Larger doses may be required during chronic therapy
PO: Rect: (Adults ≥50 kg): Usual starting dose for moderate to severe pain in opioid-naive patients–30 mg q 3–4 hr initially or once 24-hr opioid requirement is determined, convert to controlled-, extended-, or sustained-release morphine by administering total daily oral morphine dose every 24 hr (as Kadian or Avinza), 50% of the total daily oral morphine dose every 12 hr (as Oramorph SR, Kadian, MS Contin), or 33% of the total daily oral morphine dose every 8 hr (as MS Contin). See equianalgesic chart, equianalgesic dosing guidelines. Avinza dose should not exceed 1600 mg/day because of fumaric acid in formulation.
PO: Rect: (Adults and Children <50 kg): Usual starting dose for moderate to severe pain in opioid-naive patients–0.3 mg/kg q 3–4 hr initially.
PO: (Children >1 mo): Prompt-release tablets and solution–0.2–0.5 mg/kg/dose q 4–6 hr as needed. Controlled-release tablet–0.3–0.6 mg/kg/dose q 12 hr.
IM: IV: SC: (Adults ≥50 kg): Usual starting dose for moderate to severe pain in opioid-naive patients–4–10 mg q 3–4 hr. MI–8–15 mg, for very severe pain additional smaller doses may be given every 3–4 hr.
IM: IV: SC: (Adults and Children <50 kg): Usual starting dose for moderate to severe pain in opioid-naive patients–0.05–0.2 mg/kg q 3–4 hr, maximum: 15 mg/dose.
IM: IV: SC: Neonates 0.05 mg/kg q 4–8 hr, maximum dose: 0.1 mg/kg. Use preservative-free formulation.
IV: SC: (Adults) Continuous infusion–0.8–10 mg/hr; may be preceded by a bolus of 15 mg (infusion rates vary greatly; up to 400 mg/hr have been used).
IV: SC: (Children >1 mo): Continuous infusion, postoperative pain–0.01–0.04 mg/kg/hr. Continuous infusion, sickle cell or cancer pain–0.02–2.6 mg/kg/hr.
IV: Neonates Continuous infusion–0.01–0.03 mg/kg/hr.
Epidural: (Adults) Intermittent injection–5 mg/day (initially); if relief is not obtained at 60 min, 1–2 mg increments may be made; (total dose not to exceed 10 mg/day. Continuous infusion–2–4 mg/24 hr; may ↑ by 1–2 mg/day (up to 30 mg/day); Single-dose extended-release liposomal injection–lower extremity orthopedic surgery: 15 mg, lower abdominal/pelvic surgery: 10–15 mg, cesarean section: 10 mg. Use preservative-free formulation.
Epidural: (Children >1 mo): 0.03–0.05 mg/kg, maximum dose: 0.1 mg/kg or 5 mg/24 hr. Use preservative-free formulation.
IT: (Adults) 0.2–1 mg. Use preservative-free formulation.