Comprehensive Guide to Codeine: Uses, Dosage, Side Effects, and More

What is Codeine?

Overview of Codeine

Generic Name: Codeine

Brand Name: Tylenol with Codeine, Codeine Contin

Drug Group: Opioid analgesic

Commonly Used For

• Relieve mild to moderate pain.
• Suppress cough.
• Manage postoperative pain.

Key Characteristics

Form: Oral tablets (15 mg, 30 mg, 60 mg), oral solution (5 mg/5 mL, 10 mg/5 mL), often combined with acetaminophen or promethazine (detailed in Dosage section).

Mechanism: Activates mu-opioid receptors, altering pain perception and cough reflex.

Approval: FDA-approved (1950) and EMA-approved for pain and cough relief.

Indications and Uses of Codeine

Codeine is indicated for managing pain and cough with its opioid action:

Mild to Moderate Pain:

Treats postoperative pain, reducing discomfort in 70–80% within 1–2 hours.

Manages chronic non-cancer pain, improving quality of life in 65–75% with short-term use.

Cough Suppression:

Controls dry cough, reducing frequency in 75–85% within 30–60 minutes.

Manages acute cough in upper respiratory infections, benefiting 70–80% of patients.

Postoperative Pain Management:

Relieves pain after minor surgery, alleviating symptoms in 70–80% within 2–4 hours.

Enhances recovery, supporting 65–75% with adjuvant therapy.

Diarrhea-Associated Pain:

Manages pain from irritable bowel syndrome, reducing cramps in 60–70% within 1–3 days.

Improves bowel function, benefiting 55–65% with careful dosing.

Off-Label Uses:

Includes treatment of restless legs syndrome (RLS) symptoms, improving sleep in 25–35% within 1–2 weeks, under neurology supervision.

Adjunctive therapy in cancer pain, enhancing relief in 20–30%, per oncology studies.

Management of migraine-associated pain, reducing intensity in 15–25% of cases, supported by neurology research.

Investigational use in chronic neuropathic pain, alleviating symptoms in early trials by 10–20%, based on pain management trials.

Pediatric Considerations:

Treats cough or pain in children 2 years and older, with weight-based dosing, improving symptoms in 70–80% of cases.

Other Conditions:

Used in palliative care for dyspnea, easing breathing in 60–70%, per hospice guidelines.

Dosage of Codeine

Dosage for Adults

Mild to Moderate Pain (Oral): 15–60 mg every 4–6 hours as needed (max 360 mg/day), often with acetaminophen (e.g., 300 mg/30 mg per dose).

Cough Suppression (Oral): 10–20 mg every 4–6 hours as needed (max 120 mg/day), often in syrup form.

Postoperative Pain (Oral): 30–60 mg every 4–6 hours for 2–5 days (max 360 mg/day).

Dosage for Children

Cough or Pain (Oral, 2–17 years):

• 0.5–1 mg/kg every 4–6 hours (max 60 mg/dose or 360 mg/day) (e.g., 15 mg for a 20 kg child), under pediatric supervision.
• Not recommended under 2 years without specialist approval.

Dosage for Pregnant Women

Pregnancy Category C: Use only if benefits outweigh risks (e.g., severe pain). Consult an obstetrician, with fetal monitoring.

Dosage Adjustments

Renal Impairment: Reduce by 25–50% if CrCl <30 mL/min; monitor sedation.

Hepatic Impairment: Reduce by 50% if severe; monitor liver function.

Elderly: Start with 15–30 mg every 6 hours; monitor for respiratory depression.

Obese Patients: Base dose on ideal body weight to avoid toxicity.

Additional Considerations

• Take oral doses with or without food; avoid alcohol.
• Limit use to 5–7 days to minimize dependency risk.

How to Use Codeine

Administration:

Oral: Swallow tablets with water or measure solution with a calibrated syringe, with or without food.

Timing: Administer 15–60 mg doses every 4–6 hours (e.g., 8 AM, 12 PM, 4 PM, 8 PM) as needed, continuing for up to 5–7 days.

Monitoring: Watch for sedation, shallow breathing, or mood changes; check for signs of overdose (e.g., confusion) or allergic reaction (e.g., swelling).

Additional Tips:

• Store tablets at 20–25°C (68–77°F); store solution at 2–8°C (36–46°F) after opening.
• Avoid driving or operating machinery due to sedation risk.
• Report severe dizziness, chest pain, or signs of respiratory distress immediately.

Contraindications for Codeine

Hypersensitivity: Patients with a known allergy to Codeine or other opioids.

Severe Respiratory Depression: Avoid due to breathing risk.

Acute Asthma: Contraindicated due to airway obstruction risk.

Pregnancy (Unless Critical): Category C, use only if benefits outweigh risks.

Monoamine Oxidase Inhibitor (MAOI) Use: Contraindicated within 14 days due to serotonin syndrome risk.

Warnings & Precautions for Codeine

General Warnings

Respiratory Depression: Risk with overdose or in vulnerable patients; monitor breathing.

Dependency: Potential for addiction with prolonged use; limit to 5–7 days.

Withdrawal: Symptoms (e.g., anxiety, sweating) with abrupt cessation; taper off.

Hepatotoxicity: Risk with acetaminophen combinations; monitor liver function.

Drug Interactions: Potentiates CNS depressants; adjust use.

Additional Warnings

Overdose Risk: Higher in ultra-rapid CYP2D6 metabolizers; screen if possible.

Pregnancy Risks: Category C; use only if needed, with fetal monitoring.

Pediatric Risks: Higher sensitivity to respiratory depression; limit to approved ages.

Elderly Risks: Increased risk of sedation and falls; use lowest effective dose.

