codeïne

Codeine is an opioid pain reliever and cough suppressant. It is derived from opium or produced synthetically. As a weaker opioid compared to morphine, it is often prescribed for mild to moderate pain relief. It is also an effective antitussive, meaning it can help suppress cough reflexes, and is therefore found in many prescription cough syrups.

The analgesic effects of codeine are primarily mediated by its conversion in the liver to morphine. This metabolic process varies among individuals due to genetic differences, which can affect how effectively codeine relieves pain and its potential for side effects. Codeine can be administered orally or by injection.

Like other opioids, codeine carries a risk of dependence and addiction. Regular use, even at prescribed doses, can lead to tolerance, where higher doses are needed to achieve the same effect. Withdrawal symptoms can occur if the medication is stopped abruptly after prolonged use. Common side effects include drowsiness, constipation, nausea, and dizziness. Overdose can lead to respiratory depression, a potentially life-threatening condition. Due to these risks, codeine is a controlled substance in many countries and is available only by prescription.