What are the components of Tylenol 3 (acetaminophen and codeine)?

Components of Tylenol 3

Tylenol 3 is a combination medication containing acetaminophen (325 mg) and codeine phosphate (30 mg) per tablet. 1, 2

Detailed Components

• Acetaminophen (325 mg): An analgesic and antipyretic medication that lacks anti-inflammatory properties 1

  • Acts centrally to relieve pain and reduce fever
  • Does not have the anti-inflammatory effects of NSAIDs
  • FDA has limited the amount of acetaminophen in combination products to 325 mg per dosage unit to reduce risk of liver toxicity 1

• Codeine Phosphate (30 mg): A weak opioid analgesic 1

  • Schedule III controlled substance 1
  • Acts as a prodrug that is metabolized to morphine through the CYP2D6 enzyme pathway 3
  • Provides additional pain relief when combined with acetaminophen 4

Clinical Considerations

• Efficacy: The combination provides better pain relief than either component alone 5, 4

  • Studies show that acetaminophen plus codeine provides clinically useful levels of pain relief in about 50% of patients with moderate to severe postoperative pain, compared with under 20% with placebo 4
  • The combination extends the duration of analgesia by about one hour compared to treatment with acetaminophen alone 4

• Dosing: Typically prescribed as 1 tablet every 4-6 hours as needed for pain 1

  • Maximum daily dose should consider acetaminophen limits (no more than 3-4g of acetaminophen daily) 1
  • Codeine component limits use in certain populations due to metabolism variability 1

• Safety Considerations:

  • Hepatotoxicity risk from acetaminophen, especially with excessive doses or in patients with liver disease 1
  • Respiratory depression risk from codeine, particularly when combined with other CNS depressants 3
  • Genetic variability in CYP2D6 metabolism affects codeine efficacy and safety (poor metabolizers experience less analgesia, while rapid metabolizers may experience toxicity) 1, 3
  • Should not be used with other acetaminophen-containing products to prevent excess acetaminophen dosing 1, 6

• Contraindications:

  • Should be avoided in patients with liver cirrhosis as codeine metabolites may accumulate, causing side effects such as respiratory depression 1
  • Should not be combined with benzodiazepines due to increased risk of respiratory depression and potentially fatal overdose 3

Common Side Effects

• Constipation (reported in 29-36% of patients) 7
• Dizziness (19-24% of patients) 7
• Nausea and vomiting (16-24% of patients) 7
• Dry mouth (15-18% of patients) 7
• Drowsiness and sedation 3

Tylenol 3 is classified as a Schedule III controlled substance in the United States due to the codeine component, reflecting its potential for dependence and abuse, though lower than Schedule II opioids 1.