In early September, the Food and Drug Administration said it would release its first list of 20 drugs that are being investigated for possible side effects. The agency's new policy of regular quarterly releases of drugs under investigation is the result of 2007 mandatory congressional legislation. There are potential pros as well as cons_

Pros: * Public awareness may grow about drugs that are commonly misused. Oxycontin, a narcotic with a very high potential for overdose and addiction, was listed as being under investigation. * The FDA is being held to a higher standard of disclosure, and this way the public can track its thinking and investigative processes rather than just being shocked by news reports of unpredicted black box warnings. * Physicians may be more cautious to prescribe new treatments without considering potential side effects.

Cons: * Patients may abruptly stop treatments that are working without checking with their physicians. * The lists are cursory - they don't include all drugs under investigation or complete information of the drugs being investigated. Statistics on deaths, hospitalizations, or even numbers of reported side effects are not included. * Knowing that a drug is being reviewed may create fear, and a public perception that is out of proportion to the actual risk. Tysabri is a very effective drug for the treatment of Multiple Sclerosis that is now being investigated for association with skin cancer. Cymbalta is a powerful anti-depressant that is being investigated for urinary complications. Public awareness of these ongoing investigations may severely limit patient willingness to take very effective treatments.

Suspicion of prescription drugs is the prevailing trend, despite the fact that many of these treatments are lifesaving. A case in point is Byetta, a diabetes drug that has been on the market since 2005 with close to a million patients benefitting from its biochemistry. Byetta is an incretin mimetic, which means it is a synthetic hormone which stimulates insuin secretion in response to meals. Not only is this often a smart treatment, and a good arrow to add to the medical quiver, but it also can cause weight loss, which in itself can help to improve glucose control in diabetics.

But news reports of a rare death from pancreatitis (the rate of pancreatitis associated with Byetta is only one in 10,000 cases, and has not been proven as due to the Byetta) has led to public fears of the drug. The drugmaker, Amylin, has seen its stock drop 43 percent in the month since the FDA announced that it was considering a stern warning in response to the potential risk of pancreatitis.

Warnings can be helpful. But fear of essential treatments can also be harmful.

Dr. Marc Siegel is an internist and associate professor of medicine at the NYU School of Medicine. He is a FOX News Medical Contributor and writes a health column for LA Times, where he examines TV and movies for medical accuracy. Dr. Siegel is the author of "False Alarm: the Truth About the Epidemic of Fear" and "Bird Flu: Everything You Need to Know About the Next Pandemic". Read more at www.doctorsiegel.com

Dr. Marc Siegel, a practicing internist, joined FOX News Channel (FNC) as a contributor in 2008..