The use of first- and second-line outpatient antibiotics under the Saskatchewan Drug Plan.

The Saskatchewan Drug Plan proposed de-listing several second-line antibiotics from its formulary for reasons of potential overuse and expense. This study evaluated the use of second-line antibiotics as initial and secondary courses of therapy depending on the patient's prior use of other antibiotics and other factors. A total of 637,607 courses of therapy dispensed to Plan members for selected antibiotics between July 1989 and June 1990 were evaluated. Second-line antibiotics were used in 5.0% of all initial courses of therapy. This use was correlated with patient characteristics that may warrant use of second-line antibiotics as initial therapy: age, rural residence, the use of bronchodilators or inhaled steroids, and the number of prior courses of antibiotic therapy. The potential savings from de-listing second-line antibiotics from the formulary are limited because of their use in only 5% of all initial courses of therapy. Savings would be further reduced by administrative costs and physician time required to process prior authorisation requests, and the costs of treating any additional antibiotic treatment failures that may result from reduced access.