Influencing drug use through prescribing restrictions.

The effect of several drug restriction policies on benzodiazepine and cephalosporin use was evaluated in a large federal hospital. Computerized drug-use data were examined for the 10-year period from 1972 through 1981. The five major types of drug restrictions implemented were the: (1) requirement that all diazepam prescriptions be countersigned by the chief of staff, (2) deletion of cephalothin sodium from the formulary, (3) required countersignature by a physician from the infectious disease service for all cefazolin sodium prescriptions, (4) requirement that justification accompany all cefazolin sodium prescriptions after the countersignature requirement was lifted, and (5) amendment of the countersignature requirement for diazepam with a series of designated exceptions. All of the restrictions resulted in a decrease in the number of dosage units dispensed; however, the required countersignature by the chief of staff and deletion from the formulary were the most effective in restricting drug use. The effect of the restriction policies appears to be related to the influence or power of the restriction enforcer and the perceived importance of the restriction, as well as the relative difficulty of drug acquisition by the prescriber. Formulary deletion, countersignature requirements, or restricted use to a service or physician are action plans that may alter the use rates of drugs.