Acetaminophen is the generic name for the drug commonly known as Tylenol. It is used for the temporary relief of minor aches and pains associated with colds, headaches, backache, toothache, muscular aches, arthritis, menstrual cramps and in the reduction of fever. Acetaminophen usually comes in 500 mg tablets. More than 4 g, or eight tablets of acetaminophen in 24 hours can cause severe liver damage. Additionally, if you drink three or more alcoholic beverages a day, you should not take acetaminophen, as it can damage your liver.
Uses
Acetaminophen is one of the most important drugs used to treat mild to moderate pain when an anti-inflammatory effect is not necessary, according to "Basic and Clinical Pharmacology." Unlike drugs such as aspirin and ibuprofen, acetaminophen does not reduce inflammation. It therefore is not recommended in the treatment of conditions such as arthritis and gout, which are characterized by inflammation. Acetaminophen's ability to relieve pain and reduce fever make it suitable in the treatment of conditions such as the common cold, as well as various aches and pains. It is preferable to aspirin for those who suffer from ulcers, bleeding disorders or asthma.
Absorption
Acetaminophen is taken orally. After passing through the stomach it enters your bloodstream at the level of the small intestine. Peak blood concentrations occur at roughly one hour after you ingest the drug. It travels through your blood to tissues such as your muscles and joints, where it exerts its analgesic, or pain-relieving, effects before making its way to your liver.
Metabolism
Enzymes in your liver metabolize acetaminophen to inactive substances. These compounds, acetaminophen sulfate and glucuronide, then travel to the kidneys, where they are excreted in your urine. However, roughly 5 percent of acetaminophen is excreted in its active form. A small amount of acetaminophen is converted into a highly active metabolite called N-acetyl-p-benzoquinone. In small doses this metabolite does not damage your body. However, if you exceed the recommended daily dosage of 4 g of acetaminophen, this metabolite can build up and damage both your liver and kidneys.
Considerations
Even in therapeutic doses, or under eight tablets per day, some patients experience a mild increase in liver enzymes. In many conditions, such as alcoholism and hepatitis, this laboratory finding can indicate liver damage. However, liver enzymes usually return to normal once you stop taking acetaminophen. With larger doses, dizziness, excitement and disorientation can occur. Jaundice, or a yellow discoloration of the skin, can be a sign of liver damage and usually warrants discontinuation of the drug. If you have additional questions, talk to your doctor.
References
- "Basic and Clinical Pharmacology, 10th edition; Bertram G. Katzung; M.D., Ph.D.; 2009
- "Physiology"; Linda S. Costanzo; 2009
Member Comments