The necessity of adjusting the dosage of zonisamide when coadministered with other anti-epileptic drugs

Masahiko Shinoda, Masahiro Akita, Masaya Hasegawa, Takaaki Hasegawa, Toshitaka Nabeshima

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

Zonisamide (ZNS), a new anti-epileptic drug that exhibits a wide anti- epileptic spectrum, is commonly prescribed concomitantly with other anti- epileptic drugs. The interaction between ZNS and other anti-epileptic drugs was investigated in epileptic patients. The steady state plasma levels of all the anti-epileptic drugs were measured by high-performance liquid chromatography. The concomitant administration of phenobarbital (PB), phenytoin (PHT), or carbamazepine (CBZ) with ZNS significantly decreased the ratio of the steady state plasma concentration to the administered dose (C/D ratio) of ZNS, whereas clonazepam (CZP) and valproic acid (VPA) when administered concomitantly with ZNS did not change the C/D ratio. Significant negative correlations were observed between the C/D ratio of ZNS and the doses of PB, PHT, CBZ, and VPA. On the other hand, the ratio of the plasma concentration of carbamazepine-10,11-epoxide (CBZ-E), the major active metabolite of CBZ, to the plasma concentration of CBZ was significantly decreased by concomitant administration with ZNS, indicating that ZNS inhibits the metabolism of CBZ. These findings show that when ZNS is administered concomitantly with these anti-epileptic drugs, it is necessary to monitor the plasma concentration of ZNS in order to adjust its dosage.

Original languageEnglish
Pages (from-to)1090-1092
Number of pages3
JournalBiological and Pharmaceutical Bulletin
Volume19
Issue number8
DOIs
Publication statusPublished - 01-01-1996
Externally publishedYes

Fingerprint

zonisamide
Carbamazepine
Pharmaceutical Preparations
Valproic Acid
Phenytoin
Phenobarbital
Clonazepam

All Science Journal Classification (ASJC) codes

  • Pharmacology
  • Pharmaceutical Science

Cite this

Shinoda, Masahiko ; Akita, Masahiro ; Hasegawa, Masaya ; Hasegawa, Takaaki ; Nabeshima, Toshitaka. / The necessity of adjusting the dosage of zonisamide when coadministered with other anti-epileptic drugs. In: Biological and Pharmaceutical Bulletin. 1996 ; Vol. 19, No. 8. pp. 1090-1092.
@article{237ab9dc1b854adbb0ece325cbd2cb19,
title = "The necessity of adjusting the dosage of zonisamide when coadministered with other anti-epileptic drugs",
abstract = "Zonisamide (ZNS), a new anti-epileptic drug that exhibits a wide anti- epileptic spectrum, is commonly prescribed concomitantly with other anti- epileptic drugs. The interaction between ZNS and other anti-epileptic drugs was investigated in epileptic patients. The steady state plasma levels of all the anti-epileptic drugs were measured by high-performance liquid chromatography. The concomitant administration of phenobarbital (PB), phenytoin (PHT), or carbamazepine (CBZ) with ZNS significantly decreased the ratio of the steady state plasma concentration to the administered dose (C/D ratio) of ZNS, whereas clonazepam (CZP) and valproic acid (VPA) when administered concomitantly with ZNS did not change the C/D ratio. Significant negative correlations were observed between the C/D ratio of ZNS and the doses of PB, PHT, CBZ, and VPA. On the other hand, the ratio of the plasma concentration of carbamazepine-10,11-epoxide (CBZ-E), the major active metabolite of CBZ, to the plasma concentration of CBZ was significantly decreased by concomitant administration with ZNS, indicating that ZNS inhibits the metabolism of CBZ. These findings show that when ZNS is administered concomitantly with these anti-epileptic drugs, it is necessary to monitor the plasma concentration of ZNS in order to adjust its dosage.",
author = "Masahiko Shinoda and Masahiro Akita and Masaya Hasegawa and Takaaki Hasegawa and Toshitaka Nabeshima",
year = "1996",
month = "1",
day = "1",
doi = "10.1248/bpb.19.1090",
language = "English",
volume = "19",
pages = "1090--1092",
journal = "Biological and Pharmaceutical Bulletin",
issn = "0918-6158",
publisher = "Pharmaceutical Society of Japan",
number = "8",

}

The necessity of adjusting the dosage of zonisamide when coadministered with other anti-epileptic drugs. / Shinoda, Masahiko; Akita, Masahiro; Hasegawa, Masaya; Hasegawa, Takaaki; Nabeshima, Toshitaka.

