Cimetidine and Sympazan

In the database of official manuals used in the service creation an interaction registered by statistical results of studies was found, which can either lead to negative consequences for the patient health or strengthen a mutual positive effect. A doctor should be consulted to address the issue of joint drug administration.

Cimetidine may increase the blood levels and effects of cloBAZam. This may increase the risk and/or severity of side effects such as drowsiness, tiredness, drooling, constipation, and breathing difficulties. Separating the dosing times of the two medications by as much as possible may help to minimize the interaction. Otherwise, you may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. Avoid driving or operating hazardous machinery until you know how the medications affect you, and use caution when getting up from a sitting or lying position. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

ADJUST DOSING INTERVAL: Coadministration with cimetidine may increase the plasma concentrations of clobazam as well as its active metabolite, N-desmethylclobazam. When a single 30 mg oral dose of clobazam was administered to six healthy nonsmoking volunteers during treatment with cimetidine (400 twice a day for two weeks), clobazam systemic exposure (AUC) increased by an average of 65% and half-life increased by 38% compared to clobazam administered alone, although the latter did not reach statistical significance. The AUC and half-life of N-desmethylclobazam also increased by an average of 84% and 100%, respectively. However, the rate of formation of N-desmethylclobazam was reduced, which suggests that cimetidine inhibited the elimination of not only clobazam, but also that of the metabolite and to an even greater extent. In another study consisting of nine healthy male volunteers, administration of a single 30 mg oral dose of clobazam eight hours after pretreatment with cimetidine 1000 mg/day for one week increased the AUC and half-life of clobazam by just 17% and 11%, respectively, compared to administration of clobazam alone. The pharmacokinetics of N-desmethylclobazam were not significantly affected in this study.

MANAGEMENT: Caution is advised if clobazam is prescribed in combination with cimetidine. Available data seem to suggest that the magnitude of interaction may be minimized by separating the times of administration of cimetidine and clobazam by as much as possible.

Cimetidine

Generic Name: cimetidine

Brand name: Tagamet HB, Tagamet

Synonyms: n.a.

What is Cimetidine?

Sympazan

Generic Name: clobazam

Brand name: Onfi, Sympazan

Synonyms: n.a.

What is Sympazan?