RESUMEN
The "Drug Product Selection act of 1978" became effective in South Carolina on January 1, 1979. All written prescription forms must be printed with two signature lines. Under the line at the left, "DISPENSE AS WRITTEN" must be printed. Under the line at the right, "SUBSTITUTION PERMITTED" must be printed. In addition, the pharmacist must receive the patient's consent before substitution can occur. This study investigated the impact of the Act on physicians' prescribing habits and pharmacists' responses to drug product selection initially and 3 months after enactment. The data were analyzed according to the drugs prescribed, permitted substitutions, physicians' specialties, use of correct prescription blank, drug category, date, and drug actually dispensed. Physicians permitted substitution for 27.19 percent of all prescriptions written. There were 499 prescriptions out of 1,835 authorizing substitutions. A total of 127 of these drugs were for single-source items, as 162 were written for generic items. In the remaining 210 prescriptions for brand name items, pharmacists selected another brand only 24 percent of the time.