More than 75% of us take an OTC pain reliever at least once a month. What is safe and effective and for what types of pains: Acetaminophen (Tylenol) Reduces fever. Relieves mild to moderate musculoskeletal pain. Relieves mild to moderate back pain. Relieves mild to moderate headaches. Often helpful with colds, sore throat pain, toothaches. Cautions: Alcohol and Tylenol in excess can damage the liver; can interact with the blood thinner Warfarin (Coumadin). Aspirin (Bayer, Excedrin, Ecotrin, St Joseph, Bufferin) Reduces fever. Relieves mild toothaches. Relieves moderately sore muscles. Relieves mild to moderate back pain. Relieves mild to moderate headaches. Cautions: DO NOT TAKE if less than 18 years old;.