['The present study was undertaken to evaluate the efficacy and safety of amlodipine for hypertension treatment in comparison with nifedipine retard.', "We examined 31 patients with arterial blood pressure approximately 155-165 mmHg/100-105 mm Hg at the beginning of the trial. It was a randomized double-blind, parallel-group trial including two groups of patients. Patients of the first group were given active amlodipine and nifedipine retard placebo during 6 weeks, while the second group was given active nifedipine retard and amlodipine placebo. Statistical analysis was made using the paired Student's t-test, chi-square test and ANOVA test.", 'At end point we observed significant decrease in arterial blood pressure after treatment of both drugs. The treatment with nifedipine retard increased the mean heart rate of patients. Amlodipine therapy in comparison to nifedipine retard did not change the heart rate in treated patients. Safety parameters: SGOT, SGTP, creatinine and others were in laboratory norms ranges.'] Do antihypertensive effect of amlodipine compared with nifedipine retard in patients with mild and moderate essential hypertension?