Cimetidine-induced alterations in desipramine plasma concentrations.

Concurrent administration of cimetidine for 4 days to eight patients taking maintenance doses of desipramine led to significant elevations of desipramine (P less than 0.001) and its hydroxylated metabolite 2-hydroxydesipramine (P less than 0.001). The mean increase in desipramine plasma levels was 51% and that for 2-hydroxydesipramine was 46%. The present results suggest that tricyclic antidepressant plasma level monitoring might be indicated for certain patients taking concurrent cimetidine and desipramine.