Costs and benefits in switching from Rx to OTC.

This paper contains an initial inquiry into the benefits and costs of switching some drugs from prescription-only (Rx) status to over-the-counter (OTC) status. It contributes to a discussion of the Food and Drug Administration (FDA) policy of making this change for selected drugs, such as chlorpheniramine (switched in 1976) and topical hydrocortisone (switched in 1979). Costs and benefits are estimated for three representative drugs: (1) topical hydrocortisone, a medicine with limited use and side effects; (2) thiazide diuretics, drugs used on a continuing basis to treat chronic conditions; (3) and oral penicillin, a well-understood anti-infective agent. The purpose of the calculations is to suggest criteria for deciding which drugs could be switched. Reasonably potent drugs are considered to assess the limits of switching policy.