Dosage Forms. Tablet: 325 mg, 500 mg; Chewable Tablet: 80 mg, 160 mg; Solution: 500 mg/5 mL, 160 mg/5 mL, 80 mg/0.8 mL; Rectal Suppository: 120 mg, 325 mg, 650 mg
Common FDA Label Indication and Dosing.
1. Pain, headache, fever: Adults, 650-1000 mg po q4h prn (max 4000 mg/24 h); Children aged 3-11 mo, 80 mg po or pr q6h prn; Children aged 1-3 y, 80 mg po or pr q4-6h prn; Children aged 3-6 y, 120 mg po or pr q4-6h prn (max 720 mg/24 h); Children aged 6-12 y, 325 mg po or pr q4-6h prn (max 2.6 g/24 h)
Off-Label Uses. None
MOA. Acetaminophen is a centrally acting analgesic and antipyretic with minimal anti-inflammatory properties. Its analgesic mechanism is unknown, but may be through central inhibition of prostaglandin synthesis.
Drug Characteristics: Acetaminophen
Medication Safety Issues: Acetaminophen
Drug Interactions: Acetaminophen
Adverse Reactions: Acetaminophen
Efficacy Monitoring Parameters. Decreased pain, fever.
Toxicity Monitoring Parameters. Liver function tests, if chronic use; severe skin rash, black tarry stools, yellowing of eyes or skin.
Key Patient Counseling Points. Do not exceed the maximum recommended daily dose; higher doses may result in hepatic injury, including severe hepatotoxicity and death. Avoid alcohol, especially if use is chronic.
Clinical Pearls. Available in a wide range of prescription and OTC products; caution patients to be aware of the total daily dose of acetaminophen taken through various products. Acetaminophen is one of the most commonly implicated medications in accidental or intentional overdoses and requires immediate medical attention. As little as 10 g of acetaminophen ingested as a single dose in adults and children older than 6 y can cause fatal hepatotoxicity. Activated charcoal is given to prevent absorption, and N-acetylcysteine, a sulphydryl donor, is also used to replenish glutathione stores and reduce hepatotoxicity.