This multicentre hospital study compared the antihypertensive efficacy and the tolerability of once daily felodipine extended release (ER) with twice daily nifedipine retard (R) in hypertensive patients inadequately controlled on metoprolol monotherapy. 2. One hundred patients, aged 20-70 years, whose seated diastolic blood pressure was 100-115 mmHg after 4 to 6 weeks of metoprolol (200 mg day-1) monotherapy, were randomised, double-blind, to receive felodipine ER 10 mg once daily or nifedipine R 20 mg twice daily for 8 weeks. The dosage of felodipine or nifedipine was doubled if seated diastolic blood pressure exceeded 95 mmHg, 2 or 4 weeks after randomisation. Metoprolol 200 mg once daily was taken throughout the trial. 3. Fifty-one patients received felodipine ER and 49 nifedipine R; 46 and 45 respectively completed the 8 week trial. About half of patients on each treatment needed the higher dose. The baseline characteristics of the felodipine and nifedipine groups were generally well balanced. 4. Seated diastolic blood pressure was reduced by 17 mmHg for felodipine (24 h post-dose) and by 9 mmHg for nifedipine (12 h post-dose), a difference between treatments of 8 mmHg (95% confidence interval 5 to 12 mmHg, P less than 0.0001). The attained blood pressures at the end of the study (felodipine 90 +/- 10, mmHg, mean +/- s.d.; nifedipine 95 +/- 10) were also significantly different (95% confidence interval for the 5 mmHg difference, -9 to -1 mmHg, P less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)
