A Prospective, Randomized Open-Label Study for Assessment of Antihypertensive Effect of Telmisartan Versus Cilnidipine Using Ambulatory Blood Pressure Monitoring (START ABPM Study)

BACKGROUND: The antihypertensive agent telmisartan is an angiotensin II receptor blocker with a terminal elimination half-life of 24 h and has a high lipophilicity, thereby enhancing its bioavailability. Another antihypertensive agent, cilnidipine is a calcium antagonist and has dual mode of action on the calcium channels. This study aimed at determining effect of these drugs on ambulatory blood pressure (BP) levels. METHODS: A randomized, open-label, single-center study was conducted during 2021 - 2022 on newly diagnosed adult patients with stage-I hypertension, in a mega city of India. Forty eligible patients were randomized to telmisartan (40 mg) and cilnidipine (10 mg) groups, with once daily dose administered for 56 consecutive days. Ambulatory blood pressure monitoring (ABPM) (24 h) was performed pre- and post-treatment, and the ABPM-derived parameters were compared statistically. RESULTS: Statistically significant mean reductions were observed in all BP endpoints in telmisartan group but only in 24-h systolic blood pressure (SBP), daytime and nighttime SBP, and manual SBP and diastolic blood pressure (DBP) in cilnidipine group. The mean change from baseline to day 56 between two treatment groups showed statistical significance in last 6-h SBP (P = 0.01) and DBP (P = 0.014), and morning SBP (P = 0.019) and DBP (P = 0.028). The percent nocturnal drop within and between groups was statistically nonsignificant. Also, the between group mean SBP and DBP smoothness index differed nonsignificantly. CONCLUSIONS: Telmisartan and cilnidipine once daily were effective and well tolerated in the treatment of newly diagnosed stage-I hypertension. Telmisartan provided sustained 24-h BP control and may offer advantages over cilnidipine in terms of BP reductions, particularly over the 18- to 24-h post-dose period or critical early morning hours.