Paracetamol overdose occurs when someone takes more than the recommended amount of paracetamol, also known as acetaminophen, which is a common pain reliever and fever reducer. The main cause of overdose is consuming a dose that overwhelms the liver’s ability to safely process the drug. Normally, paracetamol is broken down in the liver, where most of it is converted into harmless substances. However, a small portion is metabolized into a toxic compound called N-acetyl-p-benzoquinone imine (NAPQI). Under normal conditions, the liver neutralizes NAPQI using a substance called glutathione. But when too much paracetamol is taken, glutathione stores are depleted, allowing NAPQI to accumulate and cause damage to liver cells, leading to liver toxicity and potentially acute liver failure.
There are several ways paracetamol overdose can happen:
– **Taking a single very large dose**: This is often seen in intentional overdoses or accidental ingestion of a large quantity at once.
– **Repeated excessive dosing over time**: Sometimes people take more than the recommended dose repeatedly, either by misunderstanding dosing instructions or by taking multiple medications containing paracetamol simultaneously.
– **Combining paracetamol with alcohol or other drugs**: Alcohol consumption can increase the risk of liver damage because it also stresses the liver and can reduce glutathione levels. Some prescription opioids are combined with paracetamol, and misuse of these can lead to overdose.
– **Medication errors**: Confusing different formulations or strengths of paracetamol, or giving children adult doses, can cause accidental overdose.
The symptoms of paracetamol overdose usually do not appear immediately. In the first 24 hours, a person may feel nausea, vomiting, sweating, and general discomfort, but these symptoms can be mild or mistaken for other illnesses. After about 24 to 72 hours, signs of liver injury begin to show, such as pain in the upper right abdomen, elevated liver enzymes in blood tests, and sometimes kidney problems. Between 72 and 96 hours, the liver damage peaks, and severe symptoms like jaundice (yellowing of the skin and eyes), confusion, bleeding problems, low blood sugar, and even coma can develop. Without treatment, this stage can be fatal. If the liver damage is very severe, a liver transplant may be necessary.
Treatment for paracetamol overdose focuses on stopping the absorption of the drug if the person arrives early enough, often using activated charcoal, and replenishing glutathione levels with an antidote called N-acetylcysteine (NAC). NAC helps the liver detoxify NAPQI and can prevent or reduce liver damage if given promptly. The timing of treatment is critical; delays can lead to irreversible liver injury.
Because paracetamol is widely available over the counter and included in many combination medications, overdose is one of the most common poisonings worldwide. People may unintentionally overdose by taking multiple products containing paracetamol or by exceeding the recommended daily dose, especially if they have underlying liver conditions or consume alcohol regularly.
In summary, paracetamol overdose is caused by taking more paracetamol than the liver can safely process, leading to toxic buildup of harmful metabolites that damage liver cells. This can happen through a single large dose, repeated excessive doses, drug interactions, or medication errors. Early symptoms are often mild and nonspecific, but severe liver damage can develop within days, requiring urgent medical treatment to prevent life-threatening complications.
