High vs. Low-Dose Inhaled Corticosteroids: Effects on Lung Function and Adverse Outcomes in Asthma

Objective To evaluate whether prolonged high-dose inhaled corticosteroids (ICS) confer clinically meaningful improvements in lung function compared with low-to-moderate doses in asthma, and to summarize the safety profile associated with higher ICS dosing. Methods We conducted a narrative review of the medical literature on ICS dosing in asthma, prioritizing recent studies. Eligible clinical trials and studies included patients with a clinical diagnosis of asthma receiving either high or low-doses of ICS; age and sex were not restricted. For mechanistic considerations where direct ICS data were limited, literature on systemic corticosteroids were used. Dose thresholds for low, medium, and high ICS were aligned with GINA classifications across formulations and devices. Results Across the reviewed evidence, high-dose ICS did not demonstrate consistent additional benefit in lung function or exacerbation reduction compared with low-to-moderate dosing. In contrast, prolonged high-dose use was associated with increased risk of adverse effects, including systemic corticosteroid–related effects, which were less frequent at lower doses. Conclusion For most patients with asthma, escalating to high-dose ICS offers limited incremental efficacy while increasing the likelihood of adverse events. When control is inadequate on low-to-moderate ICS, adding adjunct therapy such as a long-acting beta2-agonist or a leukotriene receptor antagonist is preferable to further ICS up-titration.