Adding an antihypertensive to existing regimens associated with greater BP reduction than maximizing dose, with some caveats in adherence

A retrospective study of older veterans with hypertension found that while adding a medication reduced systolic blood pressure by an extra point, patients who received a dose increase instead of a new drug were more likely to maintain the regimen.

Patients prescribed an additional hypertensive medication had slightly more reduction in systolic blood pressure (SBP), while those who received an increased dose of a current medication better maintained the intensified regimen, a study found.

Researchers studied Veterans Health Administration data for patients ages 65 years or older with hypertension, defined as an SBP of 130 mm Hg or higher, who were taking at least one antihypertensive medication at less than the maximum dose. The retrospective trial compared outcomes in patients who either had new medications added or the dose of an existing medication increased. Results were published Oct. 5 by Annals of Internal Medicine.

Among 178,562 patients, 45,575 (25.5%) added a new medication and 132,987 (74.5%) maximized their doses. Compared with maximizing the dose, adding a new medication was associated with less probability of sustaining the new regimen (50% versus 65%). Both strategies reduced SBP, but when a medication was added, the reduction in mean SBP was 1.1 mm Hg greater over 12 months.

The researchers noted that only 2% of patients were female and that confounding and bias cannot be completely eliminated because of the study's observational design. “When adapting antihypertensive medication regimens, it is important to consider not only [blood pressure] control but also the risk-benefit ratio of each antihypertensive medication in light of all comorbid conditions and comedications and the added complexity of adding an additional medication, particularly in older patients with multiple comorbid conditions, who are more vulnerable to adverse effects of medication and frequently receive multiple medications,” the authors wrote.

An editorial added that the main shortcoming of the study is that treatment intensification differs with number and doses of antihypertensive drugs, number of pills per day, blood pressure level, comorbid conditions, and fitness, especially in older patients. Such a heterogeneous population prevents the study from showing how best to intensify treatment in patients with uncontrolled hypertension, in general or in any given situation, the editorialist said.

“When intensification is indicated, we should not waste time with elaborate reasoning: Either add a drug or maximize the dose of existing drugs, whichever seems to fit best with the patient's current treatment, clinical state, and preferences,” the editorialist wrote. “We must try to keep the treatment as simple as possible but remember that increasing the dose of a single drug has a limited effect on the overall potency of a combination.”