Calcium channel blockers are being used increasingly for a variety of cardiovascular problems. Diltiazem hydrochloride, a benzothiazepine derivative, has been reported to have a low incidence of adverse side effects. We report a case of acute psychosis associated with the use of diltiazem in a patient receiving lithium carbonate therapy. Both diltiazem hydrochloride and lithium carbonate have calcium antagonist effects in the central nervous system, and we review their mechanisms of action. A possible synergistic drug interaction between diltiazem and lithium is reported.
(Arch Intern Med. 1991;151:373-374)
Binder EF, Cayabyab L, Ritchie DJ, Birge SJ. Diltiazem-Induced Psychosis and a Possible Diltiazem-Lithium Interaction. Arch Intern Med. 1991;151(2):373-374. doi:10.1001/archinte.1991.00400020119023