Class: Opioid/Acetaminophen Combination Product. C-III
Dosage Forms. Tablet: Acetaminophen/codeine 300 mg/15 mg, acetaminophen/codeine 300 mg/30 mg, acetaminophen/codeine 300 mg/60 mg; Elixir: Acetaminophen/codeine 120 mg/12 mg per 5 mL; Solution: Acetaminophen/codeine 120 mg/12 mg per 5 mL
Common FDA Label Indication, Dosing, and Titration.
1. Pain: Adults, acetaminophen 300-1000 mg (max 4000 mg/d)/codeine 15-60 mg po q4h prn; Children 3-6 y, 5 mL po 3-4 times a day (120 mg acetaminophen/12 mg codeine per 5 mL); Children 7-10 y, 10 mL po 3-4 times a day (120 mg acetaminophen/12 mg codeine per 5 mL)
Off-Label Uses. None
MOA. Acetaminophen is a central inhibitor of prostaglandin synthesis. It has no effects on platelets. Codeine is 3-methoxymorphine, a phenanthrene opioid with very low affinity for opioid receptors. Its analgesic activity appears to result from conversion to morphine.
Drug Characteristics: Acetaminophen/Codeine
Medication Safety Issues: Acetaminophen/Codeine
Drug Interactions: Acetaminophen/Codeine
Adverse Reactions: Acetaminophen/Codeine
Efficacy Monitoring Parameters. Decreased pain.
Toxicity Monitoring Parameters. Liver function tests, SCr, if chronic use; severe skin rash, black tarry stools, excessive drowsiness, yellowing of eyes of skin, change in urination.
Key Patient Counseling Points. If using chronically, use a stool softener and/or laxative for preventing constipation. May cause drowsiness; avoid driving or other tasks requiring motor coordination. Avoid alcohol.
Clinical Pearls. Use caution in elderly, appear more sensitive to the effects. Use of CNS depressants with caution, may have additive effects. Tolerance and physical dependence may occur, avoid abrupt discontinuation. Oral solution contains 7% alcohol. Patients with multiple CYP2D6 gene copies metabolize codeine more rapidly (ultrarapid metabolism), whereas patients who lack functional CYP2D6 genes do not metabolize codeine to morphine and do not experience analgesic effects. Multiple CYP2D6 gene copies occur in 4-5% of Caucasians and is absent in 5-10% of the Caucasian population. Three pediatric deaths post tonsillectomy have been reported in ultrarapid metabolizers. CYP2D6 inhibitors may also prevent activation of codeine to morphine.