after acute PHT, PB or DZP administration. 4) PHT inhibits specific 3H-f1unitrazepam binding competitively in vitro. 5) Alterations in benzodiazepine receptor binding in rat brain may correlate with the mechanism of anticonvulsant action of VP A, AOAA and PHT.
Yukihiko Katafuchi, MD, Nobuyuki Aoki, MD, Eiji Yano , MD, Toyojiro Matsuishi, MD, Fumio Yamashita, MD, and Hiroyuki Haraguchi, MD Department of Pediatrics and Child Health , Kurume University , School of Medicine, Kurume, Fukuoka (YK, NA, EY, TM, FY); Department of Pediatrics, The Center of Developmental Medicine and Education of Kitakyushu City, Kitakyushu , Fukuoka (HH) Serum levels of nitrazepam (NZP) in 60 epileptic children ranging in age from 6 months to 18 years were investigated by high-pressure liquid chromatography and the influence of age and phenobarbital (PB) or sodium valproate (VPA) on the serum NZP level were studied. Moreover, in 9 patients (NZP alone, 2 cases; NZP with PB, 3 cases; NZP with VPA, 4 cases), serum half-lives of nitrazepam were also calculated.
Materials and Methods Sixty epileptic children included 30 cases with severe handicaps without any change in the prescription for at least the last 1 month were selected for our study. Blood sampling for the determination of serum NZP level was performed 3 hours after the morning dose. In 9 patients for the calculation of nitrazepam halflives, blood sampling was performed 10, 12, 14 and 16 hours after the last night dose (the morning dose was omitted). Our method - Simultaneous highpressure liquid chromatographic determination of 5 antiepileptic drugs in serum was carried out for this study. Conclusion The following conclusions were made. 1) The serum nitrazepam level was well correlated with the daily dose in 60 epileptic children with a correlation coefficient of 0.683 (p < 0.01). 2) The 60 patients were divided into 3 groups comprising 13 treated with NZP alone, 24 with NZP + PB and 23 with NZP + VPA, and the coefficients of correlation between serum level and dose were 0.955 (p < 0.01), 0.968 (p < 0.001) and 0.959 (p < 0.001), respectively. Treatment with NZP + PB showed a significantly higher serum level than that with NZP alone and that with NZP + VPA showed a lower level. 3) Divided into 3 groups according to age, the regression lines were much the same, although no significant correlation coefficient was obtained. 4) Serum half-lives of nitrazepam were significantly different in the 3 groups (NZP alone, 10.2 ± 0.3 hours; NZP + PB, 25 .6 ± 4.9 hours; NZP + VPA, 6.3 ± 1.2 hours). Key words: Nitrazepam, clinical pharmacokinetics, high-pressure liquid chromatography.
Key words: Benzodiazepine receptors, antiepileptic drugs, !lunitrazepam.
Brain & Development, Vol 4, No 3-4, 1982 261
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Plasma Levels of Valproic Acid and Its Metabolism in Neonatal Convulsions: Application of a GLC-Micromethod
A simple Method using Ultrafiltration Membranes to Measure Free Antiepileptic Drug Concentrations
Nobuo Koide, MD, Yukinao Take be, MD, Satoshi Haneda, MD, and fun Watanabe, MD Department of Pediatrics, Hirosaki University, School of Medicine, Hirosaki, Aomori The microdetermination method for plasma valproic acid (VPA) by gas liquid chromatography (GLCmicromethod) requiring only 50/.11 of plasma samples drawn from the heel or auricle was first modified by the authors. The values for plasma VPA determined by the GLC-micromethod were compared with those by the ordinary GLC-method (GLC) and by the homogeneous enzyme immunoassay (EMIT). Plasma VPA levels in 8 cases with neonatal convulsions were chronologically investigated using the GLC-micromethod.
Methods Capillary blood samples in 2 Hct tubes were centrifuged for 5 minutes at 10,000 rpm. Fifty microliters of plasma samples was vigorously mixed for 30 seconds with 150/.11 of 10% TCA and 200/.11 of diphenylchloroform (5 /.Ig/ml). After centrifugation, about 3 /.II of the organic phase was prepared for the GLC-micromethod. Results The same blood samples were used for determinations by three different methods, i.e., the GLC-micromethod, GLC and EMIT. The correlation between the values by each pair of methods was excellent (p < 0.001) ranging from 0 to 187 /.Ig/ml in 30 cases' (n = 30) in total. The correlation between the values for capillary blood by the GLC-micromethod (P) and those for venous blood by GLC (V) was as follows (n = 50). Both blood samples were collected at the same time. P = 1.01 V - 0.99 (r = 0.98, p < 0.001). In 16 cases of from 1 day to 24 months of age, the correlation between the values determined by the above 2 methods was as follows. P = 1.01 V - 1.97 (r = 0.99, p < 0.001). Conclusion
1) VPA absorption was also good in the neonatal
period. 2) The half-life of VP A was long in the neonatal period, especially in infants of 1 to 2 weeks of age and in preterm infants. A few cases showed VPA accumulation in plasma, including a case with the highest value of 257 /.Ig/ml (Cmin) with a half-life at about 4 days. 3) Plasma VPA levels of 60-100/.lg/ml (Cmin) could be maintained with the dosage of 15-20 mg/kg/ day. 4) Repeated monitoring of plasma VP A levels is mandatory in the neonatal period. 5) The GLC-micromethod is satisfactory for clinical use because it is an accurate, less-invasive and timesaving procedure.
Key words: Valproic acid, gas liqUid chromatography, GLC-micromethod, neonatal convulsions.
262 Brain & Development, Vol 4, No 3-4,1982
Sonsu Lee, MD, Ryosuke Murata, MD, Osamu Matsuoka, MD, Masayoshi Kin, MD, Mayumi Tani, MD, Gen Isshiki, MD, and Yasuo Horiuchi, MD Department of Pediatrics, Osaka City University , Medical School, Osaka (SL, RM, OM, MK, MT, GI); Department of Pediatrics, Children's Medical Center of Osaka City, Osaka (YH) It is only nonprotein bound anticonvulsant drugs that
can produce the desired physiologic or therapeutic effects in epilepsy. Changes in patient health status, additional drug intake, individual peculiarities, or multiple drug therapies can alter the extent of drugprotein binding and thus affect the pharmacologically important nonprotein bound (free) drug level. We measured free phenobarbital (PB) levels in the plasma of epileptic children. Twenty plasma samples were freshly drawn and heparinized, and 56 had been drawn 1-2 weeks earlier and frozen. The samples were filtered through an Ultrafree Anticonvulsant Drug Filter (Worthington), each sample taking 45-90 minutes. The amount of albumin which passed through the filter membrane was measured on an ImmuneDiffuse Plate (Behring). Subsequently, PB levels of cerebrospinal fluid (CSF) were measured and compared to the plasma free levels. The PB levels were measured by the EMIT technique. The results were as follows: 1) The ratio of free plasma PB level and total plasma PB level (F%) was 54.8 ± 8.54% (mean ± SD) in 76 specimens. F% for 16 samples from patients treated with PB alone was 50.9 ± 5.68%. F% for 60 samples with both PB and other antiepileptic drugs was 55.8 ± 8.88%. F % for 12 samples with PB and sodium valproate was 61.1 ± 7.78%. 2) The ratio of free plasma PB level and CSF PB level was 112 ± 10.9%. 3) The amount of albumin filtering through in the 47 samples measured ranged from 0-100 mg/dl. The levels of free PB which passed through the Ultrafree Anticonvulsant Drug Filter were almost the same as the PB levels in CSF. This method enables the laboratory to prepare samples for free drug assays simply and efficiently.
