Use of generic drugs has grown dramatically in the US, to the point where currently almost 75% of the drugs we use are generic. This train doesn’t appear about to stop, in fact just the opposite, as generic use continues to rise. From the point of view of saving healthcare resources this is a good thing, though in many cases, a determination made by an insurance company or the government to mandate a shift to a cheaper drug in the class can lead to avoidable side effects.
A great example of this problem occurs in the class of drugs known as statins. In my experience one statin is not identical to another; these drugs are not interchangeable.  I have treated countless patients who develop muscle aches on one statin but not another; some tolerate Lipitor the best, for others it is Crestor, for still others it is Zocor.  Of the three, only Zocor is available generically, though atorvastatin will have a generic version soon after the patent runs out on Lipitor.
Even when atorvastatin becomes available generically it won’t suddenly offer us a one-size-fits-all cost effective choice. As a practicing internist, I need choices; my 45-year-old fireman patient with marked reflux disease shouldn’t be denied relief just because Nexium works for him and Protonix doesn’t, yet only Protonix is covered by his insurance.
Patients are individuals, what works for one doesn’t always work for another, even when you expect it will. Doctors and politicians and pundits must remember this, even as we all seek to reign in out of control healthcare costs.
Marc Siegel MD is a professor of medicine and medical director of Doctor Radio at NYU Langone Medical Center and a Fox News medical correspondent