Editing Bronchodilator (section)

==Short-acting β<sub>2</sub>-adrenergic agonists==
These are quick-relief or "rescue" medications that provide quick, temporary relief from asthma symptoms or flare-ups. These medications usually take effect within 20 minutes or less, and can last from four to six hours. These inhaled medications are best for treating sudden and severe or new asthma symptoms. Taken 15 to 20 minutes ahead of time, these medications can also prevent asthma symptoms triggered by exercise or exposure to cold air. Some short-acting β-agonists, such as [[salbutamol]], are specific to the lungs; they are called β<sub>2</sub>-adrenergic agonists and can relieve bronchospasms without unwanted [[cardiac]] side effects of nonspecific β-agonists (for example, [[ephedrine]] or [[epinephrine]]). Patients who regularly or frequently need to take a short-acting β<sub>2</sub>-adrenergic agonist should consult their doctor, as such usage indicates uncontrolled asthma, and their routine medications may need adjustment.{{citation needed|date=February 2022}}