Efficacy and tolerability of amlodipine/valsartan combination therapy in hypertensive patients not adequately controlled on amlodipine monotherapy

Objective: This study was designed to explore antihypertensive efficacy and safety of a combination of amlodipine (CCB) and valsartan (ARB), in essential hypertensive patients not adequately controlled by amlodipine monotherapy. Methods: This was a multi-centre, randomised, double-blind, active-controlled study in patients with essential hypertension. After a washout period followed by a single-blind amlodipine 10 mg run-in period, patients with mean sitting diastolic blood pressure (msDBP) >= 90 mmHg and <110 mmHg were randomised to receive amlodipine/valsartan (10/160 mg o.d.) or amlodipine (10 mg o.d.) for 8 weeks. Trial registration number: NCT00171002. Main outcome measures: The primary efficacy variable was change from baseline in msDBP at study endpoint. Secondary efficacy variables were change from baseline in mean sitting systolic blood pressure (msSBP), responder rate (msDBP <90 mmHg or >= 10 mmHg reduction from baseline) and DBP control rate (msDBP <90 mmHg). Results: Of the 1283 patients enrolled in single-blind period, 944 were randomised to receive amlodipine/valsartan 10/160 mg (n = 473) and amlodipine 10 mg (n = 471). Statistically significant greater reductions (p < 0.0001) from baseline in msSBP/msDBP were observed with combination therapy (12.9/11.4 mmHg) compared to monotherapy (10.0/9.3 mmHg). Responder rate was significantly greater (p = 0.0011) with combination therapy (79.0%) compared to monotherapy (70.1%). The percentage of patients with controlled DBP was also significantly (p < 0.0001) higher with combination therapy (77.8%) compared to monotherapy (66.5%). Incidence of peripheral oedema was slightly higher with amlodipine monotherapy (9.4%) compared to combination therapy (7.6%). Conclusion: The combination of amlodipine/valsartan in this 8-week double-blind study provided additional BP control and was well tolerated in patients inadequately controlled with amlodipine monotherapy. Results should be interpreted with the knowledge that study entry criteria may limit application to a wider population.