At 1 year, almost half of patients had quit taking prescribed antihypertensive medication.
Poor adherence to antihypertensive drug treatment is a major reason for insufficient blood pressure control. In this longitudinal study, investigators used data from 21 clinical studies to determine adherence among 4783 patients who were prescribed 1 of 43 once-daily antihypertensive drugs.
Adherence was determined using medication containers that electronically record the date and time of each opening. At 1 year, almost half the patients had stopped treatment altogether (nonpersistence). On any given day, about 10% of scheduled doses were missed (nonexecution). Overall, 95% of patients missed a single dose at least once yearly, half missed a single dose once monthly, and nearly half took drug holidays lasting longer than 3 days at least once yearly. Failure to execute was significantly more common between April and September and on weekends. Morning takers were significantly more likely to execute than evening takers. Patients with better execution were significantly more likely to persist taking the drug.
Comment: As the authors conclude, patients at risk for quitting medication need reinforcement to continue (unless the reason for quitting is an adverse effect of the drug), whereas those who execute poorly need help integrating dosing into their daily routines. These findings also suggest that medications should be taken in the morning and that barriers to execution during vacations and weekends should be addressed. Finally, these results suggest that, in patients with insufficiently controlled blood pressure, clinicians should first inquire about and address nonadherence before adding another drug to the patient’s regimen, which would make adherence only more difficult.
— Paul S. Mueller, MD, MPH, FACP
Published in Journal Watch General Medicine June 12, 2008
Vrijens B et al. Adherence to prescribed antihypertensive drug treatments: Longitudinal study of electronically compiled dosing histories. BMJ 2008 May 17; 336:1114.