. Because of studies showing that t

. Because of studies showing that the rapid, potent, and unpredictable hypotensive effect of native nifedipine increases the risk for angina and myocardial infarction in susceptible individuals, this drug is not recommended for the treatment of hypertensive urgencies or emergencies.36 After oral administration, most of the CCBs undergo extensive first-pass metabolism that contributes to the relative short half-life of verapamil, diltiazem, and nifedipine, and requires they be taken 2 or 3 times daily to maintain 24-hour efficacy.