Long-term studies on long-acting sympathomimetics.

Long-term treatment studies with formoterol and salmeterol show that these inhaled long-acting beta 2-agonists compared to available beta 2-agonists produce better bronchodilation, decrease the need for additional doses, decrease asthma symptoms, and are strongly preferred by the patients. Development of tolerance has not been found. One case history indicates that these effective bronchodilators might mask deterioration of asthma.