LET me start by saying I’m a fan of generic drugs. They save Americans billions of dollars each year and give us access to wonderful drugs at affordable prices. I’ve recommended generics in this column many times and use them myself when possible.

But there is a gnawing concern among some doctors and researchers that certain prescription generic drugs may not work as well as their brand-name counterparts. The problem is not pervasive, but it’s something consumers should be aware of  especially now that more insurers insist that patients take generic medications when they are available.

Let me also prepare the groundwork for what I hope will be full and frank reader comments, by acknowledging that this issue is controversial.

Joe Graedon, who has been writing about pharmaceuticals for three decades and runs a consumer advocacy Web site, the People’s Pharmacy (peoplespharmacy.com), was 100 percent behind generics for many years.