Discontinuation of Therapy With Bupropion SR

Sir: In the April 1999 issue of the Companion, Drs. Berigan and Harazin¹ report a case of possible bupropion-associated withdrawal symptoms in a patient treated for smoking cessation. The authors describe the emergence of a number of symptoms following abrupt discontinuation of bupropion sustained-release (SR). The occurrence of withdrawal symptoms or a discontinuation syndrome with bupropion has been extensively evaluated in smoking cessation and depression development programs involving over 10,000 patients. In clinical trials (references ² and ³ and Glaxo Wellcome Inc., data on file), patients were monitored for the emergence of posttreatment adverse events 1 week after abrupt discontinuation of therapy. Withdrawal symptoms were not observed in patients treated with bupropion.

It is estimated that 9.5 million patients have used bupropion since it was first marketed. A review of the adverse events associated with the use of bupropion spontaneously reported to Glaxo Wellcome Inc. revealed few cases of withdrawal symptoms following discontinuation of therapy, and a causal relationship to bupropion could not be established. Glaxo Wellcome Inc. reviews all spontaneous reports of adverse events and closely monitors the reports for any type of signal that may suggest a previously unrecognized trend. As with all reported adverse drug events, Glaxo Wellcome Inc. will continue to monitor for other similar cases. Given our clinical trial experience and postmarketing surveillance data, the evidence does not indicate that bupropion is associated with withdrawal symptoms and does not support a general recommendation to taper the dose of bupropion prior to discontinuation.