Beta 2 adrenergic agonists, especially in aerosol formulations, are often used as first-line medications for treating the symptoms of bronchial asthma. Although oral forms of these medications may result in greater improvement in small airway function, comparative studies of these two routes of administration show that inhaled beta 2 adrenergic bronchodilators have a more rapid onset of activity, are as long lasting, and as effective in improving pulmonary function as their oral forms. Moreover, they are equally effective at much lower dosages which results in fewer adverse effects. Their use in metered-dose inhalers, nebulizers, and breath-activated devices, is improving asthma therapy.