ATC Group: R03AC Selective beta-2-adrenoreceptor agonists

Clenbuterol is a direct-acting β2 sympathomimetic agent for the treatment of chronic obstructive airway diseases.

Formoterol is a predominantly selective β₂-stimulator. Formoterol has bronchodilator activity in patients with reversible obstructive airway diseases. In humans formoterol is effective in the prophylaxis of bronchospasm induced by methacholine challenge.

Indacaterol is a partial agonist at the human beta₂-adrenergic receptor with nanomolar potency. When inhaled, indacaterol acts locally in the lung as a bronchodilator. In isolated human bronchus, indacaterol has a rapid onset of action and a long duration of action.

Olodaterol has a high affinity and high selectivity to the human beta₂-adrenoceptor. The compound exerts its pharmacological effects by binding and activation of beta₂-adrenoceptors after topical administration by inhalation. Activation of these receptors in the airways results in a stimulation of intracellular adenyl cyclase, an enzyme that mediates the synthesis of cyclic-3',5' adenosine monophosphate (cAMP). Elevated levels of cAMP induce bronchodilation by relaxation of airway smooth muscle cells.

Procaterol is an intermediate-acting β2 adrenoreceptor agonist used for the treatment of dyspnea caused by bronchial asthma, chronic bronchitis, and pulmonary emphysema.

Salbutamol is a selective β₂-agonist providing short-acting (4-6 hour) bronchodilation with a fast onset (within 5 minutes) in reversible airways obstruction. At therapeutic doses it acts on the β₂-adrenoceptors of bronchial muscle. Salbutamol is administered for the symptomatic relief of bronchospasm associated with chronic or acute asthma, bronchitis or other obstructive pulmonary diseases.

Salmeterol is a selective long-acting (12 hour) β₂ adrenoceptor agonist. These pharmacological properties of salmeterol offer more effective protection against histamine-induced bronchoconstriction and produce a longer duration of bronchodilation, lasting for at least 12 hours, than recommended doses of conventional short-acting β₂ agonists.

Terbutaline is a selective beta₂-adrenoceptor agonist, thus producing relaxation of bronchial smooth muscle, inhibition of the release of endogenous spasmogens, inhibitions of oedema caused by endogenous mediators, increased mucociliary clearance and relaxation of the uterine muscle.