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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The antihypertensive effect of an oral slow release (retard) formulation of verapamil was evaluated in a negative (placebo) and positive (nifedipine) controlled study. After a run-in period of one week without antihypertensive therapy, 54 patients were classified as having mild to moderate hypertension (diastolic blood pressure 95-115 mm Hg) and assigned randomly to one of three groups (n = 18 each). These received one of the following treatments over 2 weeks: either placebo b.i.d., or a nifedipine retard preparation 20 mg b.i.d., or a verapamil retard preparation 240 mg b.i.d. Assessments of blood pressure were made at rest and during a standardized bicycle stress test. Data were recorded at baseline and at the end of each week. After one week of treatment, 1 patient receiving nifedipine and 14 patients receiving placebo dropped out of the study because their diastolic pressures were equal to or above the values before treatment. After two weeks of treatment, 13 of 18 patients on verapamil and 9 of 18 patients on nifedipine had resting diastolic pressures less than or equal to 90 mm Hg. Also systolic pressure and blood pressures during exercise were significantly lowered by both active drugs. Verapamil caused a fall in heart rate during rest and under maximal exercise. Undesired side effects from verapamil were constipation (6 of 18) and headache (1 of 18); those from nifedipine were flush or headache (5 each of 18); ankle edema, dizziness, or tachycardia were each reported by one patient. In comparison with placebo values, verapamil lengthened the atrioventricular conduction time (PQ-interval) significantly, however, PQ-interval did not exceed 0.24 s.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Controlled study on the treatment of hypertension with verapamil in retard form]. 390 62

The acutely hypertensive patient may present with a broad spectrum of dysfunction. Given the wide variety of signs and symptoms, clinical settings, pathophysiological mechanisms, and type of end organ dysfunction, there is no ideal antihypertensive agent. In selecting an agent for treating such patients, the physician must consider efficacy in a variety of settings, rapidity of onset of action, duration of action, and ease of administration. In addition, one should keep in mind the risk of producing hypotension, the contraindication profile, the side-effect profile, and the cost and long-term usefulness of the agent. In this review, the calcium channel blockers verapamil and nifedipine are compared with drugs such as nitroprusside, diazoxide, hydralazine, labetalol, and clonidine. Verapamil, by intravenous administration, has a rapid onset of action, a reasonable duration of effect, a good side-effect profile, and appears to be useful on a long-term basis. Nifedipine, by oral or buccal administration, is useful in a variety of settings and had a rapid onset of action and reasonable duration of effect. In addition, nifedipine rarely causes hypotension, has minimal contraindications, an excellent side-effect profile, reasonable cost, and long-term utility. There is now extensive worldwide experience with verapamil and nifedipine in acute hypertension. They compare favorably with currently used agents.
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PMID:Calcium-channel blockers in acute hypertension. 393 8

High doses of verapamil, diltiazem or nifedipin were administered to three groups of eight patients each, with severely abnormal left-ventricular (LV) function (mean ejection fraction 0.29). Various haemodynamic measurements were made immediately before and 30 minutes after drug administration: LV ejection fraction, ratio of peak systolic pressure to endsystolic volume index, stroke index, pulmonary capillary closing pressure, and maximal diastolic filling rate. None of these were reduced. In fact, ejection fraction rose by a mean of 0.05, stroke index by a mean of 5 ml/m2, while p.c. closing pressure and contractility did not alter significantly. Verapamil and diltiazem reduced the pressure X rate product (an important determinant of oxygen consumption); nifedipine reduced total systemic resistance. It is concluded that verapamil and diltiazem can be used with advantage in cases of unstable angina, if there are severe abnormalities of LV function; they are to be preferred to beta-blockers in this situation. Nifedipin is the calcium antagonist of choice in hypertension and abnormal LV function.
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PMID:[Verapamil, diltiazem or nifedipine in severe left ventricular functional disorder? A comparative study of the immediate hemodynamic effects]. 394 Aug 29

Forty-three patients with mild to moderate hypertension (supine diastolic blood pressure 95 to 115 mm Hg) were entered into a short-term (3 months) study. All received verapamil, 120 mg 3 times a day. After 1 month of treatment on verapamil alone, supine diastolic blood pressure was normalized (less than 95 mm Hg) in 29 patients (67%). These patients continued with verapamil at the same dosage. In 14 nonresponders (supine diastolic blood pressure greater than 95 mm Hg) a combination of althiazide (15 mg/day) and spironolactone (25 mg/day) was added. This resulted in diastolic blood pressure normalization in 9 additional patients. Verapamil induced a slight but moderate decrease in heart rate after 1 month, but no further decrease was observed thereafter. During the trial, 21% of patients reported adverse effects, mostly transient and mild. No patient had to discontinue treatment because of them. Twenty-six patients on verapamil alone were followed for 1 year. Systolic and diastolic blood pressure was adequately controlled in all patients except 1. In 13 the dosage was decreased to 120 mg 2 times a day. There were no significant differences in blood pressure between this group and patients given 120 mg 3 times a day. It is concluded that verapamil is an effective and safe antihypertensive agent in mildly to moderately hypertensive patients. Because a dosage of 120 mg 2 times a day was as effective as 120 mg 3 times a day, the former should be recommended, as it may improve patient compliance.
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PMID:Short- and long-term treatment of mild to moderate hypertension with verapamil. 395 30

