Lege Artis Medicinae

[The calcium channel blocker verapamil basic properties, pharmacokinetics, interactions, side effects]

KÉKES Ede1, FARSANG Csaba2

JUNE 30, 1992

Lege Artis Medicinae - 1992;2(01 KLSZ)

[The family of calcium channel blockers is very large and includes its prototype, the monophenylalkylamin drug, verapamil. It is a non-selective vasodilator which exerts a powerful effect equally on myocardium, conducting and nodal tissue of the heart, and both central and peripheral vasculature. Verapamil is almost completely absorbed after oral administration. However, because of extensive first-pass hepatic metabolism, only about 20% of the drug is bioavailable. The elimination phase is slow with a half-time varying from 5 to 7 hours. Orally administered verapamil is extremely well tolerated drug with a very low incidence of gastric intolerance, constipation, vertigo, facial flushing headache and pruritus. During intravenous administration the most common side effects are hypotension and and occasional AV conduction disturbances, or bradycardia. Main contraindications are listed. Coadministration of beta receptor blokers, digitalis and disopyramid should be avoided. ]

AFFILIATIONS

  1. Orvostovábbképző Egyetem II. Belklinika
  2. Fővárosi Szent Imre Kórház I. Belgyógyászati Osztály

COMMENTS

0 comments

Further articles in this publication

Lege Artis Medicinae

[Effects of verapamil on cardiac arrhythmias]

ZÁMOLYI Károly

[Verapamil, a „first generation" calcium anta gonist and synthetic papaverine derivate, was initially introduced as a potent peripheral and coronary vasodilator. It was later found to have significant antiarrhythmic activity, the mechanism of which was related to selective inhibition of transmembrane fluxes of the calcium. The electrical activity of the sinus node and of the atrioventricular (AV) node depends primarily on slow inward Ca2+ currents, therefore it is logical to expect that calcium antagonists will be effective here. The main electrophysiologic effects of verapamil include the slowing of conduction and the prolongation of refractoriness in the atrio ventricular node without significantly affecting intraatrial or intraventricular conduction. Thus, verapamil has been effective in the acute termination of reentry tachycardia in volving the atrioventricular node and in slowing the ventricular response during atrial fibrillation or flattern. Since verapamil has little, if any, effect on the electrical activity of the ventricle or the His Purkinje system, it does not provide effective therapy for controlling ventricular tachycardias. This paper focuses on a detailed discussion of the various arrhythmias that respond to calcium antagonist therapy. ]

Lege Artis Medicinae

[Antianginal effects of verapamil]

KÉKES Ede

[Verapamil is the prototype of the calcium antagonists. Administration of the drug produces a beneficial antianginal effect due to de creased preload and afterload through vasodilation without marked reflex tachycardia and also due to a special influence on myocardium (negative inotropy and positive lusitropy) in all forms of ischaemic heart disease. Verapamil is also a strong coronary dilator drug. Verapamil was given in doses of 240–360 mg daily. The investigators concluded that exercise tolerance increased and the number of anginal attacks and nitroglycerin (sublingual) consumption decreased. The rate-pressure product is reduced on verapamil. Its cardio protective effect on myocardial structure is still an object of discussion.]

Lege Artis Medicinae

[Verapamil treatment in hypertrophic cardiomyopathy]

DÉKÁNY Miklós

[The main aims of therapy in hypertrophic cardiomyopathy, in which ways the symptoms of the patients can be decreased and their survival can be made longer, are as follows: to ameliorate the impaired ventricular relaxation during diastole, to decrease or abolish the obstruction to the left ventricular outflow in systole, as well as to prevent or abolish the atrial and ventricular arrhythmias. Verapamil treatment can be advantageous in each of the above respect. The author describes the characteristics and pathophysiology of the disease in order to understand the favourable effects of Verapamil. On the basis of the literature he gives an outline of the experiences attaining with the application of the drug. He makes the reader acquainted with the results of follow-up studies and with his own observations treating 35 patients with verapamil.]

Lege Artis Medicinae

[Application intravenous verapamil in hypertonic crises]

NAGY Viktor, ISKUM Miklós

[Hypertensive crisis becomes manifest in two clinically well distinguishable forms. Life threatening cases require immediate intervention, while in cases not immediately life threatening, the situation is less critical, but a delay in treatment may lead to serious organ damage. The authors administered 5 mg verapamil intravenously during 3 minutes to 46 patients (mean age 65,7 years, 31 women, and 15 men). The initial blood pressure of 226/125 mmHg decreased to 193/97 mmHg, and the heart rate decreased from 98/min to 81/min three minutes following the injection (p < 0,01 at both parameters). No significant change was observed in either the blood pressure or the heart rate during the subsequent 30 minutes. As a side-effect, flushing was observed in two cases. Based on the literature and their own experiences, the authors recommend intravenous verapamil as the drug of choice for life-threatening hypertensive crises associated with angina pectoris and cerebrovascular circulatory disorder in cases where EKG is available. ]

Lege Artis Medicinae

[Verapamil treatment in hypertension]

FARSANG Csaba

[The author describes the mechanisms of action of verapamil, the first calcium antagonist, and also shortly summarizes its indications and ways of administration in hypertension. Its role in antihypertensive combinations and interactions are also conscisely dealt with.]

