Earlier this month the Food and Drug Administration (FDA) reported that the Teva Pharmaceuticals generic brand of Wellbutrin XL 300 mg failed to demonstrate therapeutic equivalence and is being removed from the market. This is the result of a process that began in 2007, shortly after the generic version of Wellbutrin XL 300 mg was approved. Teva’s generic brand of Wellbutrin XL is called Budeprion XL (bupropion hydrochloride extended-release tablets), and is one of five generic versions of Wellbutrin XL 300 mg approved by the FDA.
Following the approval, the FDA began to receive multiple reports that patients switched from Wellbutrin XL 300 mg to its generic counterparts were experiencing reduced effectiveness, and the FDA found the complaints to be linked specifically to the Teva product. The FDA asked Teva to conduct a study to compare its 300 mg product bioequivalence to Wellbutrin XL 300 mg. Teva began the study, but terminated it in late 2011 because it was unable to recruit enough patients to obtain the necessary data.
In 2010, the FDA decided to sponsor its own bioequivalence study comparing the two products. It was conducted in 24 adults and was designed to measure both the rate and the extent of release of bupropion in the blood. The results of this study became available in August 2012, and showed that Budeprion XL 300 mg tablets fail to release bupropion in the blood at either the same rate or same extent as Wellbutrin XL 300 mg. The generic version releases the drug at a much faster rate and at a concentration of only 75% of Wellbutrin XL.
Bioequivalence studies have not yet been performed on the other four generics, made by Anchen, Actavis, Watson, and Mylan Pharmaceuticals. The FDA has requested these companies complete their studies and submit their data no later than March 2013. In the meantime, it is strongly recommended you discuss with your health care provider whether you should use one of the other generic formulations or take the brand name Wellbutrin XL. You may also want to talk with either your pharmacy or your health insurance company about the difference in price between the brand name (made by GlaxoSmithKline) and other generic versions of the drug. In the meantime, there is no concern at this time about bioequivalence with the Teva 150 mg version of Budeprion.