Trends in asthma and chronic obstructive pulmonary disease therapy in Canada, 1985 to 1990

In the mid and late 1980s, numerous changes were recommended in the management of obstructive lung diseases. We analyzed drug sales to determine whether these recommendations have resulted in recent changes in prescription drugs used in airway management.

Data on prescription sales in Canada from 1985 to 1990 were obtained from an international pharmaceutical market research organization. Data from a random sampling of physicians that reported patients seen along with the diagnosis and prescriptions given were also reviewed.

From 1985 to 1990, there was a 38% increase in prescriptions of all airway drugs. Prescriptions increased significantly for inhaled drugs as follows: inhaled beta 2-agonists, 70%; inhaled steroids, 139%; cromoglycate, 88%; and ipratropium bromide, 204%. Theophylline prescriptions, by contrast, fell significantly, by 19%. Although theophylline was the most commonly prescribed airway medication in 1985, inhaled beta 2-agonists were the most commonly prescribed drug in 1990, and these changes in proportional use were significant. Increases in ipratropium bromide usage was accounted for by increases in prescriptions for chronic obstructive pulmonary disease. Increases in nonsteroidal antiinflammatory drugs were accounted for by asthma prescriptions.

The increase in airway medication prescriptions dispensed in Canada is consistent with an increase in the number of patients treated, an increase in the severity of disease treated, or both.