Endocrine and Immunologic Effects of Inhaled Fluticasone Propionate in Healthy Dogs

Abstract

Background: Inhaled glucocorticoids reduce airway inflammation while minimizing systemic effects in several species. Hypothesis: Inhaled fluticasone suppresses the hypothalamic-pituitary-adrenal axis (HPAA), modifies immune function, and induces clinical signs to a lesser extent than PO-administered prednisone in dogs.Animals: Seven healthy adult pet dogs. Methods: Dogs were randomized to 1 of 3 treatment groups in a crossover design: fluticasone propionate (220 mg actuation of a metered dose inhaler delivered via a spacer and mask, q12h), placebo (spacer and mask alone, q12h), or prednisone (1 mg/ kg PO q24h). Each treatment was administered for 3 weeks followed by a 4-week washout. Appetite, attitude, and water consumption were recorded during the last week of each treatment period. Urine cortisol : creatinine ratios, ACTH stimulation tests, white blood cell counts, lymphocyte phenotype, and serum IgM and IgA concentrations were recorded at each baseline and after the last day of each treatment. Clinical observations were expressed descriptively. Friedman's test was applied to all data comparisons. Pairwise comparisons were made with a mixed model analysis when data were normally distributed, whereas signed rank tests were used otherwise (significance P-value o.01).Results: Appetite and water consumption increased during prednisone treatment. Peak serum cortisol concentrations post-ACTH were significantly decreased in prednisone-and fluticasone-treated dogs compared with placebo (prednisone 4 fluticasone). Serum IgM concentrations were significantly decreased in dogs treated with prednisone.Conclusions and Clinical Importance: As used, fluticasone suppresses the HPAA to a lesser extent than prednisone and may avert systemic signs associated with PO-administered glucocorticoids in dogs.

A retrospective study of dogs with atypical hypoadrenocorticism: a diagnostic cut‐off or continuum?

“…This is a limitation of the study, because we cannot estimate with high accuracy what portion of the healthy dog population would be expected to have post-ACTH stimulation cortisol concentrations below the reference intervals provided by the laboratories. However, we identified several publications that used the Immulite® chemiluminescent assay (Siemen) in small numbers of healthy dogs (n≤20) and reported comparable ranges (Singh et al 1997, Cohn et al 2008, Lathan et al 2008, Ginel et al 2012). …”

ACVIM consensus statement guidelines for the diagnosis, classification, treatment, and monitoring of pulmonary hypertension in dogs

“…In group 3a disorders, recommended treatment is primarily symptomatic and includes cough suppression, sedation, oxygen supplementation, and, when present, control of secondary infection and inflammation. Specific examples may include, but are not limited to, glucocorticoids, opioids or other sedatives, antimicrobials, and antitussives . For management of severe tracheal collapse, placement of an intraluminal stent can be considered …”

Glucocorticoid Therapy

“…Ototopical administration of therapeutic doses of dexamethasone-containing ointment daily to healthy dogs resulted in HPA axis suppression within 11 days (Abraham et al, 2005). Inhaled fluticasone in healthy dogs and inhaled flunisolide in healthy cats suppressed the HPA axis within 2 to 3 weeks (Reinero et al, 2006;Cohn et al, 2008). Oral budesonide in dogs with IBD resulted in significantly lower post-ACTH cortisol concentrations after 30 days of therapy (Tumulty et al, 2004).…”