Bronchodilator

Each airway is encircled by a ring of smooth muscle. In asthmaAsthmaAsthma is a long-term condition in which the airways are inflamed and tighten in response to triggers, causing wheeze, cough, chest tightness and breathlessness that come and go. It is controllable in almost everyone with the right treatment used correctly.Read the full definition and in COPD that muscle contracts and the tube narrows, so the same breath moves less air. A bronchodilator switches the muscle off. Salbutamol, the blue reliever inhaler, is the one almost everyone means by the word; ipratropium works by a different receptor and is often combined with it in a nebuliser.

Short-acting and long-acting

• Short-acting — salbutamol and ipratropium. They work within about five minutes and last four to six hours. This is the medicine for an attack and the one to carry.
• Long-acting — salmeterol, formoterol, tiotropium, indacaterol. They last twelve to twenty-four hours and are taken on a fixed schedule for background control. They are not for rescue, with the partial exception of formoterol in the combination regimens now recommended in asthma.
• Combination inhalers pair a long-acting bronchodilator with an inhaled corticosteroidCorticosteroidCorticosteroids are medicines related to cortisol, the body's own stress hormone, and they are the most powerful suppressors of inflammation in general use. They are not the muscle-building steroids of the gym, which are a different class of drug entirely.Read the full definition. In asthma a long-acting bronchodilator must never be used without that steroid.
• Oral and injected forms exist, including aminophylline, but the inhaled route delivers more medicine to the airway with a fraction of the side effectSide effectA side effect is any effect of a medicine other than the one it was given for. Some are trivial and settle, some are the reason a medicine has to be stopped.Read the full definition burden.

A racing heart, a fine tremor of the hands and restlessness for half an hour after a dose are expected effects rather than an allergy, and they fade. Two things to watch: needing a reliever more than twice a week means the underlying condition is not controlled and the preventer needs reviewing, not the reliever increasing; and a reliever that stops working in an attack is an emergency. Almost all of the benefit depends on technique, so use a spacer with a metered-dose inhalerInhalerAn inhaler delivers medicine as a spray or powder directly into the airways, where a very small dose does the work of a much larger tablet with far fewer effects on the rest of the body. How it is used decides how well it works.Read the full definition and have the method checked at least once a year.