What and Why

What and Why ?

Acetaminophen is most commonly known as the active ingredient found in products manufactured under the name Tylenol. Acetaminophen is an analgesic and anti-pyretic that does not cause stomach irritation. It is not an anti-inflammatory. Acetaminophen can be found in over 200 over-the-counter medications. It is used for temporary relief of mild to moderate pain that results from headaches, muscle aches, arthritis, backaches, toothaches, colds, and fevers. The chemical name for acetaminophen is N- (4-hyroxyphenyl) acetamide.

When and by who ?

In the late 19th century, the drug phenacetin was used for temporarily relieve pain and reduce fever. In 1889, Karl Morner discovered that the body broke phenacetin down into the compound acetaminophen. Acetaminophen was what actually gave relief from pain and reduced fever. When phenacetin was later found to be a dangerous carcinogen, a small company called Mcneil Laboratories decided to manufacture acetaminophen and began selling it after FDA approval in 1955. Because acetaminophen was gentle on the stomach, a strong pain reliever, and an effective fever reducer it was marketed as Tylenol Children’s Elixir. To promote its ability to "put out the fire" it was packaged in a bright red, fire truck shaped box.

How ?

Acetaminophen relieves pain and reduces fever by inhibiting the release of prostaglandins in the central nervous system. Prostaglandins play an important role in the transmission of pain sensations to the brain and the regulation of the body temperature. Acetaminophen is primarily processed in the liver and becomes active in 30-60 minutes.

Who can use it ?

It is safe for adults, children, and pregnant woman when used as recommended. Acetaminophen will pass into breast milk and is safe for a nursing child but should be avoided if possible.

Dosage and cost?

Acetaminophen is most commonly taken orally, but can be given via a suppository. Recommended dosage taken with a full glass of water;

Adult: Oral (pill or liquid) - 500mg every 4 hrs, up to 8 times in 24 hrs., not to exceed 4g/day.

Child: Oral (pill or liquid) - 10-15mg/kg every 4 hours, not to exceed 5 doses/day.

Minimum toxic dose - 6gr

Minimum lethal dose - 15gr

1 generic 500mg pill costs approximately $ .05

1 Tylenol 500mg pill costs approximately $ .16

Side effects ?

Side effects are very rare when taken as recommended. Some people experience minor nausea.

Interactions ?

-Caffeine has been found to enhance the effectiveness of acetaminophen.

-3gr of vitamin C seems to prolong the time acetaminophen stays in the body and could possibly reduce the amount needed for relief of pain or reduction of fever.

-Carbohydrates and foods high in pectin can interfere with the absorption of acetaminophen.

-Milk thistle is known to elevate liver glutathione levels. Glutathione depletion, as a result of improper use of acetaminophen, is known to cause liver damage.

Warnings !

-Avoid alcohol! Use of more than 2 alcoholic drinks/day reduces maximum daily limits to 2 gr/day.

-Use of alcohol in combination with acetaminophen has been associated with liver damage.

-Acetaminophen should not be used for longer than 3 days to treat fever, 10 days to treat pain, or 5 days to treat child’s pain.

-A 500mg dose of acetaminophen equals the pain relieving qualities of 50mg of codeine or 5mg of oxy codone (1 Percocet tablet).

-Be aware of acetaminophen content in other over-the-counter drugs you may be taking in conjunction with eacother. They all add to your total allowable acetaminophen daily intake.

-Acetaminophen overdose is the leading cause of acute liver failure.

Overdose !

An overdose of acetaminophen can occur from a single dose as small as 6gr. Symptoms can include nausea, vomiting, diarrhea, abdominal pain, sweating, seizures, confusion, or irregular heartbeat. Symptoms usually occur 24 hrs. after ingestion. Fortunately there is an antidote, N-acetyl cysteine. Unfortunately it must be administered within 16 hrs. of ingestion. As a result, many people that take an overdose of acetaminophen suffer from liver failure and require a liver transplant or die.

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