Key words: Phenobarbital, free plasma PB, nonprotein bound PB, CSF PB, Ultrafree Anticonvulsant Drug Filter (Worthington).
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Clinical Evaluation of Phenobarbital (PB) and Phenytoin (PHT) Concentrations in Saliva in Epileptic Children Atsuko Yamaguchi, MD, Michiko Ishikawa, MD, Hiroe Kawade, MD, Mikiko Nakazato, MD, Susumu Itoh, MD, Tatsuya Ishikawa, MD, Kuniki Shimizu, MD, Atsuko A waya, MD, and Shoju Onishi, MD Department of Pediatrics, Medical School, Nagoya City University, Nagoya, Aichi (A Y, MI, HK, MN, SI, TI, KS, AA); Kagawa Medical School, Kagawa (SO)
Effect of the Time of Sampling on Serum Phenobarbital Concentration at Steady-State Kyoko Takizawa, MD, Hiroshi Shimizu, MD, liro Abe, MD, Yasuyuki Futagi, MD, Sachiko Onoe, MD, Hyakuji Yabuuchi, MD, and Atsushi Yamatodani, MD Pediatric Clinic, Ikeda City Hospital, Osaka (KT); Department of Pediatrics (HS, lA, YF, SO, HY) and 2nd Pharmacology (A Y), Osaka University, Medical School, Osaka
Previous reports on adult epileptics suggested the saliva concentration of anticonvulsantswas a better substitute for the serum or plasma concentration . The present study was undeI:taken to evaluate the clinical usefulness of the measurement of saliva concentrations of phenobarbital (PB) and phenytoin (PHT) in epileptic children by simultaneously measuring the concentrations in plasma and saliva samples.
Materials and Methods 140 paired samples of plasma and saliva were collected from 140 epileptic patients ranging in age from 6 months to 24 years. They were treated with PB alone, PHT alone, or PB and PHT. Patients with renal and/or liver disease were excluded. Saliva samples were collected 30 min after cleaning of the mouth with water. Saliva pH was measured with a micro pH meter. Concentrations of PB and PHT were measured by high pressure liquid chromatography. Saliva concentrations of PB were corrected for the pH of each saliva sample. Results and Discussion Saliva concentrations of PB were well correlated with plasma concentrations in patients on PB alone, and on PB and PHT (r = 0.93 and r = 0.82, respectively, p < 0.005). The ratios of saliva to plasma concentrations in these 2 groups of patients were 0.40 ± 0.19 and 0.39 ± 0.13, respectively. However, saliva concentrations of PB corrected for pH were not well correlated with plasma concentrations (r = 0.78 in patients on PB alone and r = 0.78 in those on PB and PHT). The reason for the poor correlation after correction for pH remains unknown at present, but the rapid change of pH in the smaller volume of samples obtained in infants and younger children might be a possible explanation. PHT concentrations in saliva were poorly correlated with plasma concentrations. Erroneously high concentrations were found in 7 out of 91. Residual administered PHT in the oral cavity after insufficient cleaning might cause these erratic data for saliva PHT concentration. Key words: Phenobarbital, phenytoin, saliva concen· tration.
Though phenobarbital (PB) is now widely used, very little is known as to when is the best time to obtain sample sera to evaluate the blood level of PB. We obtained serum samples before and after PB medication and tried to evaluate which sample gives the true blood level in different age groups, that is, which sample can be used as a b etter monitor of the serum PB concentration at steady-state.
Materials and Methods 203 children between 6 months to 16 years of age were involved in the study: 164 patients with epilepsy, 39 patients with febrile convulsion. These children had been on constant 2 daily doses of PB alone for at least 3 months. Blood samples were taken at 1-5 hours (the postdosing time) and at 13-15 hours (the predosing time) after the dose and quantitative determination of PB was carried out by heterogenous EIA. A total of 223 assays of PB were performed. The children were divided into 4 different age groups. Postdosing sampling group : Group a, 6 months to 3 years, 65 cases; Group b, 4-6 years, 81 cases; Group c, 7-10 years, 75 cases; Group d, 11-16 years, 38 cases. Predosing sampling group : Group A, 6 months to 3 years, 29 cases; Group B, 4-6 years, 20 cases; Group C, 7-10 years, 23 cases; Group D, 11-16 years, 21 cases. Results There was a good correlation between dose (D, mg/kg/ day) and serum PB level (S, ~g/ml) in each group. The mean SID ratio ± SD in each group was as follows : Group a, 4.9 ± 1.70; Group b, 5.0 ± 1.88; Group c, 5.9 ± 1.91 ; Group d, 6.1 ± 2.25 ; Group A, 3.8 ± 0.93; Group B, 4.1 ± 0.83; Group C, 5.0 ± 1.34 ; Group D, 6.3 ± 2.55 . In the groups under age 10, the SID ratio for the postdosing time was significantly higher than for the predosing time. In the groups above age 11, there were no significant differences of the SID ratio between post- and predosing. For postdosing there was a wide range of SID with advance in age and no . relationship was shown between SID and age, but for predosing there was a good correlation. Conclusion The determination of serum PB level was performed at 2 different sampling times-predosing and postdosing -from patients on doses in steady-state. According to our data the serum PB level at the predosing time was more effective for evaluating the PB dosing regimen, especially in children under age 10 whose pharmacokinetics seemed to be different from those of older children. Key words: Serum PB level, sampling time, SiD.
Brain & Development. Vol 4. No 3-4,1982- 263
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Effect of Sulfaphenazole on the Metabolism of Phenytoin Hideaki Ishikawa, MD, Kuniaki Narisawa, MD, Keiya Tada, MD, and Akiko Mue, MD Department of Pediatrics, Tohoku University, School of Medicine, Sendai, Miyagi (HI, KN, KT); National Nishitaga Hospital, Sendai, Miyagi (AM)
Serum High Density Lipoprotein Cholesterol Levels in Epileptic Children Treated with Anticonvulsants Hideharu Kawamura, MD, Masaki Hayashi, MD, Masayoshi Kin, MD, Osamu Matsuoka, MD, and Ryosuke Murata, MD Department of Pediatrics, Osaka Rosai Hospital, Sakai, Osaka (HK, MH); Department of Pediatrics, Osaka City University , M edical School, Osaka (MK, OM, RM)
Serum phenytoin levels were determined by the GLC technique in 15 epileptic patients, aged 9 to 26 years, taking usual doses of phenytoin for more than 5 years. The levels of phenytoin rose about 3-fold 7 to 10 days after adding sulfaphenazole (50 mg/kg daily). In order to investigate the disappearance curve of serum phenytoin, "C-phenytoin was injected intravenously into rats. From this experiment it was found that the disappearance rate of "C-phenytoin was markedly prolonged in 2 rats pretreated with sulfaphenazole (1,000 mg/kg daily) for 3 days before the experiment, as compared with 3 control rats. The half-life of 14C-phenytoin was about 90 minutes in control rats while that in sulfaphenazole pretreated rats was more than 240 minutes. When the preparation of rat liver microsomes was used in vitro, parahydroxylation of 14C-phenytoin was inhibited by 44% in the presence of 1 mM sulfaphenazole. These findings suggest that sulfaphenazole inhibits the activity of the enzyme hydroxylating phenytoin and may cause the increase of serum phenytoin levels. Consequently sulfaphenazole should be carefully given to epileptic patients taking usual doses of phenytoin.
