In this double-blind, randomised, three-way crossover (latin square design), multicentre study, the aim was to compare the efficacy and tolerability of the fixed combination of felodipine and metoprolol with the individual components as monotherapy. A total of 58 patients with supine diastolic blood pressure of 100-115 mmHg were treated with (1) a fixed combination of felodipine plus metoprolol 5/50-10/100 mg (FM), (2) felodipine 5-10 mg (F) or (3) metoprolol 50-100 mg (M), for 12 weeks each. All treatments were extended-release formulations administered once daily and blood pressure was measured 24 h after dosing. Dose titration was performed after 6 weeks if diastolic blood pressure was > 90 mmHg. After 12 weeks of active treatment, the mean supine blood pressures were 153/89, 159/93 and 163/94 mmHg with FM, F and M, respectively. The mean differences in systolic/diastolic blood pressure were -5.6/-3.1 mmHg (p = 0.007/p = 0.002), -10.2/-4.4 mmHg (p < 0.0001/p < 0.0001) and -4.6/-1.4 mmHg (p = 0.03/p = 0.15) for FM vs F, FM vs M, and F vs M, respectively. Blood pressure control (supine diastolic blood pressure < or = 90 mmHg) after 12 weeks was achieved in a significantly greater proportion of patients during treatment with FM than with F or M; 71%, 45% and 40% were controlled with the respective treatments. With FM, 45% of the patients were taking the higher dose after 12 weeks of treatment. The corresponding figures for F and M were 60% and 67%, respectively. Thirteen of the 58 patients (22%) were controlled only with FM.(ABSTRACT TRUNCATED AT 250 WORDS)