LUNG DEPOSITION OF BUDESONIDE FROM TURBUHALER(R) IS TWICE THAT FROM APRESSURIZED METERED-DOSE INHALER P-MDI

The pulmonary and systemic availability of budesonide after inhalation from a dry powder inhaler, Turbuhaler(R), and from a pressurized mete red-dose inhaler (P-MDI) were compared in healthy volunteers. Two diff erent methods were used to assess pulmonary availability: 1) calculate d from the systemic availability corrected for an oral availability of 13% (n=24); and 2) after blocking of gastrointestinal absorption by a dministration of a charcoal suspension (n=13). An intravenous infusion of budesonide was used as a reference. The systemic availability of b udesonide, calculated as a geometric mean and expressed as percentage of the metered dose, was 38% for Turbuhaler(R) and 26% for P-MDI. The pulmonary availability, calculated using the first method, was 32% and 15% and for Turbuhaler(R) and P-MDI, respectively; and, using the sec ond method, 32% and 18%, respectively. The results of the present stud y indicate that administration of budesonide via Turbuhaler(R) gives r ise to a lung deposition which is approximately twice that of a P-MDI, with less variability, but that systemic availability is only increas ed by approximately 50%. Thus, the present data suggest that by admini strating budesonide via Turbuhaler(R), instead of a P-MDI, the same de gree of asthma control can be achieved with a lower dose, which, in tu rn, reduces the risk of undesired systemic effects.