Verapamil cardiovascular effects

Diitiazem [dil TYE a zem] has cardiovascular effects that are similar to those of verapamil. It reduces the heart rate, although to a lesser extent than verapamil, and also decreases blood pressure. In addition, diitiazem can relieve coronary artery spasm and is therefore particularly useful in patients with variant angina. The incidence of adverse side effects is low. Figure 18.4 shows treatment of angina in patients with concomitant diseases. 

Alternate treatments. Mood-stabilization and control of manic or hy-pomanic episodes in some subtypes of bipolar illness may also be achieved with the anticonvulsants valproate and carbamazepine, as well as with calcium channel blockers (e.g., verapamil, nifedipine, nimodipine). Effects are delayed and apparently unrelated to the mechanisms responsible for anticonvulsant and cardiovascular actions, respectively. 

The effects of the prototypical calcium channel blockers are seen most prominently in the cardiovascular system (Table 19.1), although calcium channels are widely distributed among excitable cells. The following calcium channel-blocking drugs are clinically the most widely used compounds in this very extensive class of pharmacological agents amlodipine, diltiazem, isradipine, nifedipine, nicardipine, nimodipine, and verapamil. 

CCAs (channel blockers influx inhibitors) have been used primarily for the treatment of cardiovascular disorders (e.g., supraventricular arrhythmias, angina, and hypertension). Agents such as verapamil exert their effects by modulating the influx of Ca across the cell membrane, thus interfering with calcium-dependent functions. Based partly on the common effects of lithium and this class of drugs (e.g., effects on Ca "" activity), the CCAs have been studied as a potential treatment for mania. Janicak et al. (251) reported the results of a 3-week, double-blind comparison of verapamil versus placebo, which did not demonstrate a beneficial effect for verapamil (up to 480 mg/day) in 33 acutely manic hospitalized patients. 

Bestehorn HR Neumann FJ, Buttner HJ, etal. Evaluation ofthe effect of oral verapamil on clinical outcome and angiographic restenosis after percutaneous coronary intervention the randomized, double blind, placebo-controlled, multicenter Verapamil Slow-Release for Prevention of Cardiovascular Events After Angioplasty (VESPA) Trial. J Am Coll Cardiol 2004 43 2160-2165. 

Verapamil (Calan and others) is a calcium channel blocker used for the treatment of cardiac disorders that has also been used off-label as a mood leveler. It can produce a variety of cardiovascular side effects. 

The two stereoisomers of verapamil differ extensively in their pharmacodynamics. The S enantiomer is the more pharmacologically active of the two relative to the cardiovascular system (3,6-9). The cardiovascular pharmacod maniic effects and relative potency of S- and R-verapamil are summarized in Table 1. 

Echizen, H., Manz, M. Eichelbaum, M. (1988) Electrophysiologic effects of dextro and levo verapamil on sinus node and AV function in humans. Journal of Cardiovascular Pharmacology, 12, 543-546. 

Satoh, K., Yanagisawa, T. Taira, N. (1980) Coronary vasodilator and cardiac effects of verapamil in the dog. Journal of Cardiovascular Pharmacology, 2, 309-318. 

Verapamil, proprietaiy name Calan, is a calcium channel blocker that is effective in the treatment of various cardiovascular disorders, including angina (classical and variant), arrhythmias (paroxysmal supraventricular tachycardia), atrial flutter, atrial fibrillation, hypertrophic cardiomyopathy (idiopathic hypertrophic subaortic stenosis), hypertension, congestive heart failure, and Raynaud s phenomenon, along with the preservation of ischemic myocardium and the treatment of migraine headaches. 

Lefrandt JD, Heitmann J, Sevre K, et al. Contrasting effects of verapamil and amlodipine on cardiovascular stress response in hypertension. Br J Clin Pharmacol 2001 52 687-692. 

Verapamil, nifedipine, and diltiazem lower blood pressure with an efficacy comparable to that achieved by other commonly used agents. Their specific effects on the cardiovascular system are as follows ... 

During activation of postganglionic sympathetic nerves there is an exocytotlc release of norepinephrine which is dependent upon the movement of calcium across the neural cell membrane. The effects of CEB on stimulus-secretion coupling in S3nnpathetlc nerves has been studied in several different preparations. Verapamil does not affect the neural release of norepinephrine in either Isolated cat heart or in the pithed rat. In the latter model nifedipine blunted increases in blood pressure due to activation of sympathetic nerves but did not affect cardiovascular responses to exogenous norepinephrine suggesting a prejunctional site of inhibition. 

Verapamil Clinical benefit seen in breast cancer and NSCLC patients, but as a calcium channel blocker to lower blood pressure, frequent hypotension, and other intolerable cardiovascular side effects observed... 

Edouard A Froidevaux R, Berdeaux A, Ahmad R, Samii K, Noviant Y. Bupivacaine accentuates the cardiovascular depressant effects of verapamil in conscious dogs. Eur J Anaesthe-520/(1987) 4, 249-59. 

There is evidence that most NSAIDs can increase blood pressure in patients treated with antihypertensives, although some studies have not found the increase to be clinically relevant. In various small studies, indometacin appeared not to reduce the hypotensive effects of amlodipine, felodipine, nicardipine, nimodipine or verapamil, but it did in one of two studies with nifedipine, and one study with nitrendipine. Similarly, ibuprofen caused a small reduction in the antihypertensive effects of amlodipine. Diclofenac and sulindac appear not to interact with nifedipine, nor ibuprofen, naproxen, piroxicam or sulindac with verapamil, nor naproxen with nicardipine. Low-dose aspirin did not alter the antihypertensive effect of felodipine or nifedipine in one study, and long-term aspirin did not alter the cardiovascular benefits of nitrendipine in another. Diclofenac reduces verapamil serum levels and raises those of isradipine, but these changes are probably unimportant. 

An isolated report describes acute hyperkalaemia and cardiovascular collapse when dantrolene was given to a patient taking verapamil, but not when he was subsequently given nifedipine. Animal studies have found similar effects with the combination of dantrolene and verapamil or diltiazem, but not with nifedipine or amlodipine. 

Lynch C, Drrrbin CG, Fisher NA, Veselis RA, Althaus JS. Effects of dantrolene and verapamil on atrioventricular conduction and cardiovascular performance in dogs Amsth Analg (1986) 65, 252-8.3954091... 

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