Tylenol contains acetaminophen, the active ingredient that provides relief from pain and fever. This drug is commonly bought over the counter, although many consumers have no idea of the health risks: Taking excessive or daily doses of Tylenol can affect your liver enzymes and liver function. Because Tylenol is available without a prescription, some people falsely perceive the drug to be safe, regardless of how it is used.
Liver Enzymes
Your liver is responsible for the normal processing and breakdown of Tylenol. When patients take too much Tylenol for the liver to handle in the normal ways, the excess must be processed by the P450 enzyme system in the liver. This "backup system" creates a toxic byproduct, which tends to deplete the liver's stores of glutathione, which is an antioxidant that protects the liver cells, according to Jobson Medical Information. This depletion can lead to liver cell death and elevation of liver enzymes.
Overdose
More than 100 over-the-counter medications contain the active ingredient in Tylenol, acetominophen, and in the United States and Britain acetominophen overdose is more common than any other kind, according to Life Extension Magazine. Prescription medications also contain acetaminophen and can add to the overuse of this active ingredient in Tylenol.
Many people overdose, not on purpose, but because they are unaware how much acetaminophen they are being exposed to, which increases the risk of overuse. According to Life Extension Magazine, acetaminophen can be toxic in single doses of 7,000 mg or 150 mg per kg of body weight. People can do this unwittingly, for instance by combining heavy doses of Tylenol with the over-the-counter cold remedy Nyquil, which also contains acetominophen. Taking too much Tylenol, or combining Tylenol with drugs that contain acetaminophen, can overwhelm your liver and raise liver enzymes to dangerous levels.
Toxicity
The recommended maximum daily adult dose for Tylenol is 4,000 mg, for no longer than 10 days. Children shouldn't take Tylenol for more than 5 days at the maximum dose of 91 mg per kg of body weight. Infant Tylenol medications are more concentrated than tablets for older children, and parents should take extra care to give infants Tylenol only according to a doctor's instructions, and to measure doses carefully. For patients of any age, if liver enzymes become elevated and toxicity does occur, symptoms can include nausea, vomiting, stomach pain and a general feeling of body discomfort, according to the Mayo Clinic.
At Risk Populations
Even when they've taken only a recommended dose of Tylenol, certain people are more at risk for experiencing elevated liver enzymes: Those who drink alcohol daily, smoke cigarettes or are over age 65 years are at greater risk. Women are at great risk than men. Likewise, patients with diabetes, blood pressure problems, heart disease or liver disease are also at greater risk.
Elevated enzymes associated with Tylenol usage may be temporary and can decrease once the drug has been discontinued, but Tylenol toxicity can also be fatal in some cases. If you suspect you are at risk for any reason, mention your condition to your doctor or pharmacist.
