A novel particulate guanylyl cyclase receptor B/cGMP activator with selective vasodilating actions in experimental hypertension

Abstract

Purpose: This is a retrospective hypertension (HTN) cohort analysis evaluating initial antihypertensive prescribing of hydrochlorothiazide (HCTZ) or chlorthalidone (CHL) monotherapy and change in initial blood pressure (BP) and electrolytes in a large safety-net institution. Methods: Patients were identified through the Denver Health HTN registry which includes adult patients with at least 1 primary care visit in past 18 months and at least 2 diagnoses of HTN in past 5 years. All patients from the registry were then cross referenced to their medication lists based on prescribing in the medical record. 861 patients were identified as being prescribed HCTZ monotherapy and 75 patients prescribed CHL monotherapy without previous prescriptions of any other antihypertensive therapy. Patient demographics, BP (1st prior to prescription and 1st within 3 months post prescription), serum potassium (1st prior to prescription and 1st within 6 months post prescription), and antihypertensive therapy prescribed were collected. Results: 100 HTN patients with a mean age of 57 were analyzed (50 HCTZ and 50 CHL). The mean lowering of systolic BP (SBP) from baseline was 16.7 12.4 and 23.0 13.4 mm Hg for HCTZ and CHL, respectively (p<0.001). The mean lowering of diastolic BP (DBP) from baseline was 9.1 9.3 and 12.5 10.1 mm Hg for HCTZ and CHL, respectively (p 1⁄4 0.511). Overall, post prescription BP control rate (< 140/90 mm Hg) was 62% and with no significant difference between groups (p 1⁄4 0.837). The mean lowering of serum potassium (K) from baseline was 0.48 1.10 and 0.22 0.56 mEq/L for HCTZ and CHL, respectively (p1⁄4 0.287). Hypokalemia (K < 3.5 mEq/L) occurred in 18.2% and 42.9% of HCTZ and CHL, respectively (p 1⁄4 0.076) with only 50% of patients getting a post prescription K within 6 months. Conclusions: This analysis illustrates a statistically significant reduction in SBP, and no difference in DBP, with use of CHL compared to HCTZ. BP goal attainment was no different between groups. There was a trend towards higher hypokalemia incidence in the CHL vs HCTZ patients, but only 50% of patients had a K checked within 6 months of initial prescribing. This study supports CHL is a more potent diuretic than HCTZ at lowering SBP and that there is a need for greater K monitoring in patients prescribed diuretic monotherapy.