Generic versions differ in only minor ways

September 23, 2006|By Michael Stroh

Are Wal-Mart's generic drugs just as good as their brand-name equivalents?

Generally speaking, yes. "There is no evidence that any particular brand-name product is superior to a generic formulation," says Dr. Mark Abramowicz, editor of The Medical Letter on Drugs and Therapeutics.

As it does with all prescription medications, the Food and Drug Administration regulates the production and sale of generics. Abramowicz says the FDA ensures that all generic drugs are as safe and effective as their brand-name equivalents. In scientific terms, the two are "bioequivalent."

Aren't there any differences?

Only minor ones. Colors, flavors, and inactive ingredients can differ. Generic pills often have shapes that are different from the originals, too. But the FDA requires that the active chemical ingredient in a generic be present at the same level as in its brand-name counterpart.

I have hypothyroidism and my doctor said he doesn't want me to switch to a generic medication. Why?

The drug you take may be what's known as a "narrow therapeutic index," or NTI, medication.

NTI drugs are so called because they are especially sensitive to dosage, according to James Polli, an associate professor at the University of Maryland School of Pharmacy. Since the amount of active ingredient in a medication can vary slightly from one generic manufacturer to another, some physicians may want to ensure that their patients receive a consistent dose by sticking with the brand-name drug.

"It's important to emphasize that their caution doesn't mean the generic is unsafe," Polli adds.

The good news is that not many drugs are so finicky: Fewer than 5 percent of prescription medications fall into the NTI category. Examples include levothyroxine, for hypothyroidism, and warfarin, a blood thinner.

If generics are the same as brand-name drugs, why are they so cheap?

Because the generic manufacturer didn't have to spend hundreds of millions of dollars to invent and exhaustively test the drug.

The manufacturer of a brand-name drug is generally given patent protection for 20 years. Afterward, other drug companies can introduce their own copies, as long as they've been approved by the FDA.

Generics, by the way, are nothing new. Aspirin was once made exclusively by the German pharmaceutical company Bayer, which patented the drug in 1899. By 1930, generic versions flooded drugstore shelves.

How do I know whether there's a generic equivalent for a drug I'm taking?

Ask your doctor or pharmacist. You can also consult the FDA's Electronic Orange Book, which lists all the equivalents. Visit

Baltimore Sun Articles
Please note the green-lined linked article text has been applied commercially without any involvement from our newsroom editors, reporters or any other editorial staff.