Lower-dose prescribing: minimizing "side effects" of pharmaceuticals on society and the environment.

The prescribed use of pharmaceuticals can result in unintended, unwelcomed, and potentially adverse consequences for the environment and for those not initially targeted for treatment. Medication usage frequently results in the collateral introduction to the environment (via excretion and bathing) of active pharmaceutical ingredients (APIs), bioactive metabolites, and reversible conjugates. Imprudent prescribing and non-compliant patient behavior drive the accumulation of unused medications, which pose major public health risks from diversion as well as risks for the environment from unsound disposal, such as flushing to sewers. The prescriber has the unique wherewithal to reduce each of these risks by modifying various aspects of the practice of prescribing. By incorporating consideration of the potential for adverse environmental impacts into the practice of prescribing, patient care also could possibly be improved and public health better protected. Although excretion of an API is governed by its characteristic pharmacokinetics, this variable can be somewhat controlled by the prescriber in selecting APIs possessing environment-friendly excretion profiles and in selecting the lowest effective dose. This paper presents the first critical examination of the multi-faceted role of drug dose in reducing the ambient levels of APIs in the environment and in reducing the incidence of drug wastage, which ultimately necessitates disposal of leftovers. Historically, drug dose has been actively excluded from consideration in risk mitigation strategies for reducing ambient API levels in the environment. Personalized adjustment of drug dose also holds the potential for enhancing therapeutic outcomes while simultaneously reducing the incidence of adverse drug events and in lowering patient healthcare costs. Optimizing drug dose is a major factor in improving the sustainability of health care. The prescriber needs to be cognizant that the "patient" encompasses the environment and other "bystanders," and that prescribed treatments can have unanticipated, collateral impacts that reach far beyond the healthcare setting.