Kodeina

Kodeina, commonly known in many languages as codeine, is an opioid analgesic and antitussive derived from the opium poppy. It occurs naturally in small amounts in Papaver somniferum and is also produced synthetically. Chemically, kodeina is a phenanthrene alkaloid with the formula C18H21NO3. In the body, kodeina acts as a prodrug of morphine, undergoing O-demethylation primarily via the cytochrome P450 enzyme CYP2D6 to produce morphine, which mediates most of its analgesic effects.

Medical uses include relief of mild to moderate pain and suppression of non-productive cough. It is commonly formulated in combination products with acetaminophen (paracetamol) or aspirin, and may be prescribed for short-term pain management when alternatives are insufficient.

Pharmacology: As a mu-opioid receptor agonist, kodeina provides analgesia through morphine after metabolism. Onset typically within 30-60 minutes with a duration of several hours. The analgesic effect varies across individuals, because CYP2D6 activity ranges from poor to ultra-rapid metabolizers. Therefore, some people experience little pain relief while others are at risk of morphine toxicity at standard doses.

Safety and side effects: Common opioid-associated effects include drowsiness, dizziness, constipation, nausea, and respiratory depression in overdose. Codeina carries a risk of dependence and withdrawal; it may be unsafe in certain populations, including children and during breastfeeding. Interactions with alcohol, benzodiazepines, and certain antidepressants can increase sedation and respiratory risk.

Regulation: Codes and legal status vary by country. In many jurisdictions kodeina/codeine is a controlled substance or requires a prescription; some places limit use in children or postoperative patients and impose restrictions on packaging and dosing due to misuse potential.