In: Biological and Pharmaceutical Bulletin, Vol. 19, No. 8, 01.01.1996, p. 1090-1092.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The necessity of adjusting the dosage of zonisamide when coadministered with other anti-epileptic drugs

AU - Shinoda, Masahiko

AU - Akita, Masahiro

AU - Hasegawa, Masaya

AU - Hasegawa, Takaaki

AU - Nabeshima, Toshitaka

PY - 1996/1/1

Y1 - 1996/1/1

N2 - Zonisamide (ZNS), a new anti-epileptic drug that exhibits a wide anti- epileptic spectrum, is commonly prescribed concomitantly with other anti- epileptic drugs. The interaction between ZNS and other anti-epileptic drugs was investigated in epileptic patients. The steady state plasma levels of all the anti-epileptic drugs were measured by high-performance liquid chromatography. The concomitant administration of phenobarbital (PB), phenytoin (PHT), or carbamazepine (CBZ) with ZNS significantly decreased the ratio of the steady state plasma concentration to the administered dose (C/D ratio) of ZNS, whereas clonazepam (CZP) and valproic acid (VPA) when administered concomitantly with ZNS did not change the C/D ratio. Significant negative correlations were observed between the C/D ratio of ZNS and the doses of PB, PHT, CBZ, and VPA. On the other hand, the ratio of the plasma concentration of carbamazepine-10,11-epoxide (CBZ-E), the major active metabolite of CBZ, to the plasma concentration of CBZ was significantly decreased by concomitant administration with ZNS, indicating that ZNS inhibits the metabolism of CBZ. These findings show that when ZNS is administered concomitantly with these anti-epileptic drugs, it is necessary to monitor the plasma concentration of ZNS in order to adjust its dosage.

AB - Zonisamide (ZNS), a new anti-epileptic drug that exhibits a wide anti- epileptic spectrum, is commonly prescribed concomitantly with other anti- epileptic drugs. The interaction between ZNS and other anti-epileptic drugs was investigated in epileptic patients. The steady state plasma levels of all the anti-epileptic drugs were measured by high-performance liquid chromatography. The concomitant administration of phenobarbital (PB), phenytoin (PHT), or carbamazepine (CBZ) with ZNS significantly decreased the ratio of the steady state plasma concentration to the administered dose (C/D ratio) of ZNS, whereas clonazepam (CZP) and valproic acid (VPA) when administered concomitantly with ZNS did not change the C/D ratio. Significant negative correlations were observed between the C/D ratio of ZNS and the doses of PB, PHT, CBZ, and VPA. On the other hand, the ratio of the plasma concentration of carbamazepine-10,11-epoxide (CBZ-E), the major active metabolite of CBZ, to the plasma concentration of CBZ was significantly decreased by concomitant administration with ZNS, indicating that ZNS inhibits the metabolism of CBZ. These findings show that when ZNS is administered concomitantly with these anti-epileptic drugs, it is necessary to monitor the plasma concentration of ZNS in order to adjust its dosage.

UR - http://www.scopus.com/inward/record.url?scp=0029779675&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029779675&partnerID=8YFLogxK

U2 - 10.1248/bpb.19.1090

DO - 10.1248/bpb.19.1090

M3 - Article

C2 - 8874824

AN - SCOPUS:0029779675

VL - 19

SP - 1090

EP - 1092

JO - Biological and Pharmaceutical Bulletin

JF - Biological and Pharmaceutical Bulletin

SN - 0918-6158

IS - 8

ER -