Asthma & COPD Drugs: Relievers vs Controllers

Airway disease has two problems — bronchoconstriction (tight muscle) and inflammation (swollen, mucus-filled airway). So the drugs split into two camps: relievers that open the airway fast, and controllers that calm the inflammation over time.

Relievers (bronchodilators)

• SABA — salbutamol: the rescue inhaler; fast relief of acute bronchospasm. Side effects: tremor, tachycardia, hypokalaemia.
• LABA — salmeterol, formoterol: long-acting; never used alone in asthma — always with an inhaled steroid.
• Antimuscarinics — ipratropium (short), tiotropium (long): block M3 receptors; tiotropium is a mainstay of COPD.
• Theophylline: oral bronchodilator with a narrow therapeutic index — interactions and toxicity (arrhythmia, seizures) limit its use.

Controllers (anti-inflammatory)

• Inhaled corticosteroids (ICS): the cornerstone of asthma management — reduce airway inflammation and exacerbations. Rinse the mouth to avoid oral thrush and dysphonia.
• Leukotriene receptor antagonists (montelukast): oral, useful in allergic and exercise-induced asthma.
• Biologics: omalizumab (anti-IgE) and anti-IL-5 agents for severe eosinophilic/allergic asthma.

Asthma vs COPD — the key difference

• Asthma is reversible and inflammation-driven → ICS is essential; reliever alone is never enough.
• COPD is largely fixed → LAMA/LABA bronchodilators lead; ICS is reserved for frequent exacerbators (eosinophilic).

Acute severe asthma — the emergency

Remember “OSHA”: Oxygen, Salbutamol (nebulised), Hydrocortisone/steroids, Anticholinergic (ipratropium) — add magnesium sulfate if severe.

Exam tip: the single most-tested rule here — a LABA must never be given alone in asthma (increased mortality); always pair it with an inhaled corticosteroid. And ICS is the controller that actually changes the disease.

Split every airway drug into reliever or controller, then match the strategy to the disease — ICS-led for asthma, bronchodilator-led for COPD — and you’ll prescribe (and answer) with confidence.