Background: Oral controlled-release morphine can provide effective analgesia through a non-invasive route and may facilitate outpatient management of severe episodes of sickle-cell pain. We compared the clinical efficacy and safety of oral morphine with continuous intravenous morphine in children with severe episodes of sickle-cell pain, by a double-blind, randomised, parallel-group design.
Methods: 56 children aged 5-17 years received loading doses of intravenous morphine of up to 0.15 mg/kg, followed by randomly assigned oral morphine 1.9 mg/kg every 12 h plus intravenous placebo (saline), or intravenous morphine 0.04 mg kg-1 h-1, plus placebo tablet. Breakthrough pain was treated with oral, immediate-release morphine 0.4 mg/kg every 2-3 h as required. Pain was assessed daily at 0900 h, 1300 h, 1700 h, and 2100 h with a picture face scale, a pictorial scale (Oucher), a behavioural-observational scale (CHEOPS), and by an investigator.
Findings: 50 children completed the study (28 boys, 22 girls; mean age 11.2 years [SD 3.5]; mean oral morphine dose 2.99 mg/kg daily [0.75]; mean intravenous morphine dose, 0.81 mg/kg daily [0.30]). Mean overall pain scores were similar for oral and intravenous morphine (CHEOPS, 6.3 [1.5] vs 6.4 [1.4], p = 0.8; Oucher, 31.5 [25.4] vs 39.2 [21.7], p = 0.3; Faces, 2.2 [1.4] vs 2.4 [1.3], p = 0.6; clinical rating, 1.7 [0.7] vs 1.9 [0.5], p = 0.3). Opioid analgesia was required for a mean of 4.2 days (1.7) and 5.4 days (2.6), respectively (p = 0.0591). Pain scores from all scales correlated significantly (r = 0.5865-0.8980, p = 0.0001). Frequency of rescue analgesia did not differ significantly between the oral and intravenous morphine groups (0.7 [0.8] vs 0.9 [0.7] doses daily, p = 0.2). Frequency and severity of adverse events did not differ significantly.
Interpretation: Oral, controlled-release morphine is a reliable, non-invasive alternative to continuous intravenous morphine for the management of painful episodes of sickle-cell disease in children.