Kodeinfosfat Alkaloid (Codeine Phosphate Sesquihydrate)

• Codeine phosphate acts on the central nervous system to provide analgesia and cough suppression.
• Mild to moderate pain: provides analgesic relief for conditions such as dental pain, musculoskeletal aches, and postoperative discomfort.
• Cough associated with upper respiratory infections: suppresses the cough reflex to improve patient comfort.
• Acute sore throat pain: reduces pain and irritation in the throat.

• Codeine phosphate is a pro‑drug that is metabolised to morphine, which binds primarily to µ‑opioid receptors in the brain and spinal cord. Activation of these receptors inhibits the release of neurotransmitters involved in pain transmission and diminishes activity of the cough centre in the medulla, resulting in analgesia and cough suppression. It also exhibits weaker activity at κ and δ opioid receptors, contributing modestly to its overall effect.

Codeine phosphate may cause a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Nausea: feeling of sickness or urge to vomit.
• Constipation: reduced bowel movements and hard stools.
• Drowsiness: increased sleepiness or reduced alertness.
• Dry mouth: decreased salivation leading to a sticky sensation.

Serious or Rare Side Effects

• Respiratory depression: slowed or shallow breathing that can be life‑threatening.
• Severe allergic reaction (anaphylaxis): rash, swelling, difficulty breathing.
• Dependence or addiction potential: risk of misuse with prolonged use.

• When prescribing or dispensing codeine phosphate, consider the following safety measures.
• Assess respiratory function: evaluate patients with asthma, COPD, or sleep apnea before initiating therapy.
• Use caution in hepatic impairment: dose may need adjustment in liver disease.
• Avoid in children under 12 years: risk of severe respiratory depression.
• Monitor for signs of dependence: watch for misuse or withdrawal symptoms during prolonged use.
• Concomitant CNS depressants: limit use with alcohol, benzodiazepines, or antihistamines.
• Store at room temperature: keep in the original container, protect from moisture and direct sunlight.

Codeine phosphate can interact with several medicines, altering its efficacy or safety.

Major Interactions (Avoid)

• CNS depressants (e.g., benzodiazepines, alcohol): may cause profound sedation and respiratory depression.
• Monoamine oxidase inhibitors (MAOIs): can precipitate serotonin syndrome.
• Strong CYP2D6 inhibitors (e.g., quinidine, fluoxetine): increase morphine levels and risk of toxicity.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., rifampin, carbamazepine): may reduce analgesic effect.
• Anticholinergic agents (e.g., diphenhydramine): may exacerbate constipation and urinary retention.