bronchodilatator

A bronchodilator is a medication designed to relax the smooth muscle in the walls of the airways, thereby widening the bronchi and reducing airflow resistance. These drugs are central to the treatment of obstructive airway diseases such as asthma and chronic obstructive pulmonary disease (COPD). They are used for both immediate relief of acute bronchospasm and long-term maintenance therapy, depending on the agent and the condition.

Bronchodilators work through several mechanisms. Short-acting beta-2 agonists (SABA), such as albuterol (salbutamol), rapidly relax airway smooth muscle by stimulating beta-2 adrenergic receptors, increasing cyclic AMP. Long-acting beta-2 agonists (LABA), such as salmeterol and formoterol, provide prolonged bronchodilation but are generally used in combination with anti-inflammatory therapy and not for sole relief of acute symptoms. Anticholinergic agents, including ipratropium and tiotropium, block muscarinic receptors to prevent acetylcholine-induced bronchoconstriction, useful in COPD and certain asthma cases. Methylxanthines like theophylline are older, orally administered agents with bronchodilatory effects but a narrow therapeutic window and more interactions. Phosphodiesterase inhibitors, including roflumilast, have anti-inflammatory actions and may complement bronchodilation in COPD.

Administration is most commonly via inhalation (metered-dose inhalers, dry powder inhalers, or nebulizers), delivering medication directly to the airways with rapid onset and fewer systemic effects. Some agents are available orally or intravenously for specific situations, such as severe exacerbations or when inhalation is not feasible.

Common side effects vary by class and can include tachycardia, tremor, dry mouth, or nausea. Bronchodilators require careful dosing and monitoring, particularly in patients with cardiovascular disease, glaucoma, or other comorbidities. Proper inhaler technique and adherence to prescribed regimens are essential for effectiveness.