Sign up for email updates


Back Pain & Osteoporosis
Coronary Heart Disease
Depression & Anxiety
Digestive Disorders
Heart Attack Prevention
Hypertension & Stroke
Lung Disorders
Nutrition & Weight Control
Prostate Disorders




Brand Names: Aceta, Actamin, Anacin-3, Apacet, Aspirin Free Anacin, Atasol, Banesin, Dapa, Datril Extra-Strength, Feverall, Genapap, Genebs, Liquiprin, Neopap, Oraphen-PD, Panadol, Phenaphen, Redutemp, Snaplets-FR, Suppap, Tapanol, Tylenol, Valorin
Drug Class: Analgesic; antipyretic (fever reducer)
Available in: Capsules, caplets, tablets, powder, liquid, suppositories
Available OTC? Yes
As Generic? Yes

Side Effects

Serious: Allergic reaction causing rash, itching, hives, swelling, or breathing difficulty; yellow-tinged skin and eyes (indicating liver damage). Seek medical assistance immediately.

Common: No common side effects have been reported.

Less Common: Sore throat and fever (not present before treatment and not caused by the condition being treated), extreme fatigue or weakness, unexplained bleeding or bruising, blood in urine, painful, decreased, or frequent urination.

Principal Uses

To treat mild to moderate pain and fever, including simple headaches, muscle aches, and mild forms of arthritis. Acetaminophen is useful for patients who cannot take aspirin, such as those taking anticoagulants or suffering from gastro-intestinal ulcers or bleeding disorders.

How the Drug Works

Acetaminophen appears to interfere with the action of prostaglandins, substances in the body that cause inflammation and make nerves more sensitive to pain impulses. It also relieves fever, probably by acting on the heat-regulating center of the brain.


For adults and teenagers: 325 to 650 mg every 4 to 6 hours, or 1 g, 3 to 4 times a day, as needed. Extended-release caplets: Take 2 every 8 hours. Maximum dosage with short-term therapy should not exceed 4 g a day; with long-term therapy it should not exceed 2.6 g a day unless otherwise prescribed by your doctor. For children 12 years and under: Consult a pediatrician for proper dose. Liquid form may be recommended for young children.

Onset of Effect

Within 15 to 30 minutes.

Duration of Action

3 to 4 hours; 8 hours for extended-release form.

Dietary Advice

Take it with water 30 minutes before or 2 hours after meals. It may be taken with milk to minimize stomach upset. If you are on a salt-restricted diet, be sure to account for the sodium present in the powder form of acetaminophen.


Store in a tightly sealed container away from heat and direct light. Refrigerate liquid forms (to make them more palatable) and rectal suppositories. Do not allow the medication to freeze.

If You Miss a Dose

Take it as soon as you remember. If it is near the time for the next dose, skip the missed dose and resume your regular dosage schedule. Do not double the next dose.

Stopping the Drug

Unless directed otherwise by your doctor, limit use to 5 days for children under 12 and 10 days for adults.

Prolonged Use

Prolonged use may lead to liver problems, kidney problems, or anemia in some patients. Talk to your doctor about the need for periodic physical examinations and laboratory tests.


Over 60: Adverse reactions may be more likely and more severe in older patients; lower doses may be warranted.

Driving and Hazardous Work: No problems are expected.

Alcohol: Avoid alcohol; combining the two can cause serious liver problems. Patients with a history of alcohol abuse should not use acetaminophen except under close supervision by a doctor.

Pregnancy: No problems have been reported. Consult your doctor if you are or plan to become pregnant.

Breast Feeding: No problems have been reported.

Infants and Children: No problems are expected; however, some formulations are sweetened with aspartame, which should not be consumed by children with phenylketonuria.


Symptoms: Nausea, vomiting, appetite loss, abdominal pain, excessive sweating, confusion, drowsiness or exhaustion, stomach tenderness, heartbeat irregularities, yellowing of the skin and eyes.

What to Do: If you suspect an overdose, seek medical aid immediately, even if no symptoms are present. Steps must be taken promptly to avoid potentially fatal liver damage.

Drug Interactions

Consult your doctor for specific advice if you are taking anticoagulants (such as warfarin), aspirin, an NSAID, barbiturates, carbamazepine, hydantoins, rifampin, sulfinpyrazone, isoniazid, nicotine, or zidovudine.

Food Interactions

No known food interactions.

Disease Interactions

Consult your doctor if you have liver or kidney disease, diabetes mellitus, phenylketonuria, or a history of alcohol abuse.


From The Johns Hopkins Consumer Guide to Drugs. You can order this book now on our secure server.



Buy now



The arthritis White Paper from The Johns Hopkins White Papers series is an annual, in-depth report written by Hopkins physicians.

Johns Hopkins Consumer Guide to Drugs
Buy now
Johns Hopkins Consumer Guide to Drugs
Find out everything you need to know about medications for arthritis and other conditions in The Johns Hopkins Consumer Guide to Drugs.


    Contact us 
    © 2005 Medletter Associates, Inc.