PULMONARY ADMINISTRATION OF AEROSOLIZED FENTANYL - PHARMACOKINETIC ANALYSIS OF SYSTEMIC DELIVERY

Aims Pulmonary drug delivery is a promising noninvasive method of syst emic administration. Our aim was to determine whether a novel breath-a ctuated, microprocessor-controlled metered dose oral inhaler (SmartMis t(TM), Aradigm Corporation) could deliver fentanyl in a way suitable f or control of severe pain. Methods Aersolised pulmonary fentanyl base 100-300 mu g was administered to healthy volunteers using SmartMist an d the resultant plasma concentration-time data were compared with thos e from the same doses administered by intravenous injection in the sam e subjects. Results Plasma concentrations from SmartMist(TM) were simi lar to those from i.v. injection. Time-averaged bioavailability based upon nominal doses averaged approximate to 100%, and was > 50% within 5 min of delivery. Fentanyl systemic pharmacokinetics were similar to those previously reported with no trends to dose-dependence from eithe r route. Side-effects (e.g. sedation, lightheadedness) were the same f rom both routes. Conclusions Fentanyl delivery using SmartMist(TM) can provide analgetically relevant plasma drug concentrations. This, comb ined with its ease of noninvasive use and transportability, suggests a strong potential for field and domicilliary use, and for patient cont rolled analgesia without the need for i.v. cannulae.