Optimal time to take once-daily oral medications in clinical practice.

Currently only a few package inserts of once-daily medications specially define the dosing time, although sporadic studies have demonstrated administration time-dependent effects on the therapeutic outcome. Some chronotherapeutic approaches aim to diminish the occurrence of adverse drug reactions (ADRs) and hence better tolerance and medication compliance whereas most of the chronotherapies are recommended to improve therapeutic efficacy. The administration time-dependent efficacy seems not a common feature of drugs within the similar therapeutic or structural class and it is related to kinds of drugs, pathophysiologic status, clinical symptoms and feedback from patients. Doctors, pharmacists and nurses should know what kind of drug has requirement for optimal dosing time, and realize that better efficacy and lower incidence of ADRs may be achieved by rational arrangement of administration schedule. In order to promote medication compliance, it is essential to provide patient education regarding differences between conventional and chronotherapeutic approaches and pathophysiologic benefits of chronotherapy.