Respiratory
Asthma, COPD, allergy and the airways — inhalers, bronchodilators, steroids and the drugs that help you breathe.
Foundations
How the airways work, why we inhale drugs, and the devices that get them to the lungs.
Bronchodilators
Opening the airways — beta-2 agonists and antimuscarinics, and asthma versus COPD.
Anti-inflammatory Controllers
Calming the underlying inflammation — inhaled steroids, leukotriene drugs, and biologics.
Acute Care & Support
The acute attack, oxygen and respiratory failure, and the pharmacology of quitting smoking.
Allergy & Upper Airway
Antihistamines and allergic rhinitis, anaphylaxis, and the drugs for cough, cold and mucus.
Specialized Lung Disease
Cystic fibrosis, pulmonary hypertension, and pulmonary fibrosis — the specialist end of lung pharmacology.
How the Airways Work — and Why We Inhale the Drug
Almost every drug in this section is breathed in rather than swallowed, and that isn't an accident — it's the single most important idea in respiratory pharmacology. Understand what narrows an airway and why we deliver the drug straight to the lungs, and every inhaler, bronchodilator and steroid that follows will make immediate sense.
Inhalers & Devices: Getting the Drug to the Lungs
The best asthma drug in the world is useless if it never reaches the lungs — and studies show a large fraction of patients use their inhaler wrong. This is the most practical topic in respiratory medicine: knowing the device types, why a spacer helps so much, and the small habits that make the difference between a drug that works and one that doesn't.
Asthma vs COPD: One Reverses, One Doesn't
Asthma and COPD both cause breathlessness, wheeze and cough from narrowed airways — yet they are fundamentally different diseases, and one single distinction drives almost all of their treatment. Get that distinction clear and you'll instantly understand why steroids are central to one and bronchodilators to the other.
Beta-2 Agonists: The Blue Inhaler That Opens the Airway
The blue reliever inhaler that millions of people carry is a beta-2 agonist — and it's a perfect payoff from the autonomic nervous system chapter. It relaxes airway muscle by triggering the same 'fight or flight' receptor that widens your airways when you run. Understanding that one receptor explains how the drug works, why it comes in fast and slow versions, and where its side effects come from.
Antimuscarinic Bronchodilators: Opening the Airway the Other Way
There are two ways to relax airway muscle: switch on the 'open' signal, or switch off the 'close' signal. Beta-2 agonists do the first; antimuscarinics do the second — by blocking the parasympathetic nerve that keeps airways tight. They're a second pillar of bronchodilation, especially important in COPD, and another direct payoff from the autonomic chapter.