All articles in the issue

Related contents

Lege Artis Medicinae

[Notes on the management of hypertension in chronic kidney disease ]

AMBRUS Csaba

[The prevalence of hypertension among pa­tients with chronic kidney disease is high, reaching more than 80%. Hypertension is both one of the main causes and also the most common consequence of chronic kidney disease. It is also a main factor responsible for the high cardiovascular morbidity and mortality in this patient population. Blood pressure control can improve patient outcomes, lower cardiovascular risk and slow down the progression of kidney dis­ease, irrespective of the underlying cause. The optimal therapy should therefore focus not only on blood pressure reduction but also on renoprotection. Basic understanding of the renal pathophysiology in hypertension and renal effects of various medications is of paramount importance. In this review, we summarized cornerstones of the antihypertensive therapy in patients with chronic kidney disease. The management of patients receiving kidney replacement therapies, such as hemodialysis, peritoneal dialysis or transplanta­tion requires special knowledge and expe­rience, therefore it is not discussed here. The aim of this review was to allow non-nephrologist physicians to take care of their kidney patients with more confidence and effectiveness.]

Clinical Neuroscience

[Burning sensation in oral cavity - burning mouth syndrome in everyday medical practice]

GERLINGER Imre

[Burning mouth syndrome (BMS) refers to chronic orofacial pain, unaccompanied by mucosal lesions or other evident clinical signs. It is observed principally in middle-aged patients and postmenopausal women. BMS is characterized by an intense burning or stinging sensation, preferably on the tongue or in other areas of the oral mucosa. It can be accompanied by other sensory disorders such as dry mouth or taste alterations. Probably of multifactorial origin, and often idiopathic, with a still unknown etiopathogenesis in which local, systemic and psychological factors are implicated. Currently there is no consensus on the diagnosis and classification of BMS. This study reviews the literature on this syndrome, with special reference to the etiological factors that may be involved and the clinical aspects they present. The diagnostic criteria that should be followed and the therapeutic management are discussed with reference to the most recent studies.]

Lege Artis Medicinae

[Dangers of the use of performance enhancement drugs and food supplements]

PUCSOK József

[The history of humankind is full of stories related to performance enhancement drug abuse. For the purpose of improving explosive power and long-term physical performance central nervous system stimulating drugs and supplements, such as: amphetamine and cocaine have been used. Androgenic anabolic steroids are used for increasing skeletal muscle mass. The abuse of performance enhancer drugs is seriously deteriorating the human health, and have several negative side effects. Number of food-supplements - available in the market, often contain traces of steroids. So called designer steroids are extremely dangerous. In the near future it will be possible to enhance physical performance through genetic interventions.]

Lege Artis Medicinae

[Juvenile idiopathic arthritis: from diagnosis to treatment]

MOSDÓSI Bernadett

[Juvenile idiopathic arthritis is a heterogeneous group of diseases that is one of the most common chronic diseases of childhood. It begins before 16 years of age, the etiology is unknown, it is persisting for at least 6 weeks and other pathologic conditions could be excluded. Juvenile idiopathic arthritis includes several diseases categories, each of them have distinct methods of presentation, clinical symptoms, pathogenesis and treatment options. Recent advances in the understanding of the immunological pathogenesis of the diseases have led to dramatic improvements in treatment. Although the management is using a multidisciplinary approach, the disease often persist into adulthood and can cause significant long-term morbidity and physical disability. Our article discusses the classification, clinical manifestations, differential diagnosis, treatment and complications of juvenile idiopathic arthritis. ]

Lege Artis Medicinae

[THE USE OF GENERIC DRUGS IN THE MEDICAL THERAPY OF EPILEPSY]

RAJNA Péter

[The author demonstrates the relationship between the innovative and generic antiepileptic drugs regarding the clinical aspects. Among the requirements for the registration of generics one can find small differences in the prescribed and the practical levels of bioequivalence. An important but not widely known fact is that these differences can lead to clinically important alterations if the effects of different generics or the effects on high risk patients are compared. While the increasing market of generics is due to economical factors (and rarely due to medical decisions), the safety of the drugs becomes extremely important. From this aspect, special patient populations eg. children, elderly people or patients with multiple illnesses under multidrug treatment are necessarily of greater medical importance. The characteristics of the antiepileptic drugs on the elderly patients, their increased sensitivity to particular adverse events and the possible somatic side effects are discussed in details. The type of epilepsy also has its special characteristics and is important in the choice of the most successful medicine. The development of the antiepileptic drugs shows a positive direction for their efficacy. In the discussion the author points out three main ways for using generic drugs: prescription of generic drug in monotherapy or as an additive in newly diagnosed patients, the exchange of the innovative agent to a generic and the exchange of one generic to another. The author also mentions the legal points and criticizies the regulations available in some countries allowing a free exchange of the bioequivalent drugs without the agreement of the physician or the patient. The final part of the paper reviews the results of the comparative studies on the effects of the generic antiepileptic drugs and the experiences of the physicians of their application based on surveys performed with questionnaires. The data of the literature is compared to the Hungarian methods of application and to his own experience. Recommendations for the application of generic antiepileptic drugs are summarized in „twelve points“.]