Background: Current best practice for treating acute severe pain in children is intravenous (IV) or intranasal (IN) opioid. IN diamorphine offers less traumatic analgesia than the potentially difficult and distressing IV route. However, there has been no direct comparison of IN and IV diamorphine nor are there pharmacokinetic data for IN diamorphine in children.
Objective: To compare plasma morphine concentration-time profiles following IN and IV diamorphine.
Setting: City-centre paediatric teaching hospital A&E department.
Patients: Children, aged 3-13 years, with isolated limb fracture.
Interventions: An IV catheter was sited and base-line blood taken. The first 12 children received IV diamorphine (0.1mg/kg), and the subsequent 12, IN diamorphine (0.1mg/kg) in 0.2 ml sterile water drops. Subsequent samples were taken at 2, 5, 10, 20, 30 and 60 minutes.
Measurements: Plasma morphine radioimmunoassay.
Results: Peak plasma morphine concentrations were higher (median 109 vs 36nmol/l), and occurred earlier (median 2 vs 10 minutes), with greater area under the curve (3761 vs 1794nmol/l/h) following IV compared to IN diamorphine (all p<0.0001, Mann-Whitney U test). Higher plasma concentrations at 60 minutes (47 vs 32nmol/l) were also observed following IV diamorphine (p = 0.01, Mann-Whitney U test).
Conclusions: Our evidence supports the wider use of diamorphine by nasal drops in children, showing that adequate plasma levels of morphine are usually achieved. However, we showed significantly attenuated and delayed peak plasma morphine levels with lower levels at one hour compared to IV diamorphine.