Drug Interaction between Rifampin and Nortriptyline: A Case Report

Abstract

This case illustrates a pharmacokinetic interaction between the tricyclic antidepressant, nortriptyline, and the antituberculosis drug, rifampin. Higher than expected doses of nortriptyline were required to obtain a therapeutic drug level while the patient was receiving rifampin. Following the discontinuation of rifampin, the patient became drowsy and the serum nortriptyline levels rose precipitously into the toxic range. The authors suggest that patients receiving rifampin and nortriptyline, (or other psychotropic drugs) be monitored closely and that similar drug interactions be anticipated.