Acetaminophen, a non-opiod
analgesic without anti-inflammatory effects, was first used in medicine in 1893, but became very widely used
after approval by the FDA in 1950. (It was approved as over-the-counter in 1960.) It is used to treat
both acute and chronic pain. Perhaps the most notable property is that, unlike aspirin, acetaminophen does not
have peripheral anti-inflammatory effects or blood-thinning properties. It is used to relieve mild to
moderate pain or to reduce fevers. It is considered a drug of choice in patients who are aspirin intolerant,
have ulcers, or difficulty in blood clotting. It is available in many dosage forms over the counter and in
strengths for children and adults. Acetaminophen is generally well tolerated. It is used to treat many
conditions such as headache, muscle aches, arthritis, toothaches, backache,
colds and fevers. Acetaminophen may
also be used for purposes other than those listed in this medication guide.
How to Take
Take acetaminophen exactly as directed by your doctor or
follow the instructions on the package. If you do not understand these instructions, ask your pharmacist,
nurse, or doctor to explain them to you. Take each oral dose with a full glass of water.
To ensure that you get a correct dose, measure the liquid forms of
acetaminophen with a special dose-measuring spoon or cup, not with a regular table spoon. If you do not have
a dose-measuring device, ask your pharmacist where you can get one. Shake the liquid well before measuring.
Never take more acetaminophen than is directed. The maximum
amounts for adults are 1 gram (1000 mg) per dose and 4 grams (4000 mg) per day. Taking more acetaminophen could
damage your liver. If you drink more than three alcoholic beverages per day, talk to your doctor before
taking acetaminophen and never take more than 2 grams (2000 mg) per day.
Use acetaminophen for up to 3 days for a fever, up to 10
days for pain, or up to 5 days to treat a child's pain. If the symptoms do not improve, or if they get worse,
stop using acetaminophen and see your doctor. If you are treating a child, talk to your doctor first
if the child is younger than 2 years of age. Read the package carefully and use a pediatric form of the drug
If you drink more than three alcoholic beverages per day or if
you have had alcoholic liver disease, do not take acetaminophen without first talking to your doctor. You
may not be able to take acetaminophen, or you may require a lower dose or special monitoring.
Acetaminophen is in the FDA pregnancy category B. This means that it
is unlikely to harm an unborn baby. Do not take acetaminophen without first talking to your doctor if
you are pregnant.
passes into breast milk. It appears to be safe for use during breast-feeding but should be avoided if possible.
Talk to your doctor before taking acetaminophen if you are breast-feeding a baby.
Be aware of the acetaminophen content of other over-the-counter
and prescription products. Any acetaminophen found in these products counts toward your total daily dose.
Before taking this medication, tell your doctor if you are
taking any of the following drugs:
a barbiturate such as amobarbital (Amytal),
secobarbital (Seconal), pentobarbital (Nembutal), or phenobarbital (Luminal, Solfoton);
rifampin (Rifadin); or
Drugs other than those listed here may also interact with
acetaminophen. Talk to your doctor and pharmacist before taking any prescription or over-the-counter
Acetaminophen may cause false urine glucose test results. Talk to your
doctor if you are diabetic and you notice changes in your glucose levels while you are taking acetaminophen.
Acetaminophen is listed by the American Association of Poison Control
Centers as one of the most common drugs taken in overdose quantities either intentionally or
experience any of the following serious side effects, stop taking acetaminophen and seek emergency medical
an allergic reaction (difficulty breathing; closing of
your throat; swelling of your lips, tongue, or face; or hives);
liver damage (yellowing of the skin or eyes, nausea,
abdominal pain or discomfort, unusual bleeding or bruising, severe fatigue);
blood problems (easy or unusual bleeding or bruising).
These side effects are very rare and are not likely to occur
during proper treatment with acetaminophen. Side effects other than those listed here may occur. Talk to
your doctor about any side effect that seems unusual or that is especially bothersome.
Heavy use of nonaspirin pain releavers does increase the
risk for high blood pressure. In one groundbreaking study, women who took
nonsteroidal anti-inflammatories (NSAIDs), such as ibuprofen, 22 times a
month or more were 86% more likely to have high blood pressure than those
who did not take NSAIDs. Those taking acetaminophen were twice as likely
to be hypertensive. Aspirin did not increase the risk.
of an acetaminophen overdose include nausea, vomiting, diarrhea, abdominal pain, sweating, seizures, confusion,
and an irregular heartbeat. Seek emergency medical attention. There are around 56,000
acetaminophen overdose per year.