bronchodilator
A bronchodilator opens up tightened airways so air can flow more freely, the way loosening a kinked hose lets water run again. In asthma or COPD the muscle around the airways contracts and narrows them; a bronchodilator relaxes that muscle to ease breathing and wheezing.
There are three main classes. Beta-2 agonists (salbutamol, formoterol) relax airway smooth muscle by activating beta-2 receptors. Antimuscarinic agents (ipratropium, tiotropium) block the parasympathetic signal that constricts airways. Methylxanthines such as theophylline have a weaker, more old-fashioned role. Bronchodilators come in short-acting forms for quick relief and long-acting forms for maintenance, and are usually delivered straight to the lungs by inhaler to act fast with fewer body-wide effects.
Bronchodilators relieve the muscle-tightening part of airway disease but do not treat the underlying inflammation, which is why in asthma they are paired with inhaled steroids rather than used alone. Over-reliance on a reliever inhaler is a warning sign of poorly controlled disease that needs review.
During an asthma flare a person inhales salbutamol and feels the chest tightness ease within minutes as the airways open.
Salbutamol is a short-acting beta-2 agonist used to quickly relieve bronchoconstriction.
Bronchodilators relax airway muscle but do not control the inflammation underlying asthma; relying on a reliever inhaler frequently signals undertreated disease.