A comparative study of the effects of intranasal triamcinolone acetonide aerosol (ITAA) and prednisone on adrenocortical function.

A comparison of adrenocortical function before and after treatment with either intranasal triamcinolone acetonide aerosol (ITAA), prednisone, or placebo was done. Sixty-two male subjects with allergic rhinitis were treated for 6 weeks with either ITAA (220 or 440 micrograms/day), oral prednisone (10 mg/day), or placebo in double-blind, parallel-group fashion. Adrenocortical function was assessed by 6-hour cosyntropin stimulation before and at the end of the treatment period. The placebo-treated and two ITAA-treated groups produced no changes in adrenocortical function with treatment, and the ITAA-treated groups were not different from the placebo-treated group with mean +/- SEM changes in stimulated plasma cortisol (micrograms per deciliter) as follows: placebo, -2.68 +/- 1.77; ITAA 220 micrograms, -2.69 +/- 1.18; ITAA 440 micrograms, -2.96 +/- 1.81. The prednisone-treated group had a mean reduction in adrenocortical function (mean +/- SEM change in stimulated plasma cortisol of -19.8 +/- 1.77 micrograms/dl) that was significant (p less than 0.0001) compared with that of the placebo-treated group. The results of this study indicate that 6 weeks of treatment with 220 micrograms/day or 440 micrograms/day of ITAA has no effect on adrenocortical function, but prednisone, at a dosage of 10 mg/day for 6 weeks, produces partial adrenocortical suppression.