Recent guidelines for the therapy of arterial hypertension recommend the use of fixed dose combinations (FDC) of antihypertensive drugs. Due to improved compliance, FDCs are expected to improve blood pressure (BP) control. However, while beneficial effects of FDC on compliance were confirmed, an improvement in BP control could not be demonstrated in a recent meta-analysis. Therefore, the goal of this subanalysis of the Swiss Hypertension Cohort Study (HccH) was to analyze BP control in patients receiving FDCs.Design and method:
Data from HccH were analyzed. From 2005 to 2013 1004 patients were recruited. A follow up of up to six years was performed by 91 general practitioners (GP) in Switzerland. BP control in patients receiving a fixed dose combination of antihypertensive drugs and patients receiving a combination of monotherapies were compared.Results:
44.5% of all patients in our cohort were treated with a FDC, 99% of these received a fixed combination of two agents. In patients receiving combination therapy, 69.5% received a FDC. 79.4% of the prescribed FDC contained an angiotensin receptor blocker plus a thiazide diuretic or an angiotensin converting enzyme inhibitor plus a thiazide diuretic. Patients with FDC received thiazide diuretics much more frequently than patients taking single drug combinations.Results:
BP control was 47.9% in patients receiving free combinations and 61.1% in patients receiving FDCs.Results:
BP control was significantly worse in patients receiving FDC (x2 (1, N = 519) = 7.793, p < 0.005), even after correction for age, gender, BMI and the prescribing GP.Conclusions:
Improved compliance but not necessarily improved BP control has been reported in a recent meta-analysis of trials investigating the effects of FDCs. The results of our study suggest worse BP control in patients receiving FDCs compared with patients receiving free combination, challenging the broad usage of FDC. Differences in BP control may be due to differences in the selection of antihypertensive drugs when prescribing FDCs compared to combinations of single drugs. A further reason may be that dosage escalation is more difficult in patients using FDC, thereby negatively affecting BP control.