Therapeutic Classification: analgesics (centrally acting), opioid analgesics
Pharmacologic Classification: opioid agonists
Absorption: 32% absorbed following oral administration.
Distribution: Widely distributed.
Metabolism/Excretion: Undergoes extensive first-pass hepatic metabolism (97%); metabolites have no analgesic activity; metabolized drug is 99% renally excreted.
Half-Life: 4 hr.
When switching from immediate-release to extended-release product, the same total daily dose can be used.
- PO (Adults ): Immediate release: 50 mg, 75 mg, or 100 mg initially; then every 4–6 hr as needed and tolerated. If adequate analgesia is not achieved within first hr of first dose, additional dose may be given. Doses should not exceed 700 mg on the first day or 600 mg/day thereafter; Extended release: 50 mg twice daily; titrate dose up to 100–250 mg twice daily (not to exceed dose of 500 mg/day).
- PO (Children ≥6 yr and ≥80 kg): Immediate release: 50 mg every 4 hr; may ↑ to 75 mg every 4 hr as needed and tolerated. If adequate analgesia still not achieved, may ↑ to 100 mg every 4 hr to maintain analgesia without intolerable side effects (not to exceed 7.5 mg/kg/day). Duration of treatment should not exceed 3 days.
- PO (Children ≥6 yr and 60–79 kg): Immediate release: 50 mg every 4 hr; may ↑ to 75 mg every 4 hr as needed and tolerated (not to exceed 7.5 mg/kg/day). Duration of treatment should not exceed 3 days.
- PO (Children ≥6 yr and 40–59 kg): Immediate release: 50 mg every 4 hr (not to exceed 7.5 mg/kg/day). Duration of treatment should not exceed 3 days.
Hepatic Impairment
- PO (Adults ): Moderate hepatic impairment: Immediate release: 50 mg every 8 hr initially; then titrate to maintain analgesia without intolerable side effects. Extended release: 50 mg once daily; may titrate up to maximum dose of 100 mg once daily if needed.
