title: Serum concentration of clonazepam and the therapeutic effect of the drug.
abstract: The effect of other anticonvulsants (phenytoin, phenobarbitone and primidone) on serum clonazepam concentrations has been studied. Serum clonazepam concentrations were measured in 47 epileptic patients in whom a dose of clonazepam (3 mg or 6 mg) was added to existing therapy. 44 patients were receiving other anticonvulsants; 3 were not receiving any other medication. Patients on low doses of other anticonvulsants showed high clonazepam concentrations. Patients on multiple therapy with high doses of other anticonvulsants showed excessive side-effects on clonazepam and low serum clonazepam concentrations. We conclude that other anticonvulsants may reduce serum clonazepam concentrations and therefore that clonazepam is best given alone.
mesh_terms: D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000494:pharmacology*; D001570:Benzodiazepinones / Q000097:blood*; D002998:Clonazepam / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000097:blood* / Q000627:therapeutic use; D004827:Epilepsy / Q000188:drug therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010634:Phenobarbital / Q000494:pharmacology; D010672:Phenytoin / Q000494:pharmacology; D011324:Primidone / Q000494:pharmacology
chemical_list: D000927:Anticonvulsants; D001570:Benzodiazepinones; D011324:Primidone; D002998:Clonazepam; D010672:Phenytoin; D010634:Phenobarbital