Medication timing for the elderly: the impact of biorhythms on effectiveness.

The concept of chronopharmacology has significant implications for drug delivery systems. Age and illness put the elderly at greater risk for adverse drug effects, and nurses caring for the elderly have a challenging opportunity to measurably improve the quality of their care by applying chronotherapeutic concepts. Pharmacologic chronotherapy is a developing science that holds much hope for increasing the effectiveness of drug therapy and for reducing the incidence of toxic drug reactions. Nurses who are aware of the principles on which chronotherapy is based are in a unique position to improve the effectiveness of pharmacotherapy for all clients. However, appropriate timing of medications is especially important among elderly clients whose physiological processes are altered or changed by age and chronic illness. In this article, the basis of chronotherapy is discussed, and several therapeutic applications are identified.