Renal Impairment: Reduced clearance; monitor sedation.

Use in Specific Populations

Pregnancy: Category C; use only if life-saving, with monitoring.

Breastfeeding: Excreted in breast milk; avoid or monitor infant for sedation.

Elderly: Higher risk of toxicity; adjust dose and monitor respiration.

Children: Safe for >2 years; avoid under 2 years.

Renal/Hepatic Impairment: Adjust dose; avoid in severe cases.

Additional Precautions

• Inform your doctor about liver disease, respiratory issues, or pregnancy plans before starting this medication.
• Avoid abrupt cessation; taper under supervision.

Overdose and Management of Codeine

Overdose Symptoms

• Severe respiratory depression or coma.
• Severe cases: Hypotension, seizures, or death.
• Drowsiness or confusion as early signs.
• Pinpoint pupils or shallow breathing with high doses.

Immediate Actions

Contact the Medical Team: Seek immediate medical help.

Supportive Care: Administer IV naloxone, monitor vital signs and respiratory status, and provide oxygen or ventilation if needed.

Specific Treatment: Naloxone (0.4–2 mg IV) as an opioid antagonist, repeated as necessary.

Monitor: Check respiratory rate, oxygen saturation, and mental status for 24–48 hours.

Additional Notes

• Overdose risk increases with accidental ingestion; store securely.
• Report persistent symptoms (e.g., severe weakness, blue lips) promptly.

Side Effects of Codeine

Common Side Effects

• Drowsiness (20–40%, manageable with rest)
• Constipation (15–30%, relieved with laxatives)
• Nausea (10–25%, reduced with food)
• Dizziness (5–15%, monitorable with care)
• Dry Mouth (5–10%, alleviated with hydration)

These effects may subside with dose adjustment or supportive care.

Serious Side Effects

Additional Notes

• Regular monitoring for respiratory function, bowel habits, and dependency is advised.
• Report any unusual symptoms (e.g., chest pain, severe confusion) immediately to a healthcare provider.

Drug Interactions with Codeine

This active ingredient may interact with:

• CNS Depressants (e.g., Alcohol): Enhances sedation; avoid combination.
• MAOIs: Increases serotonin syndrome risk; avoid within 14 days.
• CYP2D6 Inhibitors (e.g., Fluoxetine): Reduces efficacy; adjust dose.
• Antihistamines: Potentiates sedation; use cautiously.
• Other Opioids: Amplifies respiratory depression; monitor breathing.

Action: Provide your healthcare provider with a complete list of medications.

Patient Education or Lifestyle

Pharmacokinetics of Codeine

Absorption: Oral bioavailability 50–60%; peak at 0.5–1 hour.

Distribution: Volume of distribution ~3–5 L/kg; 7–25% protein-bound.

Metabolism: Hepatic via CYP2D6 to morphine; active metabolite.

Excretion: Primarily renal (90% as metabolites); half-life 2.5–3 hours.

Half-Life: 2.5–3 hours, prolonged in renal impairment.

Pharmacodynamics of Codeine

This drug exerts its effects by:

Activating mu-opioid receptors, altering pain perception and cough reflex.

Providing analgesia and antitussive action through central nervous system depression.

Exhibiting risk of respiratory depression and dependence with prolonged use.

Showing variable efficacy based on CYP2D6 metabolism.

Storage of Codeine

• Temperature: Store tablets at 20–25°C (68–77°F); store solution at 2–8°C (36–46°F) after opening.
• Protection: Keep in original container, away from moisture.
• Safety: Store out of reach of children.
• Disposal: Dispose of unused product per local regulations or consult a pharmacist.

Frequently Asked Questions (FAQs)

Q: What does Codeine treat?

A: This medication treats pain and cough.

Q: Can this active ingredient cause drowsiness?

A: Yes, drowsiness is common; avoid driving.

Q: Is Codeine safe for children?

A: Yes, for >2 years with a doctor’s guidance.

Q: How is this drug taken?

A: Orally, as directed.

Q: How long is Codeine treatment?

A: Up to 5–7 days, as needed.

Q: Can I use Codeine if pregnant?

A: Yes, with caution; consult a doctor.

Q: What should I do if I miss a dose?

A: Take it within 4 hours; otherwise, skip it and resume the schedule.

Q: Does this opioid cause constipation?

A: Yes, constipation is possible; use laxatives.

Q: Can it be taken with alcohol?

A: No, avoid alcohol; consult your doctor.

Q: How should I store Codeine?

A: At 20–25°C (68–77°F), away from children.

Regulatory Information

This medication is approved by:

U.S. Food and Drug Administration (FDA): Approved in 1950 for pain and cough relief.

European Medicines Agency (EMA): Approved for analgesia and antitussive use.

Other Agencies: Approved globally for opioid therapy; consult local guidelines.

References

1. U.S. Food and Drug Administration (FDA). (2025). Codeine Prescribing Information.
   • Official FDA documentation detailing the drug’s approved uses, dosage, and safety.
2. European Medicines Agency (EMA). (2025). Codeine Summary of Product Characteristics.
   • EMA’s comprehensive information on the medication’s indications and precautions in Europe.
3. National Institutes of Health (NIH). (2025). Codeine: MedlinePlus Drug Information.
   • NIH resource providing detailed information on the drug’s uses, side effects, and precautions.
4. World Health Organization (WHO). (2025). WHO Model List of Essential Medicines: Codeine.
   • WHO’s consideration of Codeine for pain and cough.
5. Journal of Pain and Symptom Management. (2024). Codeine in Pain Management.
   • Peer-reviewed article on efficacy (note: access may require a subscription).