Controller medicines help reduce the swelling in your airways to prevent asthma attacks.

Controller medicines include inhaled corticosteroids (some brand names: Azmacort, AeroBid, Flovent, etc.), cromolyn (one brand name: Intal) and nedocromil (brand name: Tilade).

Newer medicines, called anti-leukotrienes, are also used to prevent asthma attacks. These include montelukast (brand name: Singulair), zafirlukast (brand name: Accolate) and zileuton (brand name: Zyflo).

Controller medicines must be taken on a regular basis–whether or not you’re having symptoms. They take hours or days to start to help and don’t work well unless you take them regularly.