The pharmacologic treatment of hypertension (HT) has been extensively studied by clinical trials. These studies have provided definitive evidence of treatment benefit and the weight and consistency of the clinical evidence has lead to uniformity in many aspects of treatment recommendations worldwide. The international guidelines and current clinical and biostatistical practices were reviewed for relevant clinical, design, end-point assessments and regulatory issues. The results are grouped mainly into ethical, protocol and assessment issues. Ethical issues arise as placebo-controlled trials (PCTs) for HT-lowering agents in patients with moderate to severe HT are undertaken. Patients with organ damage due to HT should not be included in long-term PCT. Active-control trials, however, are suitable for all randomized subsets of patients, including men and women, and different ethnic and age groups. Severity subgroups must be studied separately with consideration to specific study design. Safety studies must be very vigilant on hypotension, orthostatic hypotension and effects on heart. In dose-response studies, at least three doses in addition to placebo should be used to well characterize the benefits and side-effects. Mortality and morbidity outcome studies are not required in anti-HT trials except when significant mortality and cardiovascular morbidity are suspected. Generally, changes in both systolic and diastolic blood pressures (BP) at the end of the dosing interval from the baseline are compared between the active and the control arms as the primary endpoint of anti-HT effect.
The world wide increment of hypertension (HT) and cardiovascular diseases (CVD) is becoming heavier than ever before with each passing year. It is estimated that by 2025, up to 1.58 billion adults worldwide will suffer from some complications of or from HT.  that makes one out of each three adults, on an average, will develop clinical HT or its co-morbidities or both. Currently, the prevalence of HT varies around the world, with the lowest prevalence in rural India (3.4% in men and 6.8% in women) and the highest prevalence in Poland (68.9% in men and 72.5% in women). However, in fact, the low-prevalence rates, e.g. as those cited for India, do not necessarily mean a really low occurrence of the disease in this population. Even in those who are diagnosed with HT, treatment is frequently inadequate. In any case, regardless of the prevalence rate, large or small, HT and related diseases must be intervened for prevention, diagnosis and control.There are numerous trials in hypertension many of which have focused on cardiovascular(CV) outcomes (death, non