Long-term effect of budesonide on hypothalamic-pituitary-adrenal axis function in children with mild to moderate asthma.

OBJECTIVE To determine the safety of long-term (36 months) administration of an inhaled corticosteroid (budesonide) on hypothalamic-pituitary-adrenal (HPA) axis function in children with mild to moderate asthma. METHODS This was an ancillary study of the Childhood Asthma Management Program (CAMP). Sixty-three children who had mild to moderate asthma and were enrolled in CAMP underwent evaluation of HPA axis function before and 12 and 36 months after receiving continuous therapy with either an inhaled anti-inflammatory agent (budesonide 400 microg/day or nedocromil 16 mg/day) or placebo. HPA axis function was assessed by serum cortisol levels 30 and 60 minutes after 0.25 mg of adrenocorticotrophic hormone (ACTH) and 24-hour urinary free cortisol excretion. RESULTS There were no differences in serum cortisol levels after ACTH stimulation between treatment groups, regardless of time after ACTH administration or months of follow-up. Urinary cortisol excretion per body surface area was similar in both treatment groups at 36 months, after adjusting for age at randomization, race, gender, and clinic. Cumulative inhaled corticosteroid exposure did not influence serum cortisol response to ACTH or urinary free cortisol excretion at 36 months. CONCLUSIONS We found no effects of chronic budesonide treatment at a dose of 400 micro g/day on HPA axis function in children with mild to moderate asthma and demonstrated the absence of a cumulative effect on HPA axis function over a 3-year period.