VIENNA, AustriaA new oral inhalation system for morphine(Drug information on morphine) is almost as efficient as IV dosing, Aradigm Corp and SmithKline Beecham researchers reported at the 9th World Congress on Pain. B. A. Otulana, MD, said that the dose-corrected bioavailability of morphine with the new device was 75% of that with intravenous morphine, a major increase over the 5% bioavailability achieved with other nebulizers. This approach might provide a useful, noninvasive alternative to parenteral morphine administration.
The Aradigm device uses disposable liquid dosage forms and a hand-held nebulizer to produce fine aerosol particles that can penetrate deep into the lungs. It was tested in comparison to intravenous morphine in 10 healthy adult subjects in an open-label crossover trial.
On separate days, subjects took either 4 mg of morphine IV or four inhalations of aerosolized morphine (a total dose of 8.8 mg). Plasma morphine levels were measured at baseline and for 4 hours after dosing. Both inhaled and intravenous morphine reached peak plasma concentrations in less than 2 minutes after dosing. Dr. Otulana said that relative Cmax (ng/mL) bioavailability of the inhaled dose was 78%, while the area under the curve (AUC) ratio was 163.8% (Table).
This suggests that, at least in healthy volunteers, the morphine inhalation device provides efficient delivery of morphine and a pharmacokinetic profile similar to that of intravenous morphine, Dr. Otulana concluded.