Salbutamol
Salbutamol, also known as albuterol and sold under the brand name Ventolin among others, is a medication that opens up the medium and large airways in the lungs. It is a short-acting β2 adrenergic receptor agonist which works by causing relaxation of airway smooth muscle. It is used to treat asthma, including asthma attacks and exercise-induced bronchoconstriction, as well as chronic obstructive pulmonary disease (COPD). It may also be used to treat high blood potassium levels. Salbutamol is usually used with an inhaler or nebulizer, but it is also available in a pill, liquid, and intravenous solution. Onset of action of the inhaled version is typically within 15 minutes and lasts for two to six hours. Common side effects include shakiness, headache, fast heart rate, dizziness, and feeling anxious. Serious side effects may include worsening bronchospasm, irregular heartbeat, and low blood potassium levels. It can be used during pregnancy and breastfeeding, but safety is not entirely clear. Salbutamol was patented in 1966 in Britain and became commercially available in the UK in 1969. It was approved for medical use in the United States in 1982. It is on the World Health Organization's List of Essential Medicines. Salbutamol is available as a generic medication. In 2020, it was the seventh most commonly prescribed medication in the United States, with more than 61 million prescriptions. Salbutamol is typically used to treat bronchospasm (due to any cause—allergic asthma or exercise-induced), as well as chronic obstructive pulmonary disease. It is also one of the most common medicines used in rescue inhalers (short-term bronchodilators to alleviate asthma attacks). As a β2 agonist, salbutamol also has use in obstetrics. Intravenous salbutamol can be used as a tocolytic to relax the uterine smooth muscle to delay premature labor. While preferred over agents such as atosiban and ritodrine, its role has largely been replaced by the calcium channel blocker nifedipine, which is more effective and better tolerated.