Brand-name drugs not better than generics for controlling epilepsy
Research Activities, December 2010, No. 364
The Drug Price Competition and Patent Term Restoration Act of 1984 lets companies bring generic drugs to market by demonstrating that their drug is "bioequivalent" to the brand-name—that is, performs similar to the brand-name drug in pharmacokinetic testing. Since that Act's passage, however, questions have persisted on whether brand-name and generic drugs are indeed interchangeable. A new systematic review and meta-analysis of randomized controlled trials (RCTs) of anti-epileptic drugs finds that brand-name drugs are not superior to generic drugs in treating patients who have epilepsy.
Researchers examined a total of 16 studies, including 9 RCTs, which compared generic and brand-name drugs for treating epilepsy. RCTs involving three brand-name drugs—phenytoin (Dilantin®), carbamazepine (Tegretol®), or valproic acid (Depakene®)—found that these drugs were not superior to generics in controlling seizures. The six observational studies, however, suggested that patients who made the switch to generic drugs for controlling their epilepsy were more likely to change back to the brand-name drug than patients who switched nonepilepsy drugs. While "switchbacks" may indicate that the patient experienced decreased seizure control with the generic drug, the study authors noted that it is also plausible that neurologists may be more likely than other physicians to mistrust generic drugs or that patients requested the change because they were influenced by media or anecdotal reports about the inferiority of generics.
Some observational studies also found that patients who switched to generics tended to use health care services more frequently as a result of the change. The authors suggest that this bump in services might be due to physicians wanting to monitor their patients closely to ensure the generic was meeting the patient's needs. This study was funded in part by the Agency for Healthcare Research and Quality (HS18465).
See "Seizure outcomes following the use of generic versus brand-name antiepileptic drugs: A systematic review and meta-analysis," by Aaron S. Kesselheim, M.D., J.D., M.P.H., Margaret R. Stedman, M.P.H., Ellen J. Bubrick, M.D., and others in the March 26, 2010, Drugs 70(5), pp. 605-621.