Asthma treatment in the 21st century: what's next?

Asthma treatment is evolving as we enter the 21st century. This review focuses on several different areas of asthma treatment now in evolution. These include: (1) the proper role of various asthma controllers--either already approved or under investigation--besides inhaled corticosteriods in asthma therapy; (2) the potential role for immune and cytokine modulation for asthma therapy; (3) the potential role for pharmacogenetics in asthma therapy; and (4) whether single-inhaler therapy with a combination of an inhaled corticosteriod and a long-acted beta-agonist could be used for both maintenance and rescue in patients with asthma.