Myocardial con- tractile depression also is a common feature, although the degree is variable according to drug class. As a result of these pharmacological properties, the calcium channel blockers are effective anti-ischemic drugs, but their use must be All classes of calcium channel blockers reduce anginal episodes, increase exercise duration, and reduce use of sublingual nitroglycerin in patients with effort-induced an- gina.854 856 Because all 3 classes also reduce the frequency of Prinzmetal s variant angina, they are the drugs of choice, along with nitrates, used alone or in combination.857 859 Because the 3 classes seem to be equally efficacious in treating angina, the choice of a particular agent should be based on potential drug interactions and adverse events. The dihydropyridine class is preferred over other calcium channel blockers in patients with cardiac conduction defects such as sick sinus syndrome, sinus bradycardia, or significant AV conduction disturbances. Dihydropyridines should be used with caution in patients with severe aortic valve stenosis. Short-acting dihydropyridines in patients with fixed lesions can exacerbate angina, possibly by excessive lowering of arterial pressure with reflex tachycardia, and therefore should be avoided. Short-acting nifedipine seems to increase mortal- ity in patients with hypertension,860 but there is currently no evidence that these concerns apply to extended-release prep- arations.861,862 Because of their effects on contractility, none of the calcium channel blockers are recommended for routine treatment of patients with current or prior symptoms of heart failure and a reduced LVEF.21 Many drug interactions associated with calcium channel blockers occur because of rapid absorption or low bioavail- ability due to high first-pass metabolism by the cytochrome P450 (ie, CYP3A4) system. These pharmacokinetic properties result in high intraindividual and interindividual variability, necessitating dosage adjustment. 