A quick guide to 3 over-the-counter pain pills

Most of us have stood in front of rows of pills at a drugstore wondering what's best for us. Use this information to help you use painkillers safely and effectively.

Relieves fever and mild to moderate pain from headaches, muscle aches, menstruation, colds, sore throat, toothaches, backaches and osteoarthritis. Does not address inflammation.

• How it works: Changes the way the body perceives pain and lowers body temperature.
• Adult dosage: 650 milligrams every four to six hours.
• Side effects: Doses over 3000 milligrams per day can cause stomach bleeding; doses over 4000 milligrams can damage liver. Alcohol exacerbates side effects.
• Drug interactions: Doses of more than 2,275 milligrams per day may increase the blood thinning effect of warfarin.

Relieves the pain and swelling of osteoarthritis, mild to moderate pain from menstruation, headaches, muscle aches, colds, toothaches, backaches, and fever.

• How it works: Stops the production of prostaglandins, which cause pain, fever and inflammation.
• Adult dosage: For arthritis pain, take 300 to 800 milligrams three to four times per day. For other pain (like menstrual cramps or fever), take 200 to 400 milligrams every four to six hours. The maximum dose without a physician's order is 1,200 milligrams daily. Take with food.
• Side effects: May increase the risk of heart attack or stroke, especially in people already at risk. Can cause stomach pain, bleeding, or ulcers.
• Drug interactions: If you take lithium, ibuprofen can increase blood levels of lithium. It can reduce the effect of blood-pressure medications. It is a blood thinner and thus should not be used with warfarin.

Relieves the pain and swelling of osteoarthritis, shoulder pain from bursitis or tendinitis, gout, menstruation, headaches, muscle aches, cold, toothaches and backaches. Also reduces fever.

• How it works: Stops the production of prostaglandins, which cause pain, fever and inflammation.
• Adult dosage: 250 to 500 milligrams twice per day of regular naproxen tablets.
• Side effects: May increase the risk of heart attack or stroke, especially in people already at risk. Can cause stomach pain, bleeding, or ulcers.
• Drug interactions: It can increase the blood levels of lithium and reduce the effect of blood-pressure medications. It is a blood thinner, and thus should not be used with warfarin.

With this handy guide, choosing an effective painkiller has never been easier! Just be sure to contact your doctor if you're currently taking any other medications that may cause unwanted side effects.