Are over-the-counter (OTCs) drugs safe?

There are negative side effects to OTCs just as there are to prescription drugs. Always read labels carefully. OTCs are usually safe as long as warnings and directions are followed. If not taken properly, OTCs can mask the warning signs of a serious illness, make some prescription medicines less effective, or cause an overdose if they are combined with other medications containing the same active ingredients. Always check with your doctor or pharmacist before taking a new OTC especially if you are taking prescription medications.

Gail Carlson, MPH Ph.D., Continuing Medical Education, School of Medicine, 
University of Missouri-Columbia