Triamterene-hydrochlorothiazide combination lowers BP

When added to hydrochlorothiazide, triamterene, a potassium-sparing diuretic, further enhanced the BP-lowering effect of the treatment, according to data published in the Journal of General Internal Medicine.

Researchers studied 17,291 patients with hypertension using data from the Indiana Network for Patient Care database (2004-2012).

Wanzhu Tu

“This study is a perfect example of how we can learn about the previously unknown therapeutic effects of drugs from big data,” Wanzhu Tu, PhD, an investigator at Regenstrief Institute in Indianapolis, scientist at the Indiana University Center for Aging Research and professor of biostatistics at the Indiana University School of Medicine, said in a press release. “In this case, big electronic medical record data are being used to answer questions that may otherwise be unanswerable. It is unlikely that a large clinical trial would be conducted to reexamine the [BP] effect of triamterene, a drug that has been on the market since 1965. Yet smaller clinical trials simply do not provide sufficient power to determine the drug’s effect. Observational studies based on big data, like ours, provide a viable alternative.”

Tu and colleagues used propensity scores to compare BP results among patients taking hydrochlorothiazide with or without triamterene, alone or with other antihypertensive medications. They estimated the propensity score for each medication combination, and stratified patients within each subclass by whether they were taking hydrochlorothiazide with or without triamterene. According to the researchers, this enabled the assessment of the effect of triamterene by combining BP differences from the different subclasses.

Compared with patients taking hydrochlorothiazide without triamterene, those who received combination therapy had a lower mean systolic BP by 3.8 mm Hg (135.75 mm Hg vs. 131.32 mm Hg; P < .0001). The effect on systolic BP of hydrochlorothiazide plus triamterene vs. hydrochlorothiazide without triamterene was similar regardless of the use of other medications, the researchers wrote.

There was no significant difference in diastolic BP between the groups.

“When considered in population-scale proportions, such an effect on BP would be expected to produce a substantial reduction in [CV] morbidity, as well as the benefits derived from less frequent hypokalemia,” Tu and colleagues concluded. “The findings of the present study would appear to generate an additional rationale for considering the inclusion of triamterene in the treatment of hypertension.” – by Erik Swain

Source: www.healio.com