Intravenous morphine pharmacokinetics in pediatric patients with sickle cell disease

J Pediatr. 1995 Mar;126(3):461-7. doi: 10.1016/s0022-3476(95)70472-8.


To examine the pharmacokinetics of parenteral opioids, such as morphine, in patients with sickle cell disease, we determined the plasma morphine clearances in 18 patients (aged 6 to 19 years) who were receiving continuous intravenous infusions, and the pharmacokinetics of morphine in an additional six patients after single intravenous doses. Plasma morphine clearances ranged from 6.2 to 59.1 ml min-1 kg-1 (35.5 +/- 12.4, mean +/- SD) during steady-state infusions. There was a negative correlation between clearance values and age over the age range studied (p = 0.013). A significant difference (p = 0.042) was also observed in clearance values between patients who had serious adverse symptoms (23.4 +/- 10.7 ml min-1 kg-1) and those who had less serious symptoms (36.3 +/- 6.4 ml min-1 kg-1) when morphine was given at high dosage rates (> or = 0.15 mg kg-1 hr-1). Pharmacokinetic modeling of plasma morphine concentrations adequately fit a two-compartment model with a short initial distribution phase (mean half-life = 4.5 minutes) and a rapid terminal elimination half-life (77.6 +/- 19.2 minutes). These findings suggest that considerable individualization of morphine dosing may be necessary to achieve optimal analgesia and minimal adverse effects in these patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Anemia, Sickle Cell / blood
  • Anemia, Sickle Cell / complications
  • Anemia, Sickle Cell / drug therapy*
  • Child
  • Dose-Response Relationship, Drug
  • Female
  • Humans
  • Infusions, Intravenous
  • Injections, Intravenous
  • Male
  • Morphine / administration & dosage
  • Morphine / pharmacokinetics*
  • Pain / drug therapy*
  • Pain / etiology


  • Morphine