Abstract

HALLMARKS OF CALCIUM CHANNEL BLOCKERS: A REVIEW

Afshan Siddiq, Iqra Mukhtar and Sadia Ghousia Baig*

ABSTRACT

Calcium channel blockers (CCBs) were unveiled during screening of coronary artery dilators. They work as inhibitors of calcium ions influx through ion specific channels leading to smooth muscle relaxation and ultimately vasodilation. This inhibitory effect also accounts for contractility reduction in the myocardium. They are predominantly discriminated into two classes named as Dihydropyridines (DHPs) and Non-dihydropyridines (NDHPs). DHPs selectively work in vasculature and clinically useful as antihypertensives. They have also found application in stable and vasospastic angina. While NDHPs are more negatively ionotropic and chronotropic and this feature makes them useful in arrythmias management. As 2nd or 3rd line agents, calcium channel blockers are suggested to hypertensive diabetic patients. Nifedipine (a dihydropyridine calcium channel blocker) is now recommended safe for post-operative hypertension management in children of all age groups. Anginal patients unresponsive to β-blocker therapy or contraindicated to it, are successfully managed by calcium channel blockers. CCBs have also been found effective for the prevention of recurrence of myocardial infarction. Evidences exist supporting their efficacy in Raynaud’s phenomena, Glaucoma, and in the management of preterm labor. Besides that, these agents have also been found safer in 1st trimester of pregnancy. Novel additions in calcium channel blockers with tendencies to block channels other than L-type have provided a new insight for future research, as they confer additional properties of cardioprotection, neuroprotection and renoprotection.

Keywords: Calcium Channel Blockers; Dihydropyridines; Non- dihydropyridines; Hypertension.