Efficacy and safety of low-dose antihypertensive combination of amlodipine, telmisartan, and chlorthalidone: A randomized, double-blind, parallel, phase II trial

The aim of this clinical trial was to assess the efficacy and safety of low-dose triple combinations of amlodipine, telmisartan, and chlorthalidone in patients with essential hypertension. After a 2-week placebo run-in period, 176 patients were randomized to seven treatment groups (placebo, quarter-dose combination, third-dose combination, half-dose combination, amlodipine 5 mg, amlodipine 10 mg, and telmisartan 80 mg) and administered the assigned study drug orally for 8 weeks. The primary efficacy endpoint was the change in the mean sitting systolic blood pressure (BP) (MSSBP) at Week 8. The MSSBP and mean sitting diastolic BP in the quarter-dose and half-dose groups were significantly lower compared to the placebo and amlodipine 5 mg groups, with similar BP-lowering effects observed compared to the amlodipine 10 mg and telmisartan 80 mg groups. However, the third-dose group showed significant BP improvement only compared to the placebo group. A similar pattern was observed for the control rate of hypertension and response rates. Additional analysis was conducted after correcting for gender and age effects, and, as a result, the third-dose group showed similar results with regard to the BP-lowering effect as the quarter-dose and half-dose groups. In terms of safety, no special adverse events and clinically significant results were noted, and all dose groups of the triple combination are considered safe for use in essential hypertension patients. The current findings indicated that low-dose triple combination of amlodipine, telmisartan, and chlorthalidone over 8 weeks effectively improved the BP-lowering effect in patients with essential hypertension without any safety concerns.