Usual Adult Dose for Pain. Parenteral: Weight 50 kg or greater: 1000 mg IV every 6 hours OR 650 mg IV every 4 hours. Maximum Single Dose: 1000 mg. Minimum Dosing Interval: every 4 hours. Maximum Dose: 4000 mg per 24 hours. Weight less than 50 kg: 15 mg/kg IV every 6 hours OR 12.5 mg/kg IV every 4 hours. Maximum Single Dose: 15 mg/kg.