Calcium Channel Blockers in Veterinary Medicine

Abstract

Calcium channel blockers are becoming increasingly popular in veterinary medicine for the treatment of systemic hypertension, cardiac arrhythmias, and hypertrophic cardiomyopathy. Calcium is vital to many cellular functions and thus stringent regulation of intracellular calcium concentrations is required. Pharmacologic manipulation of the regulatory mechanisms has the potential to alter cellular function in all body systems. In human medicine, calcium channel blockers are being evaluated for, among other things, use in treating glaucoma, deep vein thrombosis, and pulmonary hypertension, in renal transplantation, and for prevention of reperfusion injury. The potentially beneficial effects of these drugs have often been overshadowed by adverse effects including hypotension, inappetence, bradycardia, conduction abnormalities, and decreased cardiac output. With the introduction of sustainedrelease formulations (diltiazem) and 2nd generation calcium channel blockers (amlodipine) many of these effects have been attenuated or eliminated. This paper will review the functions of calcium and the calcium channels as well as discussing the classes and current and potential uses of the various calcium channel blockers.

Occurrence of systemic hypertension in dogs with acute kidney injury and treatment with amlodipine besylate

“…Amlodipine is a dihydropyridine calcium channel blocker (CCB) with direct peripheral vasodilatory effects and weaker central negative chronotropic and inotropic effects (Stopher and others 1988, Cooke and Snyder 1998, Atkins and others 2007). It is considered the treatment of choice for the management of SHT in cats with CKD (Henik and others 1997, Snyder 1998, Maggio and others 2000).…”

Factors Influencing the Relationship Between the Dose of Amlodipine Required for Blood Pressure Control and Change in Blood Pressure in Hypertensive Cats

“…Amlodipine is a second‐generation dihydropyridine and exerts its effects by blocking L‐type calcium channels in vascular smooth muscle. It binds and dissociates from its receptor fairly slowly, which accounts for the gradual onset and slow waning of effect . This, in combination with its long plasma half‐life, means amlodipine only needs to be administered once every 24 hours .…”

Amlodipine effects on vasomotion in rabbit external ophthalmic artery

“…It is a very widely used calcium channel blocker in arterial hypertension therapy. It has a longer elimination half-life than other dihydropyridines (30 hours in the dog), suffering less variation in plasma concentration during chronic administration [1]. In anaesthetized Beagle dogs, it has been demonstrated that amlodipine increased blood flow within the ocular circulation [5].…”

“…Calcium enters excitable cells through different types of voltage-gated calcium channels. Among them, the L-type is the predominant calcium channel in skeletal, cardiac and vascular smooth muscle [1]. Drugs Luís Silva-Carvalho-in memoriam This work was supported by CIISA (Centro de Investigação Interdisciplinar em Sanidade Animal).…”

“…Amlodipine is an L-type calcium channel inhibitor selective for vascular smooth muscle, with little effect on cardiac contractility [1]. It is a very widely used calcium channel blocker in arterial hypertension therapy.…”