CV: hypotension, bradycardia.
Derm: flushing, itching, sweating.
EENT: blurred vision, diplopia, miosis.
Endo: adrenal insufficiency.
GI: constipation, nausea, vomiting.
GU: urinary retention.
Neuro: confusion, sedation, dizziness, dysphoria, euphoria, floating feeling, hallucinations, headache, unusual dreams.
Resp: RESPIRATORY DEPRESSION (INCLUDING CENTRAL SLEEP APNEA AND SLEEP-RELATED HYPOXEMIA).
Misc: allodynia, opioid-induced hyperalgesia, physical dependence, psychological dependence, tolerance.
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 every 3–4 hr initially or once 24-hr opioid requirement is determined, convert to extended-release morphine by administering total daily oral morphine dose every 24 hr (as ER capsules), 50% of the total daily oral morphine dose every 12 hr (as MS Contin), or 33% of the total daily oral morphine dose every 8 hr (as MS Contin). See equianalgesic chart, Appendix K. Dose of ER capsules 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 every 3–4 hr initially.
- PO (Children >1 mo): Prompt-release tablets and solution: 0.2–0.5 mg/kg every 4–6 hr as needed. Controlled-release tablet: 0.3–0.6 mg/kg every 12 hr.
- IM, IV, SC (Adults 50 kg): Usual starting dose for moderate to severe pain in opioid-naive patients: 4–10 mg every 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 every 3–4 hr, maximum: 15 mg/dose.
- IM, IV, SC (Neonates): 0.05 mg/kg every 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 80 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).
- 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.
AVINza, Duramorph, Embeda, Infumorph, Mitigo, Morphabond ER, MS Contin, Roxanol
Therapeutic Classification: opioid analgesics
Pharmacologic Classification: opioid agonists
Absorption: Variably absorbed (about 30%) following oral administration. More reliably absorbed from rectal, SUBQ, and IM sites. Following epidural administration, systemic absorption and absorption into the intrathecal space via the meninges occurs.
Distribution: Widely distributed to tissues.
Metabolism/Excretion: Mostly metabolized by the liver. Active metabolites excreted renally.
Half-life: Premature neonates: 10–20 hr; Neonates: 7.6 hr; Infants 1–3 mo: 6.2 hr; Children 6 mo–2.5 yr: 2.9 hr; Children 3–6 yr: 1–2 hr; Children 6–19 yr with sickle cell disease: 1.3 hr; Adults: 2–4 hr.
Doloral, Kadian, M-Eslon, Morphine LP Epidural