Oh dear. All those politically-connected prescription management companies (the ones who deny you anything but generic drugs under your health insurance) will have their lobbyists working overtime on this one. Why, you’d almost think the FDA didn’t want to find a problem! (And this is yet another reason why single-payer is the only logical choice to control costs.)

The Food and Drug Administration took a highly unusual step this week: It acknowledged that a widely used generic drug — a copycat of the antidepressant Wellbutrin XL — was not the equivalent of the original drug produced by GlaxoSmithKline since 2003.

The move prompted the world’s largest manufacturer of generic drugs, Israel-based Teva Pharmaceuticals, to stop shipping its generic extended-release bupropion — marketed as Budeprion 300 mg XL– and to remove it from U.S. shelves.

The FDA finding marks an about-face for the food and drug safety agency, which in 2009 responded to public concerns by flatly declaring Teva’s Budeprion XL “bioequivalent and therapeutically equivalent to (interchangeable with) Wellbutrin XL 300 mg.”

The agency’s reversal came after a five-year kerfuffle that has called into question its unqualified assertion that all generic medications work exactly as the more costly “pioneer drugs” they are intended to mimic. With millions of American patients switched — often without notification — to newer, cheaper forms of the drugs they take, this week’s acknowledgment by the FDA may open a small chink on the agency’s so-far impenetrable armor on generic drugs.

“The FDA is not infallible,” write Joe and Terry Graedon, who publish the column “The People’s Pharmacy,” and run an online forum by the same name. “Just because the agency says all generic drugs are identical to their brand-name counterparts does not make it so.”

The Graedons, whose column long ran in The Los Angeles Times, say they have also collected “a great many other complaints” about the generic forms of the beta-blocker Toprol XL (metaprolol) and the anti-seizure drug Keppra (levetiracitam), and have urged the FDA to look into them.