Salmeterol xinafoate: a review of its pharmacological properties and therapeutic potential in reversible obstructive airways disease.

Salmeterol xinafoate, like salbutamol (albuterol), is a saligenin derivative, and a selective beta 2-adrenoceptor agonist. It produces bronchodilation for at least 12 hours following inhalation of a single 50 micrograms dose. Salmeterol is intended for regular twice-daily treatment of reversible airways obstruction and not for immediate symptomatic relief, and when used in this manner. 50 micrograms twice daily is more effective than salbutamol 200 micrograms or terbutaline 500 micrograms administered 4 times daily, or individually titrated oral doses of theophylline in improving objective and subjective criteria of efficacy in patients with mild to moderate asthma. Salmeterol 100 micrograms inhaled twice daily may provide better control than the lower dose in patients with severe asthma. The long duration of effect of salmeterol makes it particularly suitable for treating patients with nocturnal asthma in whom it improves sleep quality. The place of salmeterol, like that of other beta 2-adrenoceptor agonists used regularly in the treatment of asthma, is being debated. Patients in need of regular beta 2-agonist therapy should also be regarded as candidates for inhaled corticosteroids to counteract underlying inflammation. Thus, salmeterol may be particularly useful in patients requiring regular treatment with beta 2-agonists for nocturnal asthma and results of trials in progress involving large numbers of patients are awaited with interest.