Differences between calcium antagonists: duration of action and trough to peak ratio

UNLABELLED: Comparison of first- and second-generation calcium antagonists: Despite their diversity of structure, the first-generation calcium antagonists nifedipine, verapamil and diltiazem all have a short elimination half-life and a relatively short duration of action. In contrast, there appears to be wide diversity in these properties among the newer calcium antagonists, which are mostly dihydropyridines. The longer half-life and physicochemical properties of some of the newer agents allow full 24-h blood pressure control. Duration of action of lacidipine: Taken only once a day, lacidipine has proved as potent an antihypertensive agent as slow-release nifedipine administered twice a day. Lacidipine produces a satisfactory fall in blood pressure not only during waking hours but also during sleep at night, as shown by 24-h ambulatory monitoring. Moreover, this blood pressure fall is obtained without any reflex tachycardia or associated side effects. Compared with patients treated with placebo, systolic and mean arterial blood pressure variability (standard deviation) is reduced by lacidipine treatment. CONCLUSIONS: Control of blood pressure using lacidipine once a day meets the criteria proposed by the United States Food and Drugs Administration for antihypertensive drug efficacy and duration of action.