Objectives Hypertension is one of the most prominent risk factors for cardiovascular diseases especially stroke, coronary artery disease and heart failure. Hypertension is often associated with other cardio-metabolic disorders in particular diabetes, obesity and left ventricular hypertrophy (LVH), the latter being found in 70% of diabetic patients.

Hypertensive subjects with co-morbidities frequently require anti-hypertensive combination therapy to achieve satisfactory long-term blood pressure (BP)control. The Perindopril and Amlodipine Fixed Combination (PAFC) has been thoroughly studied internationally but no data is yet available among Thai hypertensive patients.

To evaluate the efficacy and safety of Perindopril and Amlodipine Fixed Combination at 5/5 mg (PAFC 5/5) in untreated or uncontrolled hypertensive patients at hospital hypertension clinics in Thailand.

Methods A prospective, opened lable PAFC regimen was prescribed to untreated or uncontrolled hypertensive patients with systolic and diastolic blood pressure (SBP/DBP) at entry above 140/90 mmHg at ambulatory hypertension clinic. Uncontrolled patients were either switched to or added on with PAFC PAFC’s safety and efficacy was assessed on the first and on the third month after initiating treatment in accordance with Pharmacovigilance safety-monitoring program required by health authority. Standardised BP monitoring device was used to measure blood pressure. The treatment acceptability was evaluated from patient interview. Statistical analysis was based on descriptive statistics and included paired t-test and repeated ANOVA.

Results 302 Thai hypertensive patients were recruited from 15 hypertension clinics. The patients demographics were as follows: gender, 52% male and 48% female, the mean (SD) age was 57. 9(12) years with 91(30%) of patients above 65 years of age, 29(10%) smokers, 38(13%) alcoholic drinkers, 151(50%) having Body Mass Index (BMI) superior or equal to 25 kg/m². Importantly, 213(71%) patients had co-morbidity, the most common one being type 2 DM present in 178(59%) of them. 163(54%) and 127(42%) were at hypertension stage 1 and 2 respectively. 211(69.8%), 70(23.2%) and 21(7.0%) patients were untreated, switched and added-on respectively.

Baseline SBP/DBP(SD) in the overall population was at 158.5(15.7)/94.3(11.3) mmHg. After 3 months treatment with PAFC, BP was reduced to 131(12.5)/79.3(8.7) mmHg (p < 0.001). Likewise, mean arterial pressure (MAP) was reduced from 115.7(10.8) to 96.6(8.5) mmHg (p,0.001) The drop in BP was quite similar between patients with or without co-morbidities: those with type 2 DM had a significant 27.5(1.3) and 14.2(0.9) mmHg drop in SBP and DBP respectively which was the same as those without type 2 DM:27.6(1.5) and 16(0.9) for SBP and DBP drop respectively (p < 0.001). In addition, patients with stage 2 hypertension had a 27.5(1.6) and 13.7(1) mmHg drop in SBP and DBP respectively at one month and 37.9(1.4) and 19.3(1.1) mmHg drop in SBP and DBP respectively at 3 months. There were a few side effects reported during the study, the most common being dizziness (7.3%), cough (6%) and nausea (1%).

Conclusions Perindopril and Amlodipine Fixed Combination 5/5 mg (PAFC 5/5) is an effective and well tolerated antihypertensive agent for Thai hypertensive patients with or without co-morbidities. Its marked reduction in both systolic and diastolic blood pressure in more severe patients or inadequately treated individuals makes this approach particularly suitable within the context of hospital hypertension clinic.