If you took a prescription pill recently, odds are it was generic: almost 70 percent of all prescriptions dispensed nationwide were generics in 2007. This totaled $58 billion in sales. Health care insurers see generics as an easy way to cut costs. Pharmacists in most states can freely give patients whichever version of a drug is cheapest, without telling the prescribing doctor; in some states, pharmacies are required to make this switch. And few of us complain when it happens: People who wouldn't dream of substituting Diet Pepsi for Diet Coke, simply because of the taste, eagerly swap vital medications, because the change can cut co-pays in half.

When you fill a prescription, you expect to get the medication your doctor ordered. But pharmacists can legally give different versions of a drug without your knowledge and the consequences can be dire.

This is of special concern to epilepsy patients because doctors and patients spend much time fine-tuning the precise cocktail of medications the keep the seizures at bay. However, a generic may not work exactly like its brand-name counterpart, throwing off the precision in medications. One patient suffered a seizure shortly after her pharmacists unknowingly switched her medication. The consequences could have been graver had she been driving her car instead of her bicycle. As it was, when she fell off the bike, she suffered a broken leg, and a hairline fracture in her left eye socket.

Pharmacists commonly practice "therapeutic substitution," where the pharmacist legally switches a drug prescribed by the physician — but without telling the patient or the physician. Usually, pharmacists replace a brand-name drug with a generic formulation of the exact same medication. Therapeutic substitution is similar but with one crucial distinction: The new drug is in the same class as the old and treats the same condition, but it's not precisely the same medication.

Many lawmakers and health-policy experts say the trend of prescribing generics has little downside. "Generic drugs have the same active ingredient that brand-name drugs do and are made in FDA-approved plants, just as brand-name drugs are," says Aaron S. Kesselheim, M.D., an instructor in medicine at Harvard Medical School in Boston. In an analysis recently published in The Journal of the American Medical Association, Dr. Kesselheim reviewed data from 47 clinical studies and found no evidence that patients on brand-name cardiovascular drugs had clinical outcomes superior to those on generics.

While the dosage may be the same, the drug’s release formula can make a crucial difference. Release formulas, which control how quickly a drug dissolves in your bloodstream, are something drug companies carefully develop and patent. And these release-formula patents often remain in place after the patent on a drug's active ingredient has expired. That means generic companies must sometimes engineer their own release mechanism, as happened in the case of Budeprion XL 300 mg pill. Budeprion XL likely has a different release formula than its brand named counterpart. After patients and physicans made complaints to the FDA, it concluded in a 2008 report that patients' problems were more likely caused by normal relapses of depression than by differences in the drugs. But the report in question and the original approval of Budeprion XL’s 300 mg pill were based solely on data Teva, Budeprion XL’s manufacturer, had submitted for the 150 mg pill; the agency's judgment was that the doses were proportional and would behave similarly in the body. "Neither the FDA nor Teva did the required bioequivalence studies for this pill," counters Tod Cooperman, M.D., president of ConsumerLab.com.

Physicians' groups, including the American Academy of Neurology in St. Paul, Minnesota; the American Heart Association in Dallas; and the Endocrine Society in Chevy Chase, Maryland — all of whose members prescribe drugs that require delicate dosing — have warned doctors to look out for reactions to generics. They've also called on the FDA to study the issue in more detail.

There are ways to keep therapeutic substitution from happening to you. If your physician believes her drug of choice should not be switched for another, ask her to write "medically necessary," "may not substitute," or "DAW" — for "dispense as written" — on the prescription. That obligates the pharmacist to check with you and your physician before making any switches.

For more information please see:

http://www.sciencedaily.com/releases/2001/08/010829083837.htm
http://www.msnbc.msn.com/id/30940044//
http://www.msnbc.msn.com/id/30627962/

Labels: American Academy of Neurology, Generic, Pharmacy, Substitute, Walgreen