(HealthDay News) — A dosage of 1 g intravenous acetaminophen every 6 hours yields serum concentrations below 10 µg/mL for critically ill multiple-trauma patients, according to a study published in the Journal of Clinical Pharmacology.
Oscar Fuster-Lluch, PhD, from the Hospital Universitari i Politècnic La Fe in Valencia, Spain, and colleagues examined the pharmacokinetic profile of intravenous acetaminophen administered to critically ill multiple-trauma patients after 4 doses of 1 g every 6 hours. Serum and urine acetaminophen concentrations were assessed and used to calculate pharmacokinetic parameters. Data were included for 22 patients (age, 44 years), mostly males (68%), who were not obese.
The researchers found that the maximum acetaminophen concentration was 33.6 µg/mL and the minimum concentration was 0.5 µg/mL. All values were below 10 µg/mL and 8 were below the limit of detection. Serum and renal clearance were 28.8 L/hour and 15 mL/min, respectively. For a steady-state minimum concentration of 10 µg/mL, the theoretical daily dose would be 12.2 g/day; the dose would be 6.9 g/day for an average steady-state concentration of 10 µg/mL.
“In conclusion, administration of acetaminophen at the recommended dosage of 1 g per 6 hours to critically ill multiple-trauma patients yields serum concentrations below 10 µg/mL due to increased elimination,” the authors write. “To reach the 10 µg/mL target, and from a strictly pharmacokinetic point of view, continuous infusion may be more feasible than bolus dosing.”
- Fuster-Lluch O, Zapater-Hernandez P, Geronimo-Pardo M. Pharmacokinetic study of intravenous acetaminophen administered to critically ill multiple-trauma patients at the usual dosage and a new proposal for administration. J Clin Pharmacol. 2017 Apr 17. doi:10.1002/jcph.903