Effect of intranasal dexamethasone on endogenous cortisol level and intraocular pressure

Background: Medical treatment of chronic rhinosinusitis with nasal polyposis (CRSwNP) centers on the administration of steroids. High-dose topical nasal steroids (HDTNS) have shown promising results with less systemic effects than oral steroids. One promising HDTNS is 0.132% dexamethasone nasal spray. We investigated whether intranasal dexamethasone was associated with changes in serum cortisol and/or intraocular pressure (IOP). Methods: Patients with CRSwNP were treated with dexamethasone sodium phosphate 0.132% nasal spray twice daily. Morning serum cortisol and IOP were checked after at least 6 weeks of therapy. Results: Twenty-eight patients met study criteria. The average serum cortisol level after at least 6 weeks of therapy (average duration of 38.3 weeks) was 9.8 μg/dL (normal range, 4 to 22 μg/dL). Ten patients had suppressed cortisol levels (average, 2.5 μg/dL). Ten patients underwent IOP measurements and none revealed ocular hypertension on tonometry. Conclusion: High-dose dexamethasone nasal spray given for a period of at least 6 weeks does appear to have the potential to cause a decrease in serum cortisol levels; however, future studies with greater power are necessary to support this claim. Additionally, similar administration of high-dose dexamethasone nasal spray did not reveal IOP diagnostic of ocular hypertension on single-measurement tonometry readings.