The average annual expenditure on asthma medications for U.S. children rose from $527 million in 1997-1998 to almost $2.5 billion in 2007-2008, an increase of 367%, according to a report from the Agency for Healthcare Research and Quality.

The increase was driven almost entirely by spending on asthma controller medications, which increased by 651% from 1997-1998 to 2007-2008. (See graph, below.) The average annual proportion of children who were treated for asthma rose from 4.7% to 6.1% in the time period studied, the report noted.

Of the four classes of controllers, average annual use among pediatric patients increased for three: Inhaled corticosteroid use went from 15.5% in 1997-1998 to 40.3% in 2007-2008, inhaled long-acting beta-agonist use rose from 3.0% to 13.2%, and leukotriene receptor antagonist use went from 2.9% to 34.1%. The proportion of children using nonsteroidal antiallergy agents dropped from 15.1% in 1997-1998 to 0.6% in 2007-2008, the AHRQ said.