Variability in Drug Administration Times among Patients with Coronary Artery Disease

Abstract

Objective:

Previous studies have shown that cardiac disease is influenced by circadian rhythms, resulting in a high incidence of cardiac events occurring in the morning hours. Before determining if adjusting drug administration times will influence the effect of these circadian rhythms, it is necessary to know when patients take their medication. Therefore, the objective of this study was to determine when patients take their anti-ischemic medication in relationship to their sleep/wake cycle.

Design:

Patients with a history of coronary artery disease were identified by screening consecutive medical charts from a cardiology outpatient clinic at a university teaching hospital. Data were collected by telephone interview with a survey instrument.

Participants:

A total of 57 patients were included in the study (41 men, mean age 61.8 ± 10 years; and 16 women, mean age 62.8 ± 10.4 years).

Outcome Measures:

The survey addressed the relationship between sleep/wake cycle and medication administration times, along with activities performed prior to taking morning medication.

Results:

Approximately 46 percent of the patients took their anti-ischemic medication upon awakening and 28 percent of the patients took their anti-ischemic medication more than 30 minutes after awakening. Of the 31 patients requiring evening dosing of their anti-ischemic medication, 45 percent took their medication at bedtime and 39 percent of the patients took their medication more than three hours before bedtime. Major activities patients undertook prior to taking their morning medications included urination/defecation, eating breakfast, and getting dressed.

Conclusions:

This study showed that there is variability in the time of drug administration among cardiac patients, which may be important regarding circadian variation and cardiac disease. Additional counseling by pharmacists in regard to drug administration times and circadian rhythms may be warranted following further studies.