Do inhaled corticosteroids (ICS) have long-term effects on adults with asthma?

Long-Term Effects of Inhaled Corticosteroids in Adults with Asthma

Inhaled corticosteroids (ICS) are remarkably safe for long-term use in adults with asthma when used at recommended doses, with minimal systemic effects that are far outweighed by the benefits of controlling persistent asthma. 1, 2

Local Effects (Most Common)

The most frequently encountered adverse effects are localized to the oropharynx and are easily managed:

• Oral candidiasis (thrush) is the most common local side effect, occurring primarily with higher doses 3, 4
• Dysphonia (hoarseness) and voice changes occur but cause no significant morbidity 4, 5
• These local effects can be minimized by rinsing the mouth after each use, using spacers with metered-dose inhalers, and ensuring proper inhaler technique 1, 3

Systemic Effects (Dose-Dependent)

While concerns exist about systemic effects, the evidence shows these are minimal at recommended doses:

Adrenal Suppression

• Changes in adrenal function have been noted only with doses exceeding 1,500 mcg/day of beclomethasone or budesonide 4
• The clinical relevance of these biochemical changes remains unclear, and clinically significant adrenal suppression is rare with inhaled therapy 3, 4
• Morning plasma cortisol or 24-hour urinary cortisol testing should be considered only if there is clinical concern for hypothalamic-pituitary-adrenal axis suppression 1

Bone Mineral Density

• Short-term and cross-sectional studies have shown changes in biochemical markers of bone turnover, and some retrospective studies found reduced bone density in asthmatics treated regularly with ICS 4
• However, bone densitometry (DEXA scan) is recommended only for patients on high-dose ICS for more than 1 year or those receiving frequent oral corticosteroid courses, particularly perimenopausal women 1
• The risk of bone effects increases significantly with high doses and prolonged use 3

Ocular Effects

• Posterior subcapsular cataracts are a potential concern with long-term high-dose ICS use 3
• Slit-lamp eye examination should be performed for patients on high-dose ICS for more than 1 year or those receiving frequent oral corticosteroid courses 1
• Reports on increased cataract formation are difficult to interpret due to confounding factors, including concurrent or prior oral corticosteroid use 4

Growth in Children (Not Applicable to Adults)

• While one-year studies show decreased growth velocity in children, long-term studies with budesonide and beclomethasone demonstrate no effect on final adult height 2
• Most children treated with ICS achieve their predicted adult heights, although temporary growth delay may occur 3

Critical Safety Context

The evidence consistently demonstrates that ICS do not alter the progression or underlying severity of asthma, but they remain the most effective therapy for controlling symptoms, improving lung function, and preventing exacerbations 6, 5

Key Safety Principles:

• ICS should always be used at the lowest dose compatible with disease control to minimize any potential adverse effects 4, 3
• It is as important to step down medication in well-controlled patients as it is to step up in uncontrolled patients, balancing benefits against risks 3
• Low-dose ICS are generally safe, but adverse effects increase significantly with high doses and prolonged use 3

Evidence Quality and Strength

The guideline evidence strongly supports ICS safety:

• ICS are the most consistently effective long-term control medications at all steps of care for persistent asthma in both children and adults 6, 1
• They improve asthma control more effectively than leukotriene receptor antagonists or any other single long-term control medication 6
• The benefits of ICS therapy clearly outweigh the risks of uncontrolled asthma, and ICS should be prescribed routinely as first-line therapy for adults with persistent disease 2

Common Pitfalls to Avoid

• Never discontinue ICS abruptly in patients with moderate-to-severe asthma, as this increases risk of exacerbations 6
• Patient concerns about long-term corticosteroid use can affect adherence—appropriate education about the safety profile of inhaled versus oral corticosteroids is essential 3
• Do not use high-dose ICS when combination therapy (ICS plus long-acting beta-agonist) would be more appropriate, as this exposes patients to unnecessary systemic effects 6, 7

Monitoring Recommendations

For patients on long-term ICS therapy:

• Assess inhaler technique and adherence at every visit 1
• Consider bone densitometry and ophthalmologic examination only for those on high-dose ICS (>1 year) or frequent oral corticosteroid courses 1
• Reassess asthma control every 2-4 weeks after treatment changes, and consider stepping down therapy if well-controlled for 2-4 months 1, 8