In some instances, drugs prescribed for unrelated medical conditions may be incompatible, either canceling the beneficial effects of one or both, or creating potentially dangerous side effects. Researchers recently found that Tamiflu, an anti-viral drug considered to be a major tool in fighting a flu epidemic, is rendered ineffective by the anti-clotting drug Plavix.

Another known interaction of two commonly prescribed drugs involves cimetidine, used for gastric ulcers and heartburn, and warfarin, which prevents blood clots from forming or growing larger. Researchers have found that cimetidine increases the anti- clotting effects of warfarin, thus creating a danger of excessive bleeding if the two are taken together. There are also potential dangers of using warfarin while taking such popular supplements as Ginko biloba and Ginseng.

In other cases, problems arise when patients combine medications with the same active ingredients, subjecting themselves to overdoses. Though they come in pill, capsule or liquid form, many brand name and generic cold medicines, for instance, contain aspirin and antihistamines. An unknowing consumer, looking for maximum relief, may combine several brands without realizing he or she is simply taking two or three times the recommended dose of these common over-the-counter ingredients.

Similarly, the headache sufferer who receives a Fiorinal prescription needs to be aware that the drug already contains aspirin and should not be taken with more aspirin. Users of the popular prescription anti-cholesterol statin drugs are commonly told by their doctors and pharmacists to avoid grapefruit in any form.

In addition, alerts appear on drug inserts that warn of possible kidney failure when the two are combined. Since grapefruit is not usually listed as a toxic agent, two lessons are evident: first, what you don’t know can hurt you, and second, you can’t take the safety of anything for granted. Here are a few things you can do to protect yourself:

• Tell your doctor and pharmacist about every medication and supplement you take.

• Don’t wait to be told if there might be a dangerous interaction between your medications. You should always ask!

• Use the same pharmacy for all your prescriptions. Its computerized records may flag potential problems.

• Don’t assume that herbal supplements are safe or harmless. These products are unregulated by the FDA, there is no guarantee of either potency or purity.

Finally, the WellPoint mail order pharmacy program keeps track of prescription renewals for ProtectPlus subscribers and will carefully manage subsequent renewals if a patient appears to be over-utilizing a prescription drug. This process helps to ensure that ProtectPlus members use their prescribed drugs in a safe manner.