The antihypertensive effect of finoptin (verapamil) and corinfar (nifedipin) and their impact on the hemodynamics and the repolarization complex of the ECG were studied in 52 patients with essential hypertension and 48 patients with secondary arterial hypertension. The calcium antagonists were found to effectively decrease the blood pressure by reducing the peripheral resistance. Verapamil may be recommended for the monotherapy of mild and moderate forms of arterial hypertension, whereas corinfar should be used in cases of marked hypertension and at the third stage of therapy. Patients with electrocardiographic signs of myocardial ischemia show the normalization of the ST segment and a decreased depression of T wave under the impact of corinfar.
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PMID:[Treatment of arterial hypertension with calcium antagonists]. 398 59

The main hemodynamic disturbance occurring in patients with essential hypertension is an increase in the total peripheral resistance. In young patients with hypertension, this disturbance is clearly seen during muscular exercise, even though the calculated resistance might be normal during rest. This article reports results of studies on the long-term hemodynamic effects of two calcium channel blockers, verapamil and nifedipine, in patients with mild to moderate hypertension. Twenty-five men, aged 20 to 64 years, with diastolic blood pressures between 100 and 120 mm Hg before treatment were studied at rest and during exercise on ergometer bicycles. Blood pressure was recorded intra-arterially, and cardiac output was measured. After this initial study, 10 patients were treated with verapamil (from 40 to 80 mg, three times daily) and 15 patients with nifedipine (long-acting form, from 40 to 80 mg daily). After one year, the hemodynamic study was repeated. Both drugs induced a reduction in blood pressure and in the total peripheral resistance without any reduction in the cardiac index. Verapamil reduced heart rate, particularly during exercise, but this effect was compensated by an increase in the stroke volume. The hemodynamic profile of these two calcium channel blockers clearly differs from the hemodynamic effects of beta blockers.
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PMID:Hemodynamic effects of calcium channel blockers at rest and during exercise in essential hypertension. 405 Aug 41

Renal plasma flow, glomerular filtration rate plasma angiotensin II, aldosterone and arginine vasopressin, free water clearance, blood pressure and body weight in 11 patients with mild to moderate hypertension were determined at the end of consecutive 6 week periods of administration of placebo and verapamil up to 120 mg t.i.d. Verapamil induced a 10% reduction in diastolic blood pressure. Compared with placebo none of the other parameters measured changed after treatment with verapamil. There was no significant correlation between blood pressure and arginine vasopressin in plasma. It is concluded that verapamil reduced blood pressure by vasodilatation without activation of the counterbalancing mechanisms commonly seen after treatment with vasodilating drugs, i.e. tachycardia, activation of the renin-angiotensin-aldosterone system, water and salt retention, and without affecting renal haemodynamics. AVP does not seem to be involved in blood pressure regulation in mild to moderate essential hypertension.
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PMID:Effect of verapamil on renal plasma flow, glomerular filtration rate and plasma angiotensin II, aldosterone and arginine vasopressin in essential hypertension. 407 25

The relative efficacies of oral verapamil, a calcium-entry blocking drug, and propranolol, a beta-adrenergic blocking drug, were compared in 12 patients who had both stable angina pectoris and mild to moderate systemic hypertension, using a placebo-controlled, double-blind, randomized crossover protocol. Compared with placebo, both propranolol and verapamil decreased the frequency of anginal attacks and the number of nitroglycerin tablets consumed, and increased exercise duration and total work; there were no significant differences in the antianginal effect of the two drugs. Both verapamil and propranolol reduced the supine and standing systolic and diastolic blood pressure measured at rest; compared with propranolol, however, verapamil had greater effects on standing diastolic blood pressure (p less than 0.002). Resting heart rate was reduced from placebo baseline with large doses of both drugs; compared with verapamil, however, propranolol exerted greater effects on resting heart rate and rate-pressure product. Plasma renin activity was increased from placebo baseline with verapamil (p less than 0.05), but was reduced with propranolol (p less than 0.05); no significant change in plasma aldosterone was seen with either drug. Verapamil appears to be a safe and effective treatment alternative to propranolol for relieving anginal symptoms, improving exercise tolerance, and reducing elevated systemic blood pressure in patients with both angina pectoris and mild to moderate systemic hypertension.
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PMID:Comparison of oral propranolol and verapamil for combined systemic hypertension and angina pectoris. A placebo-controlled double-blind randomized crossover trial. 612 46

The calcium antagonist drug, verapamil, was compared in double-blind, double-dummy, crossover studies with two beta-adrenoceptor blocking drugs, pindolol and labetalol. All were equally effective as antihypertensive drugs in patients with mild-to-moderate hypertension. Verapamil caused a fall in blood pressure by reducing total peripheral resistance, as judged by echocardiographic studies, and had no adverse effects on airways resistance in patients with obstructive airways disease. The favorable hemodynamic effects and absence of serious side effects suggest that verapamil may be an important advance in the treatment of hypertension.
Hypertension
PMID:Comparison of beta-adrenoceptor blockers and calcium antagonists in hypertension. 613 71

The role of calcium in the relaxations evoked by methacholine and A23187 in intact rabbit aortic rings was investigated. Methacholine (10(-8) to 10(-6) M) and the calcium ionophore A23187 (10(-8) to 10(-6) M) produced dose-dependent relaxations of rings which had been contracted with the alpha-adrenergic agonist phenylephrine. The ability of a ring to relax in this manner was correlated with the presence of endothelium as judged by transmission and scanning electron microscopy. Purposely disrupting the endothelium led to a loss of the relaxation response. In these rings methacholine caused dose-dependent contractions at concentrations greater than 10(-7) M. Deletion of Ca++ from the incubation medium inhibited maximum methacholine-induced relaxations by 67% and A23