title: Interactions between calcium channel blockers and the anticonvulsants carbamazepine and phenytoin.
abstract: We describe a retrospective analysis of the frequency of adverse interactions between calcium channel blockers and anticonvulsant drugs (phenytoin and carbamazepine) in a series of 43 patients. Ten patients receiving carbamazepine and three patients receiving phenytoin exhibited symptoms or signs of toxicity. Toxicity occurred with both diltiazem and verapamil, but not with nifedipine. These results emphasize the need for careful clinical and laboratory monitoring of patients receiving both classes of medication.
authors.affiliation: Department of Medicine (Neurology), University of Washington, School of Medicine, Seattle.
authors.forename: F H
authors.initials: FH
authors.lastname: Bahls
authors.forename: J
authors.initials: J
authors.lastname: Ozuna
authors.forename: D E
authors.initials: DE
authors.lastname: Ritchie
mesh_terms: D000368:Aged; D000787:Angina Pectoris / Q000150:complications* / Q000188:drug therapy; D002121:Calcium Channel Blockers / Q000009:adverse effects* / Q000627:therapeutic use; D002220:Carbamazepine / Q000009:adverse effects* / Q000627:therapeutic use; D004110:Diltiazem / Q000009:adverse effects; D004347:Drug Interactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000009:adverse effects; D010672:Phenytoin / Q000009:adverse effects* / Q000627:therapeutic use; D012189:Retrospective Studies; D012640:Seizures / Q000150:complications* / Q000188:drug therapy; D014700:Verapamil / Q000009:adverse effects
chemical_list: D002121:Calcium Channel Blockers; D002220:Carbamazepine; D010672:Phenytoin; D014700:Verapamil; D004110:Diltiazem; D009543:Nifedipine