Codeine – Dose, ROA, MOA, PK, PD, Indications & More

Dose and Dosage:

  • The typical starting dose of codeine for adults is 15 to 60 mg every 4 to 6 hours as needed for pain relief.
  • The maximum daily dose of codeine should not exceed 360 mg.
  • Dosage may vary based on factors such as the severity of pain, individual response to the medication, and other medical conditions.

Frequency:

  • Codeine is usually administered every 4 to 6 hours as needed for pain relief.
  • It should not be used more frequently or at higher doses than prescribed by a healthcare provider.

Route of Administration (ROA):

  • Codeine is most commonly administered orally as tablets or liquid formulations. It may also be given intramuscularly or intravenously in certain medical settings.

Mechanism of Action (MOA):

  • Codeine is an opioid analgesic that acts as a prodrug. It is metabolized in the liver to its active form, morphine, which exerts its analgesic effects by binding to opioid receptors in the central nervous system.
  • Morphine activates opioid receptors, leading to inhibition of pain transmission and modulation of pain perception.

Pharmacokinetics (PK):

  • Codeine is rapidly absorbed from the gastrointestinal tract after oral administration.
  • It undergoes extensive metabolism in the liver by various cytochrome P450 enzymes, primarily CYP2D6, to form morphine and other metabolites.
  • The onset of action of codeine is usually within 30 to 60 minutes after oral administration.
  • The elimination half-life of codeine is approximately 2.5 to 4 hours, but this may be prolonged in individuals with impaired liver or kidney function.

Pharmacodynamics (PD):

  • Codeine produces analgesia by binding to opioid receptors in the brain and spinal cord, inhibiting pain transmission pathways, and altering the perception of pain.

Pathophysiology:

  • Codeine is indicated for the management of mild to moderate pain and as an antitussive agent for the relief of cough.

Indications:

  1. Pain Relief: Codeine is commonly prescribed for the relief of mild to moderate pain, such as that associated with dental procedures, injuries, or certain medical conditions.
  2. Cough Suppression: Codeine may be used as an antitussive agent to suppress dry, non-productive cough.

Contraindications:

  • Hypersensitivity to codeine or other opioids
  • Severe respiratory depression
  • Acute or severe bronchial asthma
  • Paralytic ileus
  • Use of monoamine oxidase inhibitors (MAOIs) within the past 14 days

Drug Interactions:

  • Codeine may interact with other medications that depress the central nervous system, such as benzodiazepines, alcohol, sedatives, or tranquilizers, leading to additive effects on respiratory depression and sedation.
  • Concomitant use of codeine with drugs that inhibit or induce cytochrome P450 enzymes, particularly CYP2D6, may alter codeine metabolism and efficacy.

Monitoring and Laboratory Tests:

  • Patients receiving codeine therapy should be monitored for signs of respiratory depression, sedation, and opioid-related adverse effects.
  • Regular assessment of pain intensity, response to treatment, and the need for dose adjustments is important to ensure optimal pain management while minimizing the risk of adverse effects.

Why is this medication prescribed?

Codeine is prescribed for the management of mild to moderate pain and as an antitussive (cough suppressant). It belongs to a class of medications known as opioid analgesics.

How should this medicine be used?

  • Follow the instructions provided by your healthcare provider or pharmacist.
  • Take codeine exactly as prescribed, and do not exceed the recommended dosage or frequency of use.
  • Codeine is typically taken orally, either in tablet or liquid form, with or without food.
  • Swallow the tablets whole with a full glass of water. Do not crush, chew, or break the tablets.
  • Measure liquid doses carefully using a special measuring spoon or device. Do not use a household spoon to measure the dose.

Other uses for this medicine

  • Codeine may be prescribed for purposes other than those listed here. It should only be used for the condition for which it was prescribed and under the guidance of a healthcare professional.

What special precautions should I follow?

  • Inform your doctor about any allergies you have, especially to codeine or other opioids.
  • Inform your doctor about your medical history, especially if you have a history of respiratory disorders, liver or kidney disease, substance abuse, mental health disorders, or if you are pregnant or breastfeeding.
  • Avoid consuming alcohol while taking codeine, as it may increase the risk of side effects such as drowsiness or respiratory depression.

What special dietary instructions should I follow?

  • There are no specific dietary restrictions associated with codeine use. However, maintaining a balanced diet and staying hydrated may help support overall health and well-being.

What should I do if I forget a dose?

  • If you miss a dose of codeine, take it as soon as you remember, unless it is almost time for your next dose.
  • Do not double the dose to make up for a missed one. Resume your regular dosing schedule.

What side effects can this medication cause?

Common side effects of codeine may include:

  • Drowsiness
  • Dizziness
  • Constipation
  • Nausea or vomiting
  • Dry mouth

Serious side effects may include:

  • Respiratory depression (slow or shallow breathing)
  • Severe allergic reactions (rash, itching, swelling, difficulty breathing)
  • Changes in mood or mental status (confusion, hallucinations)

What should I know about storage and disposal of this medication?

  • Store codeine tablets and liquid at room temperature away from moisture, heat, and light.
  • Keep the medication out of reach of children and pets.
  • Do not share codeine with others, especially those with a history of substance abuse.
  • Dispose of any unused or expired medication properly, following local regulations or guidelines.

In case of emergency/overdose

  • If you suspect an overdose of codeine or experience symptoms such as extreme drowsiness, difficulty breathing, or loss of consciousness, seek immediate medical attention or call your local poison control center.
  • Be prepared to provide information about the type and amount of medication ingested, as well as any other relevant medical history.