Key words: Phenytoin, sulfaphenazole, parahydroxylation of phenytoin.
Recent reports described that the serum high density lipoprotein (HDL) cholesterol level is raised by some agents which also act as liver microsomal inducers. Phenytoin, known as a microsomal inducer and frequently used as an anticonvulsant, has been shown to increase the serum HDL cholesterol level in man. We determined serum HDL cholesterol levels in children treated ' with phenytoin, phenobarbital, and sodium valproate to confirm the above reports.
Materials and Methods 144 patients with epilepsy, and, as healthy controls, 60 convalescent patients with acute nephritis were studied . The average a ge of the patients was 8.4 ± 4.2 years, and that of the controls was 7.1 ± 3.8 years. Epileptic patients were divided into the following 3 groups. 1) Phenobarbital (PB) group, 60 cases, given PB only or PB with other anticonvulsants except phenytoin and/or sodium valproate. 2) Phenytoin (PHT) group, 60 cases, given PHT only or PHT with other anticonvulsants. 3) Sodium valproate (VPA) group, 22 cases, given VPA only or VPA with other anticonvulsants except PHT. Results In the PB group, total cholesterol was 170.2 ± 33 .5 mg/dl, HDL cholesterol was 61.4 ± 13.0 mg/dl, and the HDL.C/T.C r atio was 0.37 ± 0.09. In the PHT group, total cholesterol was 171 .5 ± 32.9 mg/dl, HDL cholesterol was 67 .1 ± 17.7 mg/dl, and the HDL.C/T.C ratio was 0.40 ± 0.10. In the VPA group, total cholesterol was 162.3 ± 31.1 mg/dl, HDL cholesterol was 65.2 ± 16.3 mg/dl, and the HDL.C/T.C ratio was 0.41 ± 0.09. In the controls, total cholesterol was 176.8 ± 37.4 mg/dl, HDL cholesterol was 57.1 ± 15.5 mg/dl, and the HDL.C/T.C ratio was 0.33 ± 0.10. Conclusion In comparison with healthy controls, these 3 groups showed no significant differences of total cholesterol levels. The PHT group gave a higher HDL cholesterol level and HDL.C/T.C ratio than controls (p < 0.01). In the VP A group, the HDL.C/T.C ratio was increased as compared to controls (p < 0.01). Key words: HDL cholesterol, phenytoin, phenobarbital, sodium valproate.
264 Brain & Development, Vol 4, No 3-4, 1982
119 Changes of Plasma Enzyme Activities in Epileptic Children during Anticonvulsive Therapy Masaharu Ohfu, MD, Tomoko Uchida, MD, Hiroko Ogata, MD, and Akihisa Mitsudome, MD Department of Pediatrics, School of Medicine, Fukuaka University, Fukuoka This study included 401 epileptic children treated with anticonvulsants, 215 males and 186 females, between 0 and 16 years of age. In these patients, plasma enzyme activities (GOT, GPT, LDH, ALP and -y-GTP) were tested. In 161 cases, the serum levels of phenobarbital (PB), phenytoin (PHT), sodium valproate (VP A) and carbamazepine (CBZ) were assayed. 1) The incidence of abnormalities was seen for -y-GTP (16.2%), LAP (3.6 %) and ALP (1.7%). 2) Abnormal values for -y-GTP were frequently seen in 31.5% of cases treated with multiple medication compared to in 3.2% of cases treated with a single medication. 3) Although the high level of -y-GTP was increased depending on the duration of multiple medication, there was no significant change in other serum enzymes. 4) There was no correlation between the serum concentrations of anticonvulsive drugs (pB, PHT, VPA and CBZ) and the serum enzymes. We observed that the incidence of high values for serum enzymes was seen in the level of -y-GTP in epileptic children treated with anticonvulsants and the abnormality of -y-GTP was correlated to the combination and the duration of medication.
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Shock Induced by Carbamazepine (Tegretol)
Yoshiyuki Honda, MD Department of Pediatrics, Katta Public Hospital, Shiraishi, Miyagi A 9-year-old male with epilepsy (sequela of encephalitis) received carbamazepine (Tegretol) treatment. Two days later high fever developed. But the treatment was continued because the patient had had lowgrade fever before starting the treatment. Eight days later the treatment induced exanthema that turned the entire body red , and so was stopped. As the patient continued to have epileptic attacks and other sequelae of encephalities, a month later carbamazepine (Tegretol) treatment was retried and it caused anaphylactic shock with a pruritic rash over the entire body and high fever which improved without serious sequelae after 2 days.
Key words: Carbamazepine (Tegretol), shock.
Key words: Side effects of anticonvulsants, -y-GTP, LAP, alkaline phosphatase.
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A Case of Hypoplastic Anemia Occurring after Administration of Sodium Valproate Yoshitaka Ishida, PhD, Naoki Shim%, MD, Mari Hoshi, MD, Seiko Ajiro, MD, Mariko Fujitsuka, MD, Tatsuya Hayashi, MD, Motoo Hayashi, PhD, Yoshiaki Kida, MD, and Hiroshi Maruyama, PhD Departments of Pediatrics (YI, NS, MH, SA, MF, TH, MH) and Neonatology (YK), Matsudo Municipal Hospital, Matsudo, Chiba; Matsudo Clinic, Matsudo, Chiba (HM) This is a report of a case of hypoplastic anemia which occurred after administration of sodium valproate. Thrombocytopenia has been reported after administration of sodium valproate but there is only one other case beside ours that showed pancytopenia associated with the use of sodium valproate . The other case was reported by Smith whose case exhibited bone marrow suppression after taking sodium valproate. Our patient was a small-for-date infant with the complication of anoxic encephalopathy. He was admitted to the Department of Neonatology (NICU), Matsudo Municipal Hospital, and was treated for intracerebral hemorrhage. He had a normal complete blood count 47 days after birth. An EEG recording 49 days after birth revealed multiple spikes and waves and sodium valproate treatment was started. The dose was 2 ml/day initially but was increased to 4 ml/day two weeks later. At 2.5 months of age, he was admitted to the Dept of Pediatrics because of apnea due to a pertussis infection. Findings on admission revealed numerous petechiae, significant anemia and pancytopenia (Hb 6.6/dl, RBCs 208 x 10., WBCs 3,100 platelets 2.6 x 10'). Bone marrow aspiration revealed suppression of all bone marrow elements. Blood transfusion and administration of steroids did not bring about clinical improvement nor a satisfactory response of the depressed complete blood count. On the 111 th day after birth sodium valproate administration was discontinued after the blood count was observed. On the 134th day after birth, the patient was discharged. He is doing well at the time of writing this report. The findings of bone marrow suppression as demonstrated by the serial changes in the hemogram and bone marrow aspiration, occurred subsequent to the administration of sodium valproate. Thrombocytopenia has often been reported as an important side effect of this drug. Our experience indicates that severe bone marrow suppression may be another important hematologic side effect. Complete blood counts should be closely monitored in all children receiving sodium valproate.
