Foot volume increase on nifedipine is not prevented by pretreatment with diuretics

Polytherapy with two or more antihypertensive drugs to lower blood pressure in elderly Ontarians. Room for improvement

BACKGROUND

Although guidelines now recommend polytherapy to achieve blood pressure targets, little is know about which antihypertensive drugs are combined in clinical practice.

OBJECTIVE

To examine current practices for the coprescribing of antihypertensive agents.

METHODS

A population-based cohort study was performed using linked administrative databases on all Ontario residents 66 years of age or older who were newly treated for hypertension between July 1, 1994, and March 31, 2002, and did not have diabetes or other relevant comorbidities. All patients were followed for two years to determine which antihypertensives were prescribed concurrently.

RESULTS

Of the 166,018 patients in the described cohort, 1819 (1%) were prescribed a combination therapy tablet as their first-line therapy. The number of patients prescribed antihypertensive polytherapy within the first two years of diagnosis increased from 2071 (21%) of the 9825 hypertensive patients starting treatment in the second half of 1994 to 2578 (37%) of the 6988 hypertensive patients beginning treatment in the first quarter of 2002 (P<0.0001). Overall, 11,003 (27%) of polytherapy prescriptions were for drugs without additive hypotensive effects when combined and this proportion did not change over time.

CONCLUSIONS

Although there has been an increase in the use of polytherapy in elderly hypertensive patients without comorbidities in Ontario over the past decade, more than one-quarter of the two drugs prescribed together have not been proven to have additive hypotensive effects. Because this likely contributes to suboptimal blood pressure control rates, future guidelines and educational programs should devote increased attention to the choice of optimal polytherapy combinations.

Compliance and fixed-dose combination therapy

Despite data on the importance of blood pressure control in preventing cardiovascular and cerebrovascular events, only 34% of hypertensive patients have their blood pressure under control. The National Council on Patient Information and Education has estimated that the compliance rate is just over 30% for chronic conditions like hypertension. Polypharmacy and complex treatment regimens have been identified as important, modifiable risk factors for medication noncompliance. Fixed-dose combination regimens are attractive options because of the improved antihypertensive efficacy resulting from the dual mechanistic action of components targeting different effector mechanisms. One drug in the fixed-dose combination may negate an adverse effect of the other medication. Above all, fixed-dose combination therapy reduces pill burden and improves medication compliance, which can translate into better cardiovascular outcomes. Fixed-dose combinations should be used routinely for the management of hypertension and should also be considered when initiating therapy for patients with newly diagnosed hypertension.