Evaluation of a long acting formulation of nicardipine in hypertension by clinic and home recorded blood pressures and Doppler aortovelography.

1. A novel formulation of nicardipine (50% standard (short acting), 50% sustained release) was evaluated in mild hypertension in a double-blind, randomized, placebo-controlled study, using clinic measurements (Hawksley) augmented by home recorded blood pressures (Copal UA 251). 2. Nicardipine 60 mg twice daily for 28 days produced a highly significant reduction in sitting blood pressure compared with placebo both pre dose (mean difference 17/8 mm Hg) and 2 h post dose (mean difference 34/26 mm Hg). 3. Home recordings confirmed the hypotensive effect and also revealed a consistent 'peak' effect between 2-4 h after dosing (mean difference 32/22) mm Hg). 4. Doppler aortovelography at 2 h post-dose showed a significant increase in in stroke and minute distance (linear analogues of stroke volume and cardiac output respectively) compared with placebo. The increase in stroke distance was linearly related to change in plasma concentration of nicardipine. 5. Of the 14 patients enrolled in the study, nine experienced troublesome adverse effects on nicardipine (headaches, facial flushing, palpitations, ankle oedema) and two of these were unable to complete the study as a result. 6. This formulation of nicardipine, in the fixed dosage used in this study, is characterized by an effective antihypertensive action but also by an unacceptable adverse effect profile, presumably due to an excess of its 'short acting' component.