Calcium channel blocker
Calcium channel blockers are pharmacological agents that block calcium channels. These drugs are effective for pure diastolic dysfunction, angina, peripheral vascular disease, Raynaud's disease, and black patients. Contraindications include systolic dysfunction, heart block, dyslipidemia and insulin resistance.
Irrespective of structure, all calcium channel blockers block calcium ion entry by blocking the slow inward calcium channel (ISI). However, selectivity towards cardiac vs. vascular tissues varies.
For vasospastic angina, all classes are effective in reducing coronary constriction via a direct dilating influence, and an improvement is generally seen in more than 90% of patients, with a large percentage showing complete elimination of anginal episodes. For stable angina, all are effective by reducing oxygen demand via decreasing afterload, heart rate and contractile force. For unstable angina, treatment is only effective if a vasospastic component can be demonstrated.