Pharmacy Services

Bupropion Not Always Bioequivalent to Wellbutrin

October 26, 2012

FDA changed the therapeutic equivalence rating of Budeprion XL 300 mg from AB to BX because of results from a more recent bioequivalence study conducted by FDA. The study failed to demonstrate that Budeprion XL 300 mg is therapeutically equivalent to Wellbutrin XL (bupropion 24-hour extended release) 300 mg.  Public concerns regarding bioequivalence data, in general, prompted FDA to perform a direct bioequivalence test in 2010.  Also, FDA received numerous reports of decreased efficacy in patients switching from Wellbutrin XL 300 mg to this particular generic product. Budeprion XL 300 mg tablets are manufactured by Impax Laboratories, Inc. and marketed by Teva Pharmaceuticals USA, Inc.  For the original approval, bioequivalence of Budeprion XL 300 mg tablets was extrapolated from the 150 mg tablet bioequivalence data.

Teva Pharmaceuticals USA, Inc. and Impax Laboratories, Inc. stopped distributing Budeprion XL 300 mg tablets on 9/28/12, and are voluntarily withdrawing the product from the market.  Other marketed generic bupropion XL 300 mg products are manufactured by Actavis, Anchen, Mylan, and Watson. These manufacturers have not conducted formal bioequivalence studies with their products and Wellbutrin XL 300 mg tablets; however, FDA is now encouraging them to conduct these studies. Currently, these products are considered bioequivalent to Wellbutrin XL 300 mg tablets.

Report any adverse events to FDA MedWatch program. Consumers should consult with their pharmacist or healthcare provider or contact FDA Division of Drug Information at (855) 543-3784 or  with any questions.

Additional information is available at the following links:

October 26, 2012; University of Utah, Drug Information Service. Copyright 2012, Drug Information Service, University of Utah, Salt Lake City, UT.