Background Inhaled or nasal corticosteroids can cause suppression of the hypothalamic-pituitary-adrenal (HPA) axis. Early detection is important because this suppression can be associated with significant morbidity. Objective To explore the adverse effect of hypothalamic-pituitary-adrenal suppression by local corticosteroids in HIV-infected patients. Method Ambulatory HIV-infected patients were selected if they used both antiretroviral treatment and inhaled or nasal corticosteroid. Suppression of hypothalamic-pituitary-adrenal axis was defined as a morning plasma cortisol below 80 nmol/L or a cortisol below 550 nmol/L during a 250 mcg adrenocorticotropic hormone-stimulation test. Results Twelve patients were tested; four of them were taking a CYP3A4 inhibitor. All patients had a normal morning plasma cortisol. Suppression of the hypothalamic-pituitary-adrenal axis during the ACTH stimulation test was identified in three of the twelve patients. None of these three individuals were taking a CYP3A4 inhibitor. Conclusion Hypothalamic-pituitary-adrenal axis suppression is frequently identified in patients on inhaled or nasal corticosteroids. CYP3A4 inhibitors such as ritonavir or cobicistat may increase the chance of this adverse effect. In this study we did not identify HPA axis suppression in patients taking CYP3A4 inhibitors. This may be related to the fact that 2 of these 4 patients used beclomethasone, a corticosteroid not metabolized by CYP3A4.ClinicalTrials.gov Identifier NCT02501486.