Paracetamol toxicity

Paracetamol toxicity is a condition that results from an overdose of paracetamol, also known as acetaminophen in the United States. This condition is a common cause of acute liver failure, and can potentially be fatal if not promptly and properly treated.

Causes

Paracetamol toxicity typically occurs when a person ingests more than the recommended dose of paracetamol. This can happen either through a single large dose, or through smaller, repeated doses over a period of time. The risk of toxicity is increased in individuals who have certain risk factors, such as chronic alcoholism, malnutrition, or certain genetic factors.

Symptoms

The symptoms of paracetamol toxicity can be divided into four stages. The first stage, which occurs in the first 24 hours after ingestion, may include nonspecific symptoms such as nausea, vomiting, and malaise. The second stage, which occurs 24 to 72 hours after ingestion, is characterized by improvement in gastrointestinal symptoms but worsening of liver function. The third stage, which occurs 72 to 96 hours after ingestion, is characterized by marked liver failure. The fourth stage, which occurs 4 to 14 days after ingestion, is characterized by recovery in survivors.

Diagnosis

Diagnosis of paracetamol toxicity is based on a combination of history, physical examination, and laboratory tests. The most important laboratory test is the measurement of the blood paracetamol level, which can be used to predict the risk of liver damage using the Rumack-Matthew nomogram.

Treatment

The mainstay of treatment for paracetamol toxicity is the administration of N-acetylcysteine (NAC), which acts as an antidote by replenishing the body's stores of glutathione, a molecule that helps to detoxify paracetamol. Other treatments may include supportive care, such as intravenous fluids and treatment of symptoms, and in severe cases, liver transplantation.

Prevention

Prevention of paracetamol toxicity involves education about the dangers of paracetamol overdose, as well as the importance of not exceeding the recommended dose. In addition, individuals who are at increased risk of toxicity, such as those with chronic alcoholism or malnutrition, should be advised to seek medical advice before taking paracetamol.