They are not recommended for regular daily therapy, because of evidence that daily use of inhaled b 2 -agonists may lead to a deterioration in asthma control in many patients. Patients were allowed to use a supplementary b 2 -agonist as necessary for symptoms. The total average daily amount of b 2 -agonist was 2.9 and 10.0 puffs in the placebo and fenoterol groups respectively. Eight out of nine measures of asthma control were worse while the patients were receiving regular fenoterol as compared to placebo. Oral liquid and tablet formulations of b 2 -agonists are not recommended.
Higher doses are usually well tolerated.
They are very safe and have a role in some patients, particularly children , when they have been proven effective in a therapeutic trial. In moderate to severe asthma, however, they are not generally as effective as inhaled corticosteroids. They have no role in managing acute exacerbations of asthma. Two randomized-controlled trials have shown superior control with the addition of salmeterol compared to doubling the dose of inhaled corticosteroids. Patients taking this medication should be carefully monitored and warned not to discontinue their maintenance anti-inflammatory therapy.