Frequency not defined. Central nervous system: Transient dizziness
Dermatological: Rash
Based on acetaminophen component: Substrate (minor) of CYP1A2, 2A6, 2C8/9, 2D6, 2E1, 3A4; Inhibits CYP3A4 (weak)
Decreased effect: Barbiturates, carbamazepine, hydantoins, rifampin, sulfinpyrazone may decrease the analgesic effect of acetaminophen; cholestyramine may decrease acetaminophen absorption (separate dosing by at least 1 hour)
Increased toxicity: Barbiturates, carbamazepine, hydantoins, isoniazid, rifampin, sulfinpyrazone may increase the hepatotoxic potential of acetaminophen; chronic ethanol abuse increases risk for acetaminophen toxicity; effect of warfarin may be enhanced
Oral: Adults: Migraine headache: 2 capsules to start, followed by 1 capsule every hour until relief is obtained (maximum: 5 capsules/12 hours)
Tension headache: 1-2 capsules every 4 hours (maximum: 8 capsules/24 hours)
Barker JD Jr, de Carle DJ, and Anuras S, "Chronic Excessive Acetaminophen Use in Liver Damage,"Ann Intern Med, 1977, 87(3):299-301.
Dionne RA, Campbell RA, Cooper SA, et al, "Suppression of Postoperative Pain by Preoperative Administration of Ibuprofen in Comparison to Placebo, Acetaminophen, and Acetaminophen Plus Codeine,"J Clin Pharmacol, 1983, 23(1):37-43.
Licht H, Seeff LB, and Zimmerman HJ, "Apparent Potentiation of Acetaminophen Hepatotoxicity by Alcohol,"Ann Intern Med, 1980, 92(4):511.
Mokhlesi B, Leikin JB, Murray P, et al, "Adult Toxicology in Critical Care: Part II: Specific Poisonings,"Chest, 2003, 123(3):897-922.
