Abstract :
Plasma drug concentration and hemodynamic responses to dihydropyridines correlate closely. Differences in pharmacokinetic profile lead therefore to marked differences in blood pressure (BP) control over 24 h and sympathetic tone and side effects, and also appear to determine effects on left ventricular hypertrophy (LVH) and outcome in patients with coronary artery disease (CAD). Fast-absorbed and short-acting agents (eg, nifedipine capsules) cause intermittent control of BP with rapid decreases in BP after each dose. This rapid fall in BP causes, after each dose, an increase in sympathetic activity, which over subsequent hours gradually disappears. In contrast, long-acting formulations, such as nifedipine gastrointestinal therapeutic system (GITS), or agents with a long elimination half-life, such as amlodipine, provide, during long-term treatment, stable hemodynamic and BP effects with little or no activation of the sympathetic nervous system. Intermittent hemodynamic responses and the resulting sympathetic hyperactivity with the rapid-acting agents are possible explanations for outcome of treatment as it relates to regression of LVH and cardiac events in patients with CAD.
