Short courses of high-dose inhaled budesonide and serum IgG subclass levels in healthy volunteers

Background: The incidence of systemic side effects of inhaled budesonide increases at doses exceeding 2000 mu g/day. Objective: This study was carried out to investigate whether high-dose inhaled budesonide affects serum IgG subclass concentrations in healthy adult volunteers. Methods: Two groups of 10 subjects each inhaled 2.4 mg of budesonide per day in a double-blind crossover study of morning (8:00 AM and noon, group A) and diurnal (8:00 AM and 8:00 PM, group B) dosing schedules for 4 weeks each, separated by a 2-week washout period. The budesonide was inhaled through a pressurized metered-dose inhaler, mounted on a 750 ml Nebuhaler (ASTRA Pharmaceuticals, Lund Sweden). The IgG subclass levels were determined at baseline and every 2 weeks until the end of the study period (10 weeks). Results: There were no statistically significant changes in the serum IgG subclass concentrations over the 10-week study period in group A, group B, or groups A and B combined. Conclusion: Inhalation of budesonide, 2.4 mg/day, through a large-volume spacer for repented 1-month periods does not influence serum IgG subclass concentrations in healthy adults, suggesting that budesonide does nor cause systemic humoral immunosuppression when given at therapeutic doses.