There is a “rising tide of skepticism” about generic drugs' therapeutic equivalence and CDER efforts to address this has become a top priority, the FDA's director of drug evaluation and research, Janet Woodcock, told a Generic Pharmaceutical Association conference recently.
While generics make up about 65% of prescriptions written and equivalence issues between generics and innovator drugs have been raised in the past, “now we are seeing a lot of pressure about this issue again,” she said. “The generic system works well with bioequivalence determinations and chemistry reviews and so on, but questions do arise, for example ‘are bioequivalence limits tight enough for some specific drug' and I think usually the answer there is ‘yes.'”
During the summer Woodcock's center met with People's Pharmacy columnist and advocate Joe Graedon to discuss reports about therapeutic failures and adverse events when patients were switched from brand name Wellbutrin to Impax's (marketed by Teva) generic equivalent. The FDA agreed to consider doing a bioequivalence study.