Leukotriene receptor antagonists (LTRAs)

Leukotriene receptor antagonists (e.g. montelukast) act by blocking the inflammatory mediators (leukotrienes) through antagonism at their receptor site, resulting in less bronchoconstriction, reduced mucus secretion and eosinophil infiltration. In adults, the addition of LTRA to ICS as add-on therapy is superior to ICS alone and has a similar effect on asthma control to high-dose ICS. In children under five years who are unable to take ICS, leukotriene receptor antagonists may be used as an alternative preventer. If exercise is a specific problem in patients taking ICS, who are otherwise well controlled, LTRAs are one of the therapies that can be considered.

Theophylline

Modified release theophylline can be used as an additional add-on therapy in the treatment of asthma for adults and children. It has a narrow therapeutic range of 10-20mg/L, which can be affected by enzyme inhibitors and inducers, so blood plasma theophylline levels should be closely monitored. Prescribers should specify the brand on the prescription due to differences in bioavailability amongst the brands.

Cromones

Inhaled corticosteroids are the first choice preventer drug. Cromones, such as sodium cromoglicate and nedocromil sodium, are alternative, less effective preventer therapies for adults and children over five years of age taking short-acting beta2 agonists alone. Cromones can be considered as add-on treatments for asthma and patients should be advised that inhaled sodium cromoglicate or nedocromil sodium should be used regularly. If exercise is a specific problem in patients taking ICS who are otherwise well controlled, a cromone can be added into the management.