Postmarketing Study of Efficacy and Safety of Losartan during the Treatment of Patients with Mild and Moderate Hypertension: LOTHAR Study

Introduction Losartan, the angiotensin type 1 receptor blocker (ARB) exercises its main antihypertensive effect by vasodilatation of peripheral arteries. Objective The aim of this study was to evaluate the antihypertensive effect and safety of losartan in patients with mild and moderate arterial hypertension (AH). Methods This was an open post-marketing study with losartan as monotherapy in previously treated or untreated patients with AH. Primary efficacy parameter was the percentage of patients that achieved target blood pressure after 8-week treatment with a single daily dose of losartan of 50-100 mg. Safety parameters were assessed according to the percentage of adverse events and metabolic effects of therapy. Results The study included 550 patients with AH (59% female and 41% male), mean age 56.8 +/- 11.4 years, BMI = 27 +/- 4 kg/m(2). Losartan was applied in 31% of untreated and 69% of previously treatment-resistant patients After 8 weeks target blood pressure was achieved in 67.8% (SBP) and in 81.1% (DBP) of patients, respectively. The mean decrease was 21.8% for SBP and 21.1% for DBP (p<0.001). Out of all, 65% of patients achieved both target SBP and DBP values. Hydrochlorothiazide was added to the therapy in 11.6% of patients. There were no significant differences in drug efficacy between the entire group and subgroups of patients with diabetes mellitus and impaired renal function (p=ns). Adverse events were rare and metabolic effect was favorable. Conclusion Monotherapy with losartan in a dosage of 50-100 mg applied during 8 weeks resulted in achieving target values of blood pressure in 65% of patient with mild and moderate hypertension, also including the patients with diabetes mellitus and impaired renal function. Losartan is a safe and metabolically neutral medication.