Just because a medication is available without a doctor's prescription doesn't mean that it's risk-free. Over-the-counter (OTC) drugs can be dangerous.

Example: The leading cause of acute liver failure isn't alcohol or hepatitis but an overdose of acetaminophen, the active ingredient in Tylenol.

OTC drugs can be dangerous even when taken in the recommended dosages. Here are common OTC medications and their dangers...


The class of medications called nonsteroidal anti-inflammatory drugs (NSAIDs) relieve pain, tenderness, inflammation and stiffness.

Popular brands: Ibuprofen is in Advil, Excedrin IB, Midol Cramp, Motrin and Nuprin... naproxenisin Aleve... ketoprofen is in OrudisKT.

Dangers: Gastrointestinal irritation as well as bleeding. ..peptic ulcers. . .kidney complications . . .reduced effectiveness of some blood pressure lowering medications...rebound headaches (the pain reliever itself can cause headaches as the medication builds up in the body).

What to do: Before taking an NSAID, consult a doctor if you are older than age 60 and you are taking a prescription anticoagulant, steroid, diuretic or hypertension drug daily.


Aspirin is a type of NSAID that relieves mild to moderate pain.. .reduces fever and swelling... and reduces the risk of heart attack and stroke.

Popular brands: Alka-Seltzer Effervescent Pain Reliever and Antacid, Bayer Aspirin, Excedrin Extra Strength, St. Joseph Adult Chewable Aspirin.

Dangers: Stomach upset. . vomiting...ulcers...inhibited blood clotting. Children younger than age 18 who have chicken pox or flu can develop a rare, life-threatening condition called Reye's syndrome.

What to do: Take aspirin with a full glass of water or milk, or try coated tablets to avoid stomach upset.

Consult your doctor if you are taking blood thinners, corticosteroids, such as hydrocortisone or prednisone, or medications for gout or hypertension-all can react negatively with aspirin.


Relieves pain and fever.

Popular brands: Tylenol, Excedrin Quick Tabs. Many OTC products contain acetaminophen along with other active ingredients. These include Allerest, Sine-Off, St. Joseph Cold Tablets for Children, Sudafed Non-Drowsy Sinus Headache.

Dangers: Liver damage.

What to do: Avoid taking multi symptom OTC medicines that duplicate ingredients.

Important: If you regularly have more than three alcoholic drinks daily, consult your doctor.

Calcium Carbonate

Relieves heartburn, acid indigestion and other stomach upset.

Popular brands: Alka-Mints, Caltrate 600, Rolaids Calcium Rich, Tums.

Dangers: May decrease the effectiveness of certain prescription medicines, including the heart drug digoxin, the anticonvulsant phenytoin and the antibiotic tetracycline.

What to do: Consult your doctor if you are taking any prescription drug. Do not take calcium carbonate within two hours of taking any other medication.


An antihistamine that relieves red, irritated, itchy, watery eyes...sneezing...and runny nose caused by hay fever, allergies and the common cold. It also may relieve the itching that is caused by insect bites, sunburn and poison ily It is used in sleep aids as well because it causes drowsiness.

Popular brands: Benadryl, Excedrin PM, Sominex, Tylenol PM, Unisom.

Dangers: Drowsiness, decreased mental alertness, memory loss.

What to do: Avoid exceeding the maximum dosage (generally 100 milligrams [mg] every four to six hours). This can easily happen if, for example, you're taking an antihistamine and a sleep aid that both contain diphenhydramine. Don't drive a car or operate machinery until you know how this drug affects you.


A decongestant that relieves stuffy nose and clogged sinuses caused by colds, allergies and hay fever.

Popular brands: Sinutab, Sudafed. Some OTC products, such as Advil Cold and Sinus Caplets and Tylenol Sinus Daytime, contain pseudoephedrine along with other active ingredients.

Dangers: Increased blood pressure...rapid heart beat...insomnia.

What to do: Avoid caffeinated beverages because they can increase restlessness and insomnia. Do not use pseudoephedrine if you have taken an MAO inhibitor (a type of antidepressant) within the last two weeks-the combination can cause dangerously high blood pressure.

Consult a doctor if you have hypertension, an overactive thyroid gland or difficulty urinating due to an enlarged prostate gland-pseudoephedrine can aggravate these conditions


An antitussive that relieves a dry (nonproductive) cough caused by a cold or flu.

Popular brands: Benylin Cough Suppressant, Robitussin DM Cough Syrup, Sucrets 8-Hour Cough Suppressant, Vicks 44 Cough Relief.

Dangers: Dizziness, even hallucinations and seizures, if taken in excessive doses (more than 10 times the recommended dosage of 30 mg daily).

What to do: Follow the dosage recommendation on the label. Use the measuring device that comes with the medication, not a house hold tablespoon or teaspoon. If you misplace the device, ask your pharmacist for an appropriate replacement.

Want to Keep Reading?

Continue reading with a Health Confidential membership.

Sign up now Already have an account? Sign in