Ibuprofen is an effective antipyretic in the postburn period and produces associated decrements in the hypermetabolic response. Burn injury is capable of altering the kinetics of many drugs, making the predictable use of agents such as ibuprofen difficult. Ten patients with serious burns were studied after the administration of 10 mg/kg ibuprofen suspension. The half-life varied from 1.4 to 5.1 hours, depending on the site of administration and/or the presence of solid food. The reported half-life for ibuprofen suspension is 1.8 to 2 hours. Burn size did not alter ibuprofen half-life or area under the time-concentration curve. Maximum ibuprofen concentration varied greatly, depending on route of administration. Time to maximal temperature reduction was between 2 and 3 hours after drug administration. Although the precise level of ibuprofen needed for cyclooxygenase inhibition is unknown, enteral administration results in levels below the targeted 10 to 20 mcg/ml for much of the traditional 6-hour dosing interval. Future studies with ibuprofen in the burn population must standardize more than just total dose.