Brand Name : CODOMOL
Generic Name : Codeine Phosphate 10 mg + Paracetamol 500 mg
Preparation : Tablet
Pharmacological Category : Opioid Analgesic

Mechanism of Action (MOA)
Codeine binds to the opioid receptors μ, κ, δ (mu, kappa, and delta), distributed widely in the central and peripheral nervous system and inhibits the transmission of the pain impulse in the nociceptive afferent neurons. Moreover, codeine shows its analgesic effect profoundly via morphine which binds highly with mu receptor as 10% of codeine is metabolized into morphine. In addition, codeine suppresses cough by direct action in cough centre present in the medulla.

Paracetamol inhibits synthesis of prostaglandin in the central nervous system by inhibiting cyclooxygenase (COX) with a predominant effect on COX-2. Thus, reduction in concentration of prostaglandin lowers the hypothalamic set-point to reduce fever and activates descending inhibitory serotonergic pathways to produce analgesia.

Pharmacokinetics

  • Absorption :
    Codeine : Absorbed from the gastrointestinal tract
    Paracetamol : Rapidly absorbed from the gastrointestinal tract
  • Distribution :
    Codeine : Crossed placenta and in breast milk
    Paracetamol : Most body tissues, crosses the placenta and in breast milk
  • Protein Binding :
    Codeine : 25%
    Paracetamol : Negligible
  • Metabolism :
    Codeine : Liver (metabolites : morphine, norcodeine, normorphine and hydrocodone)
    Paracetamol : Liver (metabolites : glucuronides, sulfate conjugates)
  • Elimination Half-life :
    Codeine : 3 to 4 hours
    Paracetamol : 1 to 3 hours
  • Excretion :
    Codeine : Kidney
    Paracetamol : Kidney

Indications and Dosage
Mild to Moderately Severe Pain, Fever : One to two tablets of CODOMOL every 4 to 6 hours. Maximum : 8 tablets of CODOMOL per day

Side Effects
Acute liver failure, drowsiness, lightheadedness, dizziness, sedation, shortness of breath, nausea, vomiting

Contraindications
Hypersensitivity to paracetamol / codeine, acute respiratory depression, obstructive airways diseases, children undergone tonsillectomy or adenoidectomy, diarrhoea due to poisoning, pseudomembranous colitis, severe active liver disease

Warnings / Precautions

  • Caution in acute alcoholism, convulsive disorders, head injuries and conditions in which intracranial pressure is raised, hypothyroidism, adrenocortical insufficiency, asthma or decreased respiratory reserve, renal or hepatic impairment, prostatic hyperplasia, hypotension, shock, inflammatory or obstructive bowel disorders, myasthenia gravis, elderly or debilitated patients, neonates, labour.
  • Repeated use is associated with the development of psychological and physical dependence.
  • Impairs the mental and physical abilities to perform skilled tasks including driving and operating machinery.

Drug Interactions

  • Increased risk of acute liver failure with alcohol ingestion
  • May enhance effects of other narcotic analgesics, alcohol, general anesthetics, tranquilizers (eg. chlordiazepoxide), sedative-hypnotics, or other CNS depressants.

Pregnancy Category : C

Presentation
CODOMOL : A box of 30 blisters, each blister of 10 tablets