Tylenol #4 Composition
Tylenol #4 contains acetaminophen 300 mg and codeine phosphate 60 mg per tablet 1.
Active Ingredients
Each Tylenol #4 tablet contains two active pharmaceutical ingredients:
- Acetaminophen 300 mg - A non-opioid analgesic and antipyretic (fever reducer) that is not anti-inflammatory 1
- Codeine phosphate 60 mg - A narcotic (opioid) analgesic and antitussive (cough suppressant) 1
Inactive Ingredients
The tablet also contains several inactive ingredients (excipients): colloidal silicon dioxide, corn starch, croscarmellose sodium, crospovidone, magnesium stearate, microcrystalline cellulose, povidone, stearic acid, and FD&C Blue #1 aluminum lake 1.
Related Formulations
The acetaminophen-codeine combination comes in different strengths, all containing 300 mg of acetaminophen but varying amounts of codeine:
- Tylenol #2: 15 mg codeine phosphate
- Tylenol #3: 30 mg codeine phosphate
- Tylenol #4: 60 mg codeine phosphate 1
Important Safety Considerations
The combination of acetaminophen with codeine requires careful attention to total acetaminophen dosing. The FDA has mandated limiting acetaminophen to 325 mg per dosage unit in prescription combination products and recommends a maximum daily intake of 4 grams to reduce the risk of severe liver injury, liver failure, and death 2, 3. When using combination opioid-acetaminophen products, patients must avoid additional acetaminophen from other sources (over-the-counter products) to prevent hepatotoxicity 2, 3.
Codeine requires metabolism via the CYP2D6 enzyme to morphine for its analgesic effect, and genetic variability in this enzyme can result in either inadequate pain relief or excessive opioid effects in different individuals 4, 5.