CBNNews.com - Medicines can do a world of good, but taken together, they can sometimes lead to disaster.

The number of medications older adults are taking is increasing. Along with that increase is a growing fear about drug interactions.

In a large study published in the Journal of the American Medical Association, researchers opened the medicine cabinets of 3,000 Americans between the ages of 57 and 85.

The study exposed everything older adults are taking at the same time, not just prescription drugs, but over the counter medications, vitamins and herbal remedies.

Journal authors discovered evidence of risky pill-taking behavior, like combining Niacin with cholesterol lowering Statin medication which increases the odds of muscle weakness.

Taking ginko biloba supplements with aspirin raises the risk for internal bleeding. More dangerous combinations include mixing blood thinning medications together and creating other mixtures that weaken the effectiveness of the drugs.

Dr. Stacey Lindau, University of Chicago Medical Center, said older men are especially at risk for severe reactions.

"One of the important findings is that specifically for older men ages 75 to 85 one in ten were using combinations of drugs that put them at risk for a severe medication interaction," she said.

Patients should make a note of everything they take, then talk to their doctor or pharmacist.

"A lot of patients in general, but more elderly, are shy about what they're on because they think, 'oh this is herbal. It's not going to hurt me in any way,'" pharmacist Candice Carino explained.

"It's not a real drug is what they're thinking. I don't need to tell my doctor. I don't need to tell my pharmacist. It's not going to hurt me. But in reality it can," she said.

Experts agree that opening the lines of communication between patient and health care providers is the best way to ensure all medications will work properly.

*Originally aired February 18, 2009