Drug%252525252520information%252525252520request

# Acetaminophen (Paracetamol) ## Overview Acetaminophen is a non-opioid analgesic and antipyretic. It lacks significant anti-inflammatory activity. Its precise mechanism is likely related to the inhibition of prostaglandin synthesis in the Central Nervous System. ## Primary Indications - Mild to moderate pain - Fever reduction ## Adult Dosing - **Oral/Rectal:** 325 mg to 1000 mg every 4 to 6 hours. - **Maximum Daily Dose:** 4000 mg (Total from all sources). - *Note:* Many health organizations and clinical settings now recommend a lower maximum of 3000 mg per day to reduce hepatotoxicity risk. ## Pediatric Dosing - **Oral/Rectal (Infants/Children):** 10 mg/kg to 15 mg/kg per dose every 4 to 6 hours. - **Maximum Daily Dose:** 5 doses in 24 hours; do not exceed 75 mg/kg/day. ## Dose Adjustments - **Hepatic Impairment:** Use with extreme caution. Reduce total daily dose (often ≤ 2000 mg/day) or extend dosing intervals in patients with chronic liver disease or alcohol use disorder. - **Renal Impairment:** Generally safe at standard doses, but monitor for accumulation if severe renal insufficiency is present. ## Contraindications - Hypersensitivity to acetaminophen. - Severe active hepatic impairment or severe active liver disease. ## Adverse Effects - Generally well-tolerated. - Rare: Skin reactions (e.g., Stevens-Johnson Syndrome). - **Major:** Hepatotoxicity, usually associated with overdose or chronic high-dose use. ## Key Drug Interactions - **Alcohol:** Increases risk of hepatotoxicity (synergistic). - **Warfarin:** Chronic, high-dose use (≥ 2g/day for several days) may potentiate the effect of warfarin; monitor INR. - **CYP2E1 Inducers (e.g., Isoniazid, Rifampin):** May increase production of the toxic metabolite NAPQI. ## Monitoring - Monitor liver function tests (LFTs) in patients on chronic, high-dose therapy. - Monitor for signs of unintentional overdose (combination products containing acetaminophen). ## Clinical Pearls - **Hidden Sources:** Acetaminophen is a component in many over-the-counter and prescription products (e.g., opioid-APAP combinations). Ensure patients track the *total* daily intake across all medications. - **Antidote:** N-acetylcysteine (NAC) is the antidote for acute overdose. - **Weight-based dosing:** Always confirm pediatric dosing by weight rather than age, using the lower end of the weight band. *** **Educational Disclaimer:** This information is for educational purposes only and does not constitute medical advice. Always verify current prescribing information, institutional protocols, and patient-specific factors with verified pharmaceutical references (e.g., Lexicomp, Micromedex) before prescribing or administering medication.