Methods of treating at least one condition chosen from pain, inflammation, and fever in a critically ill patient in need thereof, comprising administering to the critically ill patient an intravenous pharmaceutical composition comprising ibuprofen using a first dosage regimen, wherein the first dosage regimen produces a first pharmacokinetic profile in critically ill patients that is about equivalent to a second pharmacokinetic profile produced by administration of the intravenous pharmaceutical composition using a second dosage regimen of ibuprofen to non-critically ill patients, wherein the at least one condition of the critically ill patient is thereby treated.