EFFECTS OF INTRANASAL CORTICOSTEROIDS ON ADRENAL, BONE, AND BLOOD MARKERS OF SYSTEMIC ACTIVITY IN ALLERGIC RHINITIS

Background: Intranasal corticosteroids are regarded as the first-line treatment for allergic rhinitis, but few studies have directly compare d their systemic effects. Objective: The purpose of this study was to compare the systemic bioactivity of aqueous formulations of intranasal burdesonide, mometasone furoate (MF), and triamcinolone acetonide (TA A) in terms of adrenal, bone, and white blood cell markers. Methods: T wenty patients with allergic rhinitis, mean age (SE) 35.7 (3.5) years were studied in a single-blind, randomized, 4-way crossover design, wi th treatments separated by 7-day washout periods, comparing placebo wi th budesonide 200 mu g once daily, MF 200 pg once daily, and TAA 220 m u g once daily. After 5 days of treatment at steady-state, serial bloo d and urine samples were taken for 24 hours. Collective and fractionat ed measurements (daytime, overnight, and 8 AM) were done on plasma cor tisol and urine cortisol/creatinine excretion. plasma osteocalcin and blood eosinophil counts were measured at 8 APII. Results: There was no significant difference between placebo and the active treatments with any of the markers of adrenal suppression. Mean values (SE) for 24-ho ur area under the curve plasma cortisol (nmol/L.hr) were placebo, 6312 .9 (564.4); budesonide, 5908.8 (496.8); MF, 6374.1 (509.9); and TAA, 6 239.2 (552.0). Twenty-four hour urinary cortisol/creatinine ratio (nan omoles per millimoles) showed placebo, 9.2 (0.5); budesonide, 8.5 (0.5 ); MF, 8.6 (0.4); and TAA, 8.6 (0.4), The diurnal circadian rhythm was unaffected, and there mere only occasional patients with abnormally l ow cortisol values, There was also no suppression in terms of osteocal cin (placebo, 1.27 nmol/L; budesonide, 1.22 nmol/L; MF, 1.33 nmol/L; a nd TAA, 1.24 nmol/L) and blood eosinophil count (placebo, 0.29 x 10(9) /L; budesonide, 0.27 x 10(9)/L; MF, 0.25 x 10(9)/L; and TAA, 0.24 x 10 (9)/L). Conclusion: Neither budesonide, MF, nor TAA produced significa nt systemic suppression of adrenal, bone, or white blood cell markers at the doses studied. This reflects the good safety profile of these a queous intranasal formulations when taken at clinically recommended do ses.