Dyskalemia risk associated with fixed-dose anti-hypertensive medication combinations

A model-based meta-analysis quantified comparative dyskalemia risk (hyper- or hypo-kalemia) in hypertensive patients treated with angiotensin receptor blockers (ARBs), a calcium channel blocker (CCB) and/or a thiazide diuretic (hydrochlorothiazide; HCTZ) as monotherapy or as fixed-dose combinations. Among 15 randomized controlled trials in a US Food and Drug Administration regulatory review database, dyskalemia events were reported by five trials (24 treatment arms, 11,030 subjects, 8-week median follow up time). The five trials evaluated monotherapy (ARB or HCTZ) alongside dual (ARB + HCTZ, ARB + CCB, or HCTZ + CCB) or triple fixed-dose combinations (ARB + CCB + HCTZ). Hypo- and hyper-kalemia rates were analyzed jointly to account for correlation. Significant drug class, drug, or dose effects were included in the final model. Effect on various drug- and dose combinations on dyskalemia risk were simulated and compared with model-estimated placebo arm dyskalemia risk. After a typical follow-up of 8 weeks, fixed-dose combinations of ARB with a high dose (25 mg) of HCTZ were associated with a higher hypokalemia risk difference (RD) from placebo (e.g.,Valsartan + HCTZ: 2.52%[95%CIs:1.17, 4.38%]). However, when ARB was combined with a lower, 12.5 mg dose of HCTZ, hypokalemia RD from placebo was not significant (Valsartan + HCTZ: -0.03%[-0.80, 0.71%]). ARB monotherapy raised hyperkalemia RD from placebo (1.3%[0.3, 3.6%]). Hyperkalemia risk was not appreciably higher than placebo for any FDC that combined ARB with HCTZ (Valsartan + HCTZ: 0.06%[-1.48, 1.64%]). In uncomplicated hypertensive patients, ARB + 12.5 mg HCTZ fixed-dose combinations are safer with respect to dyskalemia than either ARB or HCTZ monotherapy for initial antihypertensive treatment.