Background: The standard of hypertension control in the population is not satisfactory, only 20 % patients with hypertension achieve target values of blood pressure (BP). Extensive prospective studies revealed that diuretics, beta-blockers as well as the majority of calcium channel blockers and ACE inhibitors can significantly reduce the incidence of complications of hypertension and are therefore considered drugs of first choice in the treatment of hypertension. The additive effects of ACE inhibitors are manifested in particular after larger doses. Objective of trial: To assess the effectiveness and tolerance of the modern long-acting ACE inhibitor - fosinopril - in the treatment of mild and medium severe hypertension and its effect on some anthropometric and laboratory parameters. Results: Fosinopril as monotherapy in amounts of 10, 20 and 40 mg led to normalization of BP in 85 % of the group (n = 203) and was very well tolerated. Only 11 % of the group needed a combina- tion with hydrochlorothiazide - 12.5 g/day - after which normal BP levels were attained. Only 4 % of the patients did not complete the study on account of undesirable effects, incl. 3 patients where cough was the reason for discontinuation. After 12 weeks treatment the systolic BP was reduced on average by 31 mm Hg and the diastolic BP by 16 mm Hg. The heart rate (HR) declined on average by 3 beats/min. (p 0.001). After four weeks treatment a significant decline of the blood sugar level occurred which was even more marked after 12 weeks of treatment (on average by 0.27 mmol/l and at the same time a significant drop of sodium occurred (by 2 mmol/l), of total and LDL-cholesterol (by 0.26 and 0.23 mmol/l). An expected increase of the potassium level occurred (by 0.1 mmol/l) and creatinine (by 3.4
mol/l in plasma). Conclusion: Fosinopril treatment with 10 - 40 mg/day was effective in monotherapy of hypertension in 85 % patients and was well tolerated. After 12 weeks treatment a significant decline of the BP, HR occurred as well as the expected decline of the plasma Na/K ratio and improvement of some metabolic parameters.

        Key words: Treatment of arterial hypertension - ACE inhibitors - Metabolic factors