Lung deposition of budesonide from Turbuhaler is twice that from a pressurized metered-dose inhaler P-MDI.
The pulmonary and systemic availability of budesonide after inhalation from a dry powder inhaler, Turbuhaler, and from a pressurized metered-dose inhaler (P-MDI) were compared in healthy volunteers. Two different methods were used to assess pulmonary availability: 1) calculated from the systemic availability corrected for an oral availability of 13% (n = 24); and 2) after blocking of gastrointestinal absorption by administration of a charcoal suspension (n = 13). An intravenous infusion of budesonide was used as a reference. The systemic availability of budesonide, calculated as a geometric mean and expressed as percentage of the metered dose, was 38% for Turbuhaler and 26% for P-MDI. The pulmonary availability, calculated using the first method, was 32% and 15% for Turbuhaler and P-MDI, respectively; and, using the second method, 32% and 18%, respectively. The results of the present study indicate that administration of budesonide via Turbuhaler gives rise to a lung deposition which is approximately twice that of a P-MDI, with less variability, but that systemic availability is only increased by approximately 50%. Thus, the present data suggest that by administrating budesonide via Turbuhaler, instead of a P-MDI, the same degree of asthma control can be achieved with a lower dose, which, in turn, reduces the risk of undesired systemic effects.
Thorsson
L
L
Astra Draco AB, Lund, Sweden.
Edsbäcker
S
S
Conradson
T B
TB
D000284:Administration, Oral; D000328:Adult; D001682:Biological Availability; D001993:Bronchodilator Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D019819:Budesonide; D002606:Charcoal; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007408:Intestinal Absorption; D008168:Lung / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009330:Nebulizers and Vaporizers; D011282:Pregnenediones / Q000008:administration & dosage* / Q000493:pharmacokinetics
D001993:Bronchodilator Agents; D011282:Pregnenediones; D002606:Charcoal; D019819:Budesonide