Rethinking the NHS: Promise and Performance

Comments from Lorex Pharmaceuticals The author makes reference to a carbamazepinediltiazem interaction but it should be noted that this is a kinetic interaction, increasing the blood levels of carbamazepine and sometimes giving rise to the known side effects of this drug. There is no evidence of a pharmacodynamic interaction. The cited published report (ref 8) of a possible diltiazem-induced psychosis seems to contain an element of doubt, since as the author makes clear, a re-challenge was unsuccessful (ref 9). Of the two further patients referenced in the case report, the CNS effects in one case were dose-related, in the other the link to the calcium antagonist seems doubtful: one male patient showed irritability and hallucinations on 480 mg/dose of diltiazem. The symptoms disappeared on reducing the dose to 180 mg/day. The other patient, a 70-year-old male alcoholic had hallucinations while taking diltiazem. These continued after the drug was stopped.