Inhaled Corticosteroids — Use & Administration
A patient uses albuterol daily but never started the inhaled corticosteroid that was prescribed. Their asthma keeps worsening — because rescue inhalers don't treat the underlying problem.
Core Concept
Inhaled corticosteroids (ICS) — including fluticasone, budesonide, and beclomethasone — are the cornerstone controller therapy for persistent asthma. They work by suppressing airway inflammation at the local level: ICS inhibit the release of inflammatory mediators (cytokines, leukotrienes, prostaglandins) and reduce mucosal edema, mucus hypersecretion, and bronchial hyperresponsiveness over time. This is NOT a rescue mechanism. ICS do not produce bronchodilation and will not relieve an acute attack. Onset of therapeutic benefit takes 1–2 weeks of consistent daily use, with maximum benefit at 4–8 weeks. The client must use ICS every day on schedule — even when feeling well — because the drug prevents inflammation rather than reversing it in the moment. ICS are also used as maintenance therapy in moderate-to-severe COPD, typically combined with a long-acting bronchodilator. When both a bronchodilator and ICS are prescribed via separate inhalers, the bronchodilator is used first to open airways, followed by the ICS so the steroid penetrates deeper into the lungs.
Watch Out For
Don't confuse controller therapy (ICS, taken daily to prevent symptoms) with rescue therapy (SABA like albuterol, used for acute bronchospasm). Students often think ICS work immediately — they don't; the 1–2 week delay is highly testable. Don't confuse inhaled corticosteroids with systemic corticosteroids like prednisone; ICS deliver medication locally with minimal systemic absorption, which is exactly why they're preferred for long-term use.
Clinical Pearl
Bronchodilator before corticosteroid — open the door, then deliver the medicine. And ICS every day, not just on bad days.
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