I too had chest discomfort, and my cardiologist did tests. They were negative — and expensive.

I decided Mobic was responsible, and we both stopped it. When the Vioxx story broke, I concluded that these problems were a class effect, but I never saw Mobic mentioned.

Our heart symptoms have not returned. I would like to tell the Food and Drug Administration, but I don't have the address. Can you supply it?

Answer: The COX-2 inhibitors Vioxx, Celebrex and Bextra have received a lot of bad publicity during the past several months. A panel of experts for the FDA concluded that all three raise the risk of heart attacks and strokes.

Mobic is also a COX-2 inhibitor. FDA safety officer Dr. David Graham has said preliminary data suggest that Mobic also increases the risk of heart attacks. The company disagrees, maintaining that the data do not show "excessive cardiovascular risk."

Anyone who wishes to report an adverse event to the FDA may e-mail the agency via the Web site www.fda.gov/medwatch or call 1-888-INFO-FDA (1-888-463-6332).

Answer: Generic drugs are supposed to be identical to their brand-name equivalents. They are designed to get into the bloodstream and act just like the original medicine.

For decades we encouraged people to save money by requesting generics whenever possible. But we have heard from so many readers about problems with some generic medicines that we have become concerned.

There have been reports in the medical literature, for example, that the anti-seizure generic phenytoin might not always work as well as the brand name Dilantin. Some endocrinologists worry that generic levothyroxine might not be exactly the same as brand names such as Synthroid or Levoxyl.

Please discuss this issue with your doctor to see if he or she wants to specify a brand-name medicine.