MD Department of Pediatrics, Kansai Medical University, Osaka (TS, A Y, KH); Taniuchi Children 's Hospital, Osaka (YS, KT) Hyperglycinemia is known to occur in patients treated with sodium valproate (VPA) as an anticonvulsant. Recently, hyperammonemic encephalopathy in a patient taking VP A was reported (Coulter & Allen, 1980). We have also observed hyperammonemia in 9 patients taking VP A during the past 1.5 years.
Materials and Methods For 90 patients, ranging from 9 months to 14 years old, taking various anticonvulsants (30% were treated with VPA), blood ammonia, serum VPA level, serum amino acids, urine oro tate and liver functions were examined three times a year as routine examinations and additionally whenever the subjects developed repeated convulsions, and impaired consciousness. The blood ammonia level was determined by using the "Amitest" as previously described (Tada et ai, 1979). Serum VP A was assayed by gas chromatography. The serum amino acids were analyzed by high performance liquid chromatography. Results Hyperammonemia (from 75 ILg/dl to 250 ILg/dl) was found in 9 out of the 90 subjects. All of these 9 hyperammonemic patients had been treated with VP A. They also exhibited hyperglycinemia, while the other group which was not treated with VP A showed normal s-glycine levels (mean: 4181Lmol/1 vs 267 ).Imol/I). VPA serum concentrations ranged from 281Lg/ml to 135 ILg/ ml (mean 68.5 ).Ig/ml) in these patients, and VPA medication ranged from 16 mg/kg/day to 40 mg/kg/day (mean 23.8 mg/kg/day). The correlation between the values of blood ammonia and (1) s-VPA concentrations, (2) s-glycine level as well as (3) the dose of VPA medication was not significant. During the hyperammonemic episodes, 6 of the 9 hyperammonemic patients developed somnolence, clumsiness, hypotonia and poor manipulation. These symptoms were gradually relieved by drip infusion treatment, and the high ammonia level was reduced to within normal limits. Orotate level in the urine and liver functions during hyperammonemia were within normal limits.
Key words: Hypoplastic anemia, valproic acid, side effect of anticonvulsant.
Discussion It is likely that hyperammonemia in patients taking VPA is induced by the increased level of propionyl Co-A. Because this propionyl Co-A inhibits N-acetylglutamate synthetase which activates carbamylphosphate synthetase (CPS), the reduced CPS activity causes hyperammonemia. When catabolism was accelerated by infections and convulsions as sometimes observed in patients treated with VPA, the reduced CPS activity may be manifested as significant hyperammonemia.
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Conclusion Blood ammonia levels should be monitored periodically while using VP A, especially when the consciousness of the patients becomes impaired.
Sodium Valproate (VP A) and Hyperammonemia Tateo Sugimoto, MD, Akihiro Yasuhara, MD, Katsuko Hara, MT, Y oshimi Sakane, MT, and Kiyoshi Taniuchi,
Key words: Hyperammonemia, sodium valproate, hyperglycinemia, oro ta te.
266 Brain & Development, Vol 4, No 3-4, 1982
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Relative Bioavailability of Two Different Phenytoin Pharmaceutical Formulas- Especially in Relation to Age-
Antiepileptic Effects of Clobazam in Children
Makoto Matsukura, MD, Tetsuo Ikeda, MD, Akimasa Higashi, MD, and Jchiro Matsuda, MD Department of Pediatrics, Kumamoto University, School of Medicine, Kumamoto Patients with epilepsy treated with phenytoin were classified into three groups depending on age, group I (0-5 yrs), group II (6-10 yrs) and group III (above 11 yrs). Studies are done at steady-state phase of phenytoin treatment by oral administration. The Vmax/F of Aleviatin® (Dainippon Co Ltd) powder and Hydantol® (Fujinaga Co Ltd) 25 mg tablet in each group is calculated from the following equation: F. D= Vmax·L Krn + L L/D=~+ __l_.L Vmax/F Vmax/F
F : Fraction of absorbed drug, D: dose (mg/kg·day), L: serum level of phenytoin, Vmax and Krn: MichaelisMenten kinetic parameters. In each age group , regression analysis is used to calculate the averaged values of Vmax/F of two different phenytoin pharmaceutical formula s. Percent of Vmax/F of Aleviatin® to Hydantol® are 65% (group I), 74% (group II) and 78% (group III). Based on the assumption that average Vmax is not different among two subgroups of same age group, who administer Aleviatin® or Hydantol®, it might be concluded that percent of absorbed dose of Aleviatin® is much less than that of Hydantol® in infants, compared with aged children and adults.
Key words: Bioavailability, phenytoin, serum con· centration.
Hiroshi Shimizu, MD, lira Abe, MD, Yasuyuki Futagi, MD, Sachiko Onoe, MD, Tatsuzo Tagawa, MD, Takashi Mimaki, MD, Hyakuji Yabuuchi, MD, Mori· fusa Kamio, MD, Kiyoomi Sumi, MD, Takahiro Sugita, MD, Atsushi Yamatodani, MD, and Masahiro Kato, MD Department of Pediatrics (HS, lA, YF, SO, TT, TM, HY, MK, KS, TS) and 2nd Pharmacology (A Y), Osaka University , Medical School, Osaka; Department of Pediatrics, Kansai Rosai Hospital, Amagasaki, Hyogo (MK) Many benzodiazepines used as anticonvulsants have nitrogen radicals in positions 1 and 4. Clobazam has nitrogen radicals in positions 1 and 5. We studied clobazam as antiepileptics in 36 patients with intractable epilepsies in childhood. Their ages were 1 year 1 month to 16 years 5 months (mean, 8 years). The types of epilepsies were primary generalized epilepsy (2 cases), secondary generalized epilepsy (29 cases) and partial epilepsy (5 cases). The patients were started on daily doses of 0.33 mg/kg and the dosage was increased to 0.71 mg/kg. Nine cases (primary generalized epilepsy 2/2, secondary generalized epilepsy 7/29) of the patients were completely free from seizures, and another 9 cases (secondary generalized epilepsy 8/29, partial epilepsy 1/5) experienced a decrease of 50% or more in seizure frequency. Sixteen cases did not change, and 2 cases (secondary generalized epilepsy 2/29) worsened. We observed the antiepileptic effects on the first day to 10th day after clobazam treatment. Four cases out of 9 patients who were completely free from seizures reappeared, the effects in 3 cases lasted for only a month and in 1 case it lasted for 10 months. Mean serum clobazam level of 7 effective cases was 73 ng/ml and that of noneffective cases was 94 ng/m!. Although we observed mild and transient clinical side effects such as drowsiness in 17 cases, no patients showed abnormality of laboratory findings.
Key words: Clobazam, epilepsy, serum level.
260 Brain & Development, Vol 4, No 3-4,1982
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Effects of Antiepileptic Drugs on Benzodiazepine Receptors in Rat Brain
Clinical Pharmacokinetics of Nitrazepam Using High-Pressure Liquid Chromatography
Takashi Mimaki, MD, Henry 1. Yamamura, PhD, and Hyakuji Yabuuchi, MD Department of Pediatrics, Osaka University, Medical School, Osaka (TM, HY); Department of Pharmacology, University of Arizona, Tucson, USA (H!Y) Benzodiazepine receptors appear to possess a variety of pharmacologic actions on the mammalian central nervous system including anxiolytic, hypnotic, anticonvulsant and muscle relaxant activities. In the present investigation, we determined the effects of acute administration of valproic acid (Vp A), aminooxyacetic acid (AOAA), phenytoin (PHT), phenobarbital (PB) and diazepam (DZP) on specific 3H-f1unitrazepam binding in rat cerebral cortices.
Materials and Methods In these experiments, male Sprague-Dawley rats (about 200 g body weight) were used as experimental animals. Animals received a single ip injection of VP A (100-500 mg/kg), AOAA (50 mg/kg), PHT (100200 mg/kg), PB (50 mg/kg), DZP (50 mg/kg) or 1 ml/kg of control vehicle, and were sacrificed one hour after injection. 3H-f1unitrazepam binding was determined by filter binding assay. Results In VPA (100 mg/kg) treated rats, there was a 11.3 % increase in benzodiazepine receptor density (Bmax). This effect appeared to be dose-dependent as higher doses of VPA (200-500 mg/kg) resulted in a greater increase in Bmax. No change in dissociation constant (Kd) occurred after pretreatment of animals with varying doses of VPA. On the other hand, AOAA (50 mg/kg) treated rats showed a 34.3 % increase in Bmax with a significant decrease in Kd. However, acute administration of PHT (100-200 mg/kg), PB (50 mg/kg) or DZP (50 mg/kg) did not produce any changes in either Bmax or Kd. Additional experiments indicate that VPA or PB has no effects in vitro on specific 3H-flunitrazepam binding. On the other hand, we observed a competitive inhibitory effect of PHT on specific 3H_ f1unitrazepam binding in vitro. In the cerebral cortex, 100/.lM of PHT caused a 32% decrease in specific 3H-f1unitrazepam binding. Conclusions 1) Acute VPA administration produced a dosedependent increase in 3H-f1unitrazepam binding (Bmax) in rat cerebral cortex. 2) Acute AOAA administration resulted in a significant increase in Bmax with a significant decrease in Kd. 3) No significant changes occurred in either Bmax or Kd after acute PHT, PB or DZP administration. 4) PHT inhibits specific 3H-f1unitrazepam binding competitively in vitro. 5) Alterations in benzodiazepine receptor binding in rat brain may correlate with the mechanism of anticonvulsant action of VP A, AOAA and PHT.
Yukihiko Katafuchi, MD, Nobuyuki Aoki, MD, Eiji Yano , MD, Toyojiro Matsuishi, MD, Fumio Yamashita, MD, and Hiroyuki Haraguchi, MD Department of Pediatrics and Child Health , Kurume University , School of Medicine, Kurume, Fukuoka (YK, NA, EY, TM, FY); Department of Pediatrics, The Center of Developmental Medicine and Education of Kitakyushu City, Kitakyushu , Fukuoka (HH) Serum levels of nitrazepam (NZP) in 60 epileptic children ranging in age from 6 months to 18 years were investigated by high-pressure liquid chromatography and the influence of age and phenobarbital (PB) or sodium valproate (VPA) on the serum NZP level were studied. Moreover, in 9 patients (NZP alone, 2 cases; NZP with PB, 3 cases; NZP with VPA, 4 cases), serum half-lives of nitrazepam were also calculated.
Materials and Methods Sixty epileptic children included 30 cases with severe handicaps without any change in the prescription for at least the last 1 month were selected for our study. Blood sampling for the determination of serum NZP level was performed 3 hours after the morning dose. In 9 patients for the calculation of nitrazepam halflives, blood sampling was performed 10, 12, 14 and 16 hours after the last night dose (the morning dose was omitted). Our method - Simultaneous highpressure liquid chromatographic determination of 5 antiepileptic drugs in serum was carried out for this study. Conclusion The following conclusions were made. 1) The serum nitrazepam level was well correlated with the daily dose in 60 epileptic children with a correlation coefficient of 0.683 (p < 0.01). 2) The 60 patients were divided into 3 groups comprising 13 treated with NZP alone, 24 with NZP + PB and 23 with NZP + VPA, and the coefficients of correlation between serum level and dose were 0.955 (p < 0.01), 0.968 (p < 0.001) and 0.959 (p < 0.001), respectively. Treatment with NZP + PB showed a significantly higher serum level than that with NZP alone and that with NZP + VPA showed a lower level. 3) Divided into 3 groups according to age, the regression lines were much the same, although no significant correlation coefficient was obtained. 4) Serum half-lives of nitrazepam were significantly different in the 3 groups (NZP alone, 10.2 ± 0.3 hours; NZP + PB, 25 .6 ± 4.9 hours; NZP + VPA, 6.3 ± 1.2 hours). Key words: Nitrazepam, clinical pharmacokinetics, high-pressure liquid chromatography.
Key words: Benzodiazepine receptors, antiepileptic drugs, !lunitrazepam.
Brain & Development, Vol 4, No 3-4, 1982 261
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Plasma Levels of Valproic Acid and Its Metabolism in Neonatal Convulsions: Application of a GLC-Micromethod
A simple Method using Ultrafiltration Membranes to Measure Free Antiepileptic Drug Concentrations
Nobuo Koide, MD, Yukinao Take be, MD, Satoshi Haneda, MD, and fun Watanabe, MD Department of Pediatrics, Hirosaki University, School of Medicine, Hirosaki, Aomori The microdetermination method for plasma valproic acid (VPA) by gas liquid chromatography (GLCmicromethod) requiring only 50/.11 of plasma samples drawn from the heel or auricle was first modified by the authors. The values for plasma VPA determined by the GLC-micromethod were compared with those by the ordinary GLC-method (GLC) and by the homogeneous enzyme immunoassay (EMIT). Plasma VPA levels in 8 cases with neonatal convulsions were chronologically investigated using the GLC-micromethod.
Methods Capillary blood samples in 2 Hct tubes were centrifuged for 5 minutes at 10,000 rpm. Fifty microliters of plasma samples was vigorously mixed for 30 seconds with 150/.11 of 10% TCA and 200/.11 of diphenylchloroform (5 /.Ig/ml). After centrifugation, about 3 /.II of the organic phase was prepared for the GLC-micromethod. Results The same blood samples were used for determinations by three different methods, i.e., the GLC-micromethod, GLC and EMIT. The correlation between the values by each pair of methods was excellent (p < 0.001) ranging from 0 to 187 /.Ig/ml in 30 cases' (n = 30) in total. The correlation between the values for capillary blood by the GLC-micromethod (P) and those for venous blood by GLC (V) was as follows (n = 50). Both blood samples were collected at the same time. P = 1.01 V - 0.99 (r = 0.98, p < 0.001). In 16 cases of from 1 day to 24 months of age, the correlation between the values determined by the above 2 methods was as follows. P = 1.01 V - 1.97 (r = 0.99, p < 0.001). Conclusion
1) VPA absorption was also good in the neonatal
period. 2) The half-life of VP A was long in the neonatal period, especially in infants of 1 to 2 weeks of age and in preterm infants. A few cases showed VPA accumulation in plasma, including a case with the highest value of 257 /.Ig/ml (Cmin) with a half-life at about 4 days. 3) Plasma VPA levels of 60-100/.lg/ml (Cmin) could be maintained with the dosage of 15-20 mg/kg/ day. 4) Repeated monitoring of plasma VP A levels is mandatory in the neonatal period. 5) The GLC-micromethod is satisfactory for clinical use because it is an accurate, less-invasive and timesaving procedure.
Key words: Valproic acid, gas liqUid chromatography, GLC-micromethod, neonatal convulsions.
262 Brain & Development, Vol 4, No 3-4,1982
Sonsu Lee, MD, Ryosuke Murata, MD, Osamu Matsuoka, MD, Masayoshi Kin, MD, Mayumi Tani, MD, Gen Isshiki, MD, and Yasuo Horiuchi, MD Department of Pediatrics, Osaka City University , Medical School, Osaka (SL, RM, OM, MK, MT, GI); Department of Pediatrics, Children's Medical Center of Osaka City, Osaka (YH) It is only nonprotein bound anticonvulsant drugs that
can produce the desired physiologic or therapeutic effects in epilepsy. Changes in patient health status, additional drug intake, individual peculiarities, or multiple drug therapies can alter the extent of drugprotein binding and thus affect the pharmacologically important nonprotein bound (free) drug level. We measured free phenobarbital (PB) levels in the plasma of epileptic children. Twenty plasma samples were freshly drawn and heparinized, and 56 had been drawn 1-2 weeks earlier and frozen. The samples were filtered through an Ultrafree Anticonvulsant Drug Filter (Worthington), each sample taking 45-90 minutes. The amount of albumin which passed through the filter membrane was measured on an ImmuneDiffuse Plate (Behring). Subsequently, PB levels of cerebrospinal fluid (CSF) were measured and compared to the plasma free levels. The PB levels were measured by the EMIT technique. The results were as follows: 1) The ratio of free plasma PB level and total plasma PB level (F%) was 54.8 ± 8.54% (mean ± SD) in 76 specimens. F% for 16 samples from patients treated with PB alone was 50.9 ± 5.68%. F% for 60 samples with both PB and other antiepileptic drugs was 55.8 ± 8.88%. F % for 12 samples with PB and sodium valproate was 61.1 ± 7.78%. 2) The ratio of free plasma PB level and CSF PB level was 112 ± 10.9%. 3) The amount of albumin filtering through in the 47 samples measured ranged from 0-100 mg/dl. The levels of free PB which passed through the Ultrafree Anticonvulsant Drug Filter were almost the same as the PB levels in CSF. This method enables the laboratory to prepare samples for free drug assays simply and efficiently.
Key words: Phenobarbital, free plasma PB, nonprotein bound PB, CSF PB, Ultrafree Anticonvulsant Drug Filter (Worthington).
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Clinical Evaluation of Phenobarbital (PB) and Phenytoin (PHT) Concentrations in Saliva in Epileptic Children Atsuko Yamaguchi, MD, Michiko Ishikawa, MD, Hiroe Kawade, MD, Mikiko Nakazato, MD, Susumu Itoh, MD, Tatsuya Ishikawa, MD, Kuniki Shimizu, MD, Atsuko A waya, MD, and Shoju Onishi, MD Department of Pediatrics, Medical School, Nagoya City University, Nagoya, Aichi (A Y, MI, HK, MN, SI, TI, KS, AA); Kagawa Medical School, Kagawa (SO)
Effect of the Time of Sampling on Serum Phenobarbital Concentration at Steady-State Kyoko Takizawa, MD, Hiroshi Shimizu, MD, liro Abe, MD, Yasuyuki Futagi, MD, Sachiko Onoe, MD, Hyakuji Yabuuchi, MD, and Atsushi Yamatodani, MD Pediatric Clinic, Ikeda City Hospital, Osaka (KT); Department of Pediatrics (HS, lA, YF, SO, HY) and 2nd Pharmacology (A Y), Osaka University, Medical School, Osaka
Previous reports on adult epileptics suggested the saliva concentration of anticonvulsantswas a better substitute for the serum or plasma concentration . The present study was undeI:taken to evaluate the clinical usefulness of the measurement of saliva concentrations of phenobarbital (PB) and phenytoin (PHT) in epileptic children by simultaneously measuring the concentrations in plasma and saliva samples.
Materials and Methods 140 paired samples of plasma and saliva were collected from 140 epileptic patients ranging in age from 6 months to 24 years. They were treated with PB alone, PHT alone, or PB and PHT. Patients with renal and/or liver disease were excluded. Saliva samples were collected 30 min after cleaning of the mouth with water. Saliva pH was measured with a micro pH meter. Concentrations of PB and PHT were measured by high pressure liquid chromatography. Saliva concentrations of PB were corrected for the pH of each saliva sample. Results and Discussion Saliva concentrations of PB were well correlated with plasma concentrations in patients on PB alone, and on PB and PHT (r = 0.93 and r = 0.82, respectively, p < 0.005). The ratios of saliva to plasma concentrations in these 2 groups of patients were 0.40 ± 0.19 and 0.39 ± 0.13, respectively. However, saliva concentrations of PB corrected for pH were not well correlated with plasma concentrations (r = 0.78 in patients on PB alone and r = 0.78 in those on PB and PHT). The reason for the poor correlation after correction for pH remains unknown at present, but the rapid change of pH in the smaller volume of samples obtained in infants and younger children might be a possible explanation. PHT concentrations in saliva were poorly correlated with plasma concentrations. Erroneously high concentrations were found in 7 out of 91. Residual administered PHT in the oral cavity after insufficient cleaning might cause these erratic data for saliva PHT concentration. Key words: Phenobarbital, phenytoin, saliva concen· tration.
Though phenobarbital (PB) is now widely used, very little is known as to when is the best time to obtain sample sera to evaluate the blood level of PB. We obtained serum samples before and after PB medication and tried to evaluate which sample gives the true blood level in different age groups, that is, which sample can be used as a b etter monitor of the serum PB concentration at steady-state.
Materials and Methods 203 children between 6 months to 16 years of age were involved in the study: 164 patients with epilepsy, 39 patients with febrile convulsion. These children had been on constant 2 daily doses of PB alone for at least 3 months. Blood samples were taken at 1-5 hours (the postdosing time) and at 13-15 hours (the predosing time) after the dose and quantitative determination of PB was carried out by heterogenous EIA. A total of 223 assays of PB were performed. The children were divided into 4 different age groups. Postdosing sampling group : Group a, 6 months to 3 years, 65 cases; Group b, 4-6 years, 81 cases; Group c, 7-10 years, 75 cases; Group d, 11-16 years, 38 cases. Predosing sampling group : Group A, 6 months to 3 years, 29 cases; Group B, 4-6 years, 20 cases; Group C, 7-10 years, 23 cases; Group D, 11-16 years, 21 cases. Results There was a good correlation between dose (D, mg/kg/ day) and serum PB level (S, ~g/ml) in each group. The mean SID ratio ± SD in each group was as follows : Group a, 4.9 ± 1.70; Group b, 5.0 ± 1.88; Group c, 5.9 ± 1.91 ; Group d, 6.1 ± 2.25 ; Group A, 3.8 ± 0.93; Group B, 4.1 ± 0.83; Group C, 5.0 ± 1.34 ; Group D, 6.3 ± 2.55 . In the groups under age 10, the SID ratio for the postdosing time was significantly higher than for the predosing time. In the groups above age 11, there were no significant differences of the SID ratio between post- and predosing. For postdosing there was a wide range of SID with advance in age and no . relationship was shown between SID and age, but for predosing there was a good correlation. Conclusion The determination of serum PB level was performed at 2 different sampling times-predosing and postdosing -from patients on doses in steady-state. According to our data the serum PB level at the predosing time was more effective for evaluating the PB dosing regimen, especially in children under age 10 whose pharmacokinetics seemed to be different from those of older children. Key words: Serum PB level, sampling time, SiD.
Brain & Development. Vol 4. No 3-4,1982- 263
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Effect of Sulfaphenazole on the Metabolism of Phenytoin Hideaki Ishikawa, MD, Kuniaki Narisawa, MD, Keiya Tada, MD, and Akiko Mue, MD Department of Pediatrics, Tohoku University, School of Medicine, Sendai, Miyagi (HI, KN, KT); National Nishitaga Hospital, Sendai, Miyagi (AM)
Serum High Density Lipoprotein Cholesterol Levels in Epileptic Children Treated with Anticonvulsants Hideharu Kawamura, MD, Masaki Hayashi, MD, Masayoshi Kin, MD, Osamu Matsuoka, MD, and Ryosuke Murata, MD Department of Pediatrics, Osaka Rosai Hospital, Sakai, Osaka (HK, MH); Department of Pediatrics, Osaka City University , M edical School, Osaka (MK, OM, RM)
Serum phenytoin levels were determined by the GLC technique in 15 epileptic patients, aged 9 to 26 years, taking usual doses of phenytoin for more than 5 years. The levels of phenytoin rose about 3-fold 7 to 10 days after adding sulfaphenazole (50 mg/kg daily). In order to investigate the disappearance curve of serum phenytoin, "C-phenytoin was injected intravenously into rats. From this experiment it was found that the disappearance rate of "C-phenytoin was markedly prolonged in 2 rats pretreated with sulfaphenazole (1,000 mg/kg daily) for 3 days before the experiment, as compared with 3 control rats. The half-life of 14C-phenytoin was about 90 minutes in control rats while that in sulfaphenazole pretreated rats was more than 240 minutes. When the preparation of rat liver microsomes was used in vitro, parahydroxylation of 14C-phenytoin was inhibited by 44% in the presence of 1 mM sulfaphenazole. These findings suggest that sulfaphenazole inhibits the activity of the enzyme hydroxylating phenytoin and may cause the increase of serum phenytoin levels. Consequently sulfaphenazole should be carefully given to epileptic patients taking usual doses of phenytoin.
Key words: Phenytoin, sulfaphenazole, parahydroxylation of phenytoin.
Recent reports described that the serum high density lipoprotein (HDL) cholesterol level is raised by some agents which also act as liver microsomal inducers. Phenytoin, known as a microsomal inducer and frequently used as an anticonvulsant, has been shown to increase the serum HDL cholesterol level in man. We determined serum HDL cholesterol levels in children treated ' with phenytoin, phenobarbital, and sodium valproate to confirm the above reports.
Materials and Methods 144 patients with epilepsy, and, as healthy controls, 60 convalescent patients with acute nephritis were studied . The average a ge of the patients was 8.4 ± 4.2 years, and that of the controls was 7.1 ± 3.8 years. Epileptic patients were divided into the following 3 groups. 1) Phenobarbital (PB) group, 60 cases, given PB only or PB with other anticonvulsants except phenytoin and/or sodium valproate. 2) Phenytoin (PHT) group, 60 cases, given PHT only or PHT with other anticonvulsants. 3) Sodium valproate (VPA) group, 22 cases, given VPA only or VPA with other anticonvulsants except PHT. Results In the PB group, total cholesterol was 170.2 ± 33 .5 mg/dl, HDL cholesterol was 61.4 ± 13.0 mg/dl, and the HDL.C/T.C r atio was 0.37 ± 0.09. In the PHT group, total cholesterol was 171 .5 ± 32.9 mg/dl, HDL cholesterol was 67 .1 ± 17.7 mg/dl, and the HDL.C/T.C ratio was 0.40 ± 0.10. In the VPA group, total cholesterol was 162.3 ± 31.1 mg/dl, HDL cholesterol was 65.2 ± 16.3 mg/dl, and the HDL.C/T.C ratio was 0.41 ± 0.09. In the controls, total cholesterol was 176.8 ± 37.4 mg/dl, HDL cholesterol was 57.1 ± 15.5 mg/dl, and the HDL.C/T.C ratio was 0.33 ± 0.10. Conclusion In comparison with healthy controls, these 3 groups showed no significant differences of total cholesterol levels. The PHT group gave a higher HDL cholesterol level and HDL.C/T.C ratio than controls (p < 0.01). In the VP A group, the HDL.C/T.C ratio was increased as compared to controls (p < 0.01). Key words: HDL cholesterol, phenytoin, phenobarbital, sodium valproate.
264 Brain & Development, Vol 4, No 3-4, 1982
119 Changes of Plasma Enzyme Activities in Epileptic Children during Anticonvulsive Therapy Masaharu Ohfu, MD, Tomoko Uchida, MD, Hiroko Ogata, MD, and Akihisa Mitsudome, MD Department of Pediatrics, School of Medicine, Fukuaka University, Fukuoka This study included 401 epileptic children treated with anticonvulsants, 215 males and 186 females, between 0 and 16 years of age. In these patients, plasma enzyme activities (GOT, GPT, LDH, ALP and -y-GTP) were tested. In 161 cases, the serum levels of phenobarbital (PB), phenytoin (PHT), sodium valproate (VP A) and carbamazepine (CBZ) were assayed. 1) The incidence of abnormalities was seen for -y-GTP (16.2%), LAP (3.6 %) and ALP (1.7%). 2) Abnormal values for -y-GTP were frequently seen in 31.5% of cases treated with multiple medication compared to in 3.2% of cases treated with a single medication. 3) Although the high level of -y-GTP was increased depending on the duration of multiple medication, there was no significant change in other serum enzymes. 4) There was no correlation between the serum concentrations of anticonvulsive drugs (pB, PHT, VPA and CBZ) and the serum enzymes. We observed that the incidence of high values for serum enzymes was seen in the level of -y-GTP in epileptic children treated with anticonvulsants and the abnormality of -y-GTP was correlated to the combination and the duration of medication.
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Shock Induced by Carbamazepine (Tegretol)
Yoshiyuki Honda, MD Department of Pediatrics, Katta Public Hospital, Shiraishi, Miyagi A 9-year-old male with epilepsy (sequela of encephalitis) received carbamazepine (Tegretol) treatment. Two days later high fever developed. But the treatment was continued because the patient had had lowgrade fever before starting the treatment. Eight days later the treatment induced exanthema that turned the entire body red , and so was stopped. As the patient continued to have epileptic attacks and other sequelae of encephalities, a month later carbamazepine (Tegretol) treatment was retried and it caused anaphylactic shock with a pruritic rash over the entire body and high fever which improved without serious sequelae after 2 days.
Key words: Carbamazepine (Tegretol), shock.
Key words: Side effects of anticonvulsants, -y-GTP, LAP, alkaline phosphatase.
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A Case of Hypoplastic Anemia Occurring after Administration of Sodium Valproate Yoshitaka Ishida, PhD, Naoki Shim%, MD, Mari Hoshi, MD, Seiko Ajiro, MD, Mariko Fujitsuka, MD, Tatsuya Hayashi, MD, Motoo Hayashi, PhD, Yoshiaki Kida, MD, and Hiroshi Maruyama, PhD Departments of Pediatrics (YI, NS, MH, SA, MF, TH, MH) and Neonatology (YK), Matsudo Municipal Hospital, Matsudo, Chiba; Matsudo Clinic, Matsudo, Chiba (HM) This is a report of a case of hypoplastic anemia which occurred after administration of sodium valproate. Thrombocytopenia has been reported after administration of sodium valproate but there is only one other case beside ours that showed pancytopenia associated with the use of sodium valproate . The other case was reported by Smith whose case exhibited bone marrow suppression after taking sodium valproate. Our patient was a small-for-date infant with the complication of anoxic encephalopathy. He was admitted to the Department of Neonatology (NICU), Matsudo Municipal Hospital, and was treated for intracerebral hemorrhage. He had a normal complete blood count 47 days after birth. An EEG recording 49 days after birth revealed multiple spikes and waves and sodium valproate treatment was started. The dose was 2 ml/day initially but was increased to 4 ml/day two weeks later. At 2.5 months of age, he was admitted to the Dept of Pediatrics because of apnea due to a pertussis infection. Findings on admission revealed numerous petechiae, significant anemia and pancytopenia (Hb 6.6/dl, RBCs 208 x 10., WBCs 3,100 platelets 2.6 x 10'). Bone marrow aspiration revealed suppression of all bone marrow elements. Blood transfusion and administration of steroids did not bring about clinical improvement nor a satisfactory response of the depressed complete blood count. On the 111 th day after birth sodium valproate administration was discontinued after the blood count was observed. On the 134th day after birth, the patient was discharged. He is doing well at the time of writing this report. The findings of bone marrow suppression as demonstrated by the serial changes in the hemogram and bone marrow aspiration, occurred subsequent to the administration of sodium valproate. Thrombocytopenia has often been reported as an important side effect of this drug. Our experience indicates that severe bone marrow suppression may be another important hematologic side effect. Complete blood counts should be closely monitored in all children receiving sodium valproate.
MD Department of Pediatrics, Kansai Medical University, Osaka (TS, A Y, KH); Taniuchi Children 's Hospital, Osaka (YS, KT) Hyperglycinemia is known to occur in patients treated with sodium valproate (VPA) as an anticonvulsant. Recently, hyperammonemic encephalopathy in a patient taking VP A was reported (Coulter & Allen, 1980). We have also observed hyperammonemia in 9 patients taking VP A during the past 1.5 years.
Materials and Methods For 90 patients, ranging from 9 months to 14 years old, taking various anticonvulsants (30% were treated with VPA), blood ammonia, serum VPA level, serum amino acids, urine oro tate and liver functions were examined three times a year as routine examinations and additionally whenever the subjects developed repeated convulsions, and impaired consciousness. The blood ammonia level was determined by using the "Amitest" as previously described (Tada et ai, 1979). Serum VP A was assayed by gas chromatography. The serum amino acids were analyzed by high performance liquid chromatography. Results Hyperammonemia (from 75 ILg/dl to 250 ILg/dl) was found in 9 out of the 90 subjects. All of these 9 hyperammonemic patients had been treated with VP A. They also exhibited hyperglycinemia, while the other group which was not treated with VP A showed normal s-glycine levels (mean: 4181Lmol/1 vs 267 ).Imol/I). VPA serum concentrations ranged from 281Lg/ml to 135 ILg/ ml (mean 68.5 ).Ig/ml) in these patients, and VPA medication ranged from 16 mg/kg/day to 40 mg/kg/day (mean 23.8 mg/kg/day). The correlation between the values of blood ammonia and (1) s-VPA concentrations, (2) s-glycine level as well as (3) the dose of VPA medication was not significant. During the hyperammonemic episodes, 6 of the 9 hyperammonemic patients developed somnolence, clumsiness, hypotonia and poor manipulation. These symptoms were gradually relieved by drip infusion treatment, and the high ammonia level was reduced to within normal limits. Orotate level in the urine and liver functions during hyperammonemia were within normal limits.
Key words: Hypoplastic anemia, valproic acid, side effect of anticonvulsant.
Discussion It is likely that hyperammonemia in patients taking VPA is induced by the increased level of propionyl Co-A. Because this propionyl Co-A inhibits N-acetylglutamate synthetase which activates carbamylphosphate synthetase (CPS), the reduced CPS activity causes hyperammonemia. When catabolism was accelerated by infections and convulsions as sometimes observed in patients treated with VPA, the reduced CPS activity may be manifested as significant hyperammonemia.
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Conclusion Blood ammonia levels should be monitored periodically while using VP A, especially when the consciousness of the patients becomes impaired.
Sodium Valproate (VP A) and Hyperammonemia Tateo Sugimoto, MD, Akihiro Yasuhara, MD, Katsuko Hara, MT, Y oshimi Sakane, MT, and Kiyoshi Taniuchi,
Key words: Hyperammonemia, sodium valproate, hyperglycinemia, oro ta te.
266 Brain & Development, Vol 4, No 3-4, 1982