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BackCodeine Data - Uses, Dosage, Drug class, Brand name, Warnings, etc
| Pharmacology | Codeine is 3-methoxymorphine, a phenanthrene opioid with very low affinity for opioid receptors. Its analgesic activity appears to result from conversion to morphine. Poor metabolizers of debrisoquine/sparteine (~7% of the Caucasian population) cannot convert appreciable amounts of codeine to morphine or obtain analgesia from codeine but are still subject to the same adverse effects. |
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| Administration and Adult Dosage |
- PO, SC, or IM for analgesia: 15–60 mg every 4–6 hr - PO or SC for antitussive action: 10–20 mg every 4–6 hr, to a maximum of 120 mg/day - IV administration not recommended |
| Special Populations - Pediatric Dosage |
- PO, SC, or IM for analgesia (≥1 yr): 0.5 mg/kg every 4–6 hr - PO for antitussive action: • 2–6 yr: 2.5–5 mg every 4–6 hr, to a maximum of 30 mg/day • 7–12 yr: 5–10 mg every 4–6 hr, to a maximum of 60 mg/day • >12 yr: Same as adult dosage |
| Special Populations - Geriatric Dosage | Same as adult dosage. |
| Other Conditions | Reduce initial dosage in debilitated patients or those with hypoxia or hypercapnia. |
| Dosage Forms |
- Tablet: 15, 30, 60 mg - Injection: 15, 30, 60 mg/mL - Oral Liquid: 2, 2.4, 3 mg/mL in various combinations - Formulated as phosphate or sulfate salt |
| Patient Instructions |
- Take as directed; do not exceed recommended dosage - May cause drowsiness; avoid driving or operating machinery until effects are known - Avoid alcohol and other CNS depressants - Report severe constipation, difficulty breathing, or confusion to your physician |
| Missed Doses |
- If taken on a regular schedule, take a missed dose as soon as remembered - If near the time for the next dose, take that dose only; do not double the dose or take extra |
| Pharmacokinetics - Onset and Duration |
- PO, SC onset: 15–30 min - IM peak analgesia: 0.5–1 hr - Duration (all routes): 4–6 hr |
| Pharmacokinetics - Fate |
- Systemic availability: Averages 40% (range 12–84%), reflecting variability in hepatic enzyme activity - Serum Levels (15 mg PO): 26–33 µg/L (82–104 nmol/L) at 2 hr; 13–22 µg/L (41–69 nmol/L) at 5 hr - Protein Binding: 7% - Distribution: Vd = 2.6 ± 0.3 L/kg - Clearance: Cl = 0.66 ± 0.12 L/hr/kg - Metabolism: Hepatic; to codeine-6-glucuronide (major metabolite), norcodeine, and morphine (minor metabolites, ~10% each) via CYP2D6 - Excretion: Primarily urinary as inactive forms; 3–16% unchanged in urine - Morphine accumulation occurs with repeated administration (morphine:codeine AUC ratio 0.29:1) |
| Pharmacokinetics - t¹⁄₂ | - Elimination half-life: 2.9 ± 0.7 hr |
| Adverse Reactions & Side Effects |
Frequent: - Sedation, dizziness, nausea, vomiting, constipation, respiratory depression Dose-related intoxication signs: - Miosis, drowsiness, decreased rate and depth of respiration, bradycardia, hypotension Pediatric (3–5 mg/kg/day): - Somnolence, ataxia, miosis, vomiting Pediatric (>5 mg/kg/day): - Respiratory depression - Infants at particular risk due to incomplete hepatic glucuronidation |
| Contraindications | - Hypersensitivity to codeine or other opioids |
| Precautions & Warnings |
- Do not administer codeine phosphate IV due to risk of severe hypotension - Use with caution in patients with respiratory disease, head injury, increased intracranial pressure, or hepatic impairment - Risk of respiratory depression, especially in infants and poor metabolizers |
| Drug Interactions |
- Potent CYP2D6 inhibitors (e.g., quinidine, fluoxetine) abolish conversion to morphine, reducing analgesic effects - CNS depressants (e.g., alcohol, benzodiazepines) increase risk of sedation and respiratory depression |
| Parameters to Monitor |
- Monitor for respiratory depression, sedation, and constipation - Assess pain relief and adverse effects regularly |
| Class and Drug Brand Name |
- Class: Opioids - Brand Name: Various |
| Notes |
- Codeine is no more effective than placebo in suppressing nighttime cough in children - The American Academy of Pediatrics recommends educating parents about the lack of proven antitussive effects and potential risks of codeine-containing products due to reported overdosage |
References
Hand of Clinical Drug Data