The effect of nifedipine on the pharmacokinetics and dynamics of diltiazem: the preliminary study in normal volunteers

Calcium channel blocker class heterogeneity: select aspects of pharmacokinetics and pharmacodynamics

Calcium channel blockers (CCBs) comprise a heterogeneous group of compounds with unique structures and pharmacologic characteristics. These agents are employed in the treatment of hypertension, coronary ischemia, and/or supraventricular arrhythmias. CCBs are both substrates for, and in the instance of verapamil and diltiazem inhibitors of, cytochrome P450 3A4. In the case of verapamil and diltiazem, this inhibitory effect increases the likelihood of drug-drug interactions with other compounds similarly metabolized by cytochrome P450 3A4. Much of the debate with reference to a cardiovascular risk for CCBs has been quieted with the advent of sustained-release delivery systems that offer a more gradual rate of drug delivery. The most common side effects with CCBs are vasodilatory in nature and include peripheral edema, flushing, and headache. Despite the potential for side effects with CCBs, their potent blood pressure-lowering effect makes them a prerequisite for blood pressure control in many patients.

Current concepts of pharmacotherapy in hypertension: combination calcium channel blocker therapy in the treatment of hypertension

Effective control of blood pressure is usually achieved only with the use of two or more antihypertensive medications. The treatment options for hypertension are numerous, and the number of possible combinations large. The selection of a specific combination drug regimen has often been linked to the perceived need for diuretic therapy as first- or second-step therapy; thus, the popularity of such drug combinations as an angiotensin-converting enzyme (ACE) inhibitor/diuretic, an angiotensin-receptor blocker/diuretic, or a beta blocker/diuretic. Rational alternatives exist, including an ACE inhibitor/calcium channel blocker (CCB) or a dihydropyridine CCB/b blocker combination. Traditionally, recommendations have advised against the use of combination therapy with two drugs from the same therapeutic class. However, because of the different binding and pharmacologic characteristics of CCBs, a rationale exists for combining different agents in this class in the management of hypertension and/or symptomatic coronary artery disease. In the treatment of either hypertension or angina, combination CCB therapy can prove uniquely successful.