The FDA finds it acceptable for generics to use different time-release technology than their brand-name counterparts. Although the rate and extent of absorption must be similar enough to be deemed "medically insignificant," lab data and/or test results from a small group (typically 24 to 36 people) of healthy volunteers (typically male) -- provided by the manufacturer -- are considered sufficient to demonstrate this. Clinical testing -- multiphase studies done on thousands of patients to determine safety and effectiveness, which brand-name drugs undergo -- is not required for generics. The assumption is that the innovator drug was already thoroughly tested on humans, so if the generic can be shown to perform "in the same manner" in the lab, then it will perform similarly in patients.
Yet, although generics must have the same active ingredients as the brand-name product, they can include any number of different inactive ingredients (colorings, flavorings, binders, diluents, fillers, etc.) that can cause differences in how well a particular patient absorbs and tolerates a particular medication -- especially patients with allergies, sensitivities or gastrointestinal disease. Formulas also vary from one generic manufacturer to the next. So someone who has success with, say, Company X's Zoloft generic may have trouble if his or her pharmacist refills a prescription with Company Y's version. Which is what happened to me. Once I'd made the rounds of neighborhood pharmacies and found one that carried my old generic brand, my symptoms improved.
For the majority of generic drugs, the abbreviated approval process and FDA-sanctioned differences don't present a significant problem. But the success of those generics doesn't justify the FDA's loud and persistent denial of problems with others -- Ambien, Klonopin, Ritalin, OxyContin, Vicodin, Valium, Toprol, Synthroid and Dilantin, to name a handful.
At the moment, this appears to be a situation that's about to get worse before it gets better. In fiscal year 2007, the FDA approved a record 682 generic drug products, 30% more than in 2006. And in October, it launched the Generic Initiative for Value and Efficiency (with the cute acronym GIVE), which aims to boost approvals further.
The solution, however, isn't to do away with generics, or to make their approval process as rigorous as that of innovator drugs -- that would only drive up costs and defeat the purpose of having generic drugs at all. The FDA should simply 'fess up about the differences that can exist between generics and brand-name drugs and acknowledge the potential repercussions. The agency should take a little initiative and educate physicians and pharmacists about the differences. And then it's up to the white coats -- doctors and pharmacists -- to spend an extra 68 seconds with their patients to explain that there are, in fact, differences between brand-name and generics, and between generics and generics.
Finally, the FDA would do well to be a bit less dismissive of consumer complaints. After all, just because people who rely on antidepressants may have a mental illness doesn't mean we're crazy.