Which class of medication is contraindicated in patients with a history of asthma?

Beta blockers are contraindicated in patients with a history of asthma due to their potential to cause bronchoconstriction. These medications work primarily by blocking the beta-adrenergic receptors in the body, including those in the lungs. In asthmatic patients, where airway constriction is already a concern, the use of non-selective beta blockers can exacerbate respiratory conditions by inducing bronchospasm and limiting airflow.

These patients may be prescribed selective beta-1 blockers when absolutely necessary, but caution is exercised even with these due to the potential for cross-reactivity. On the other hand, other classes like prostaglandins, alpha agonists, and carbonic anhydrase inhibitors do not have the same constricting effect on bronchial airways and are generally considered safer for individuals with asthma. Thus, the use of beta blockers in asthmatic patients poses significant risks and is why they are deemed contraindicated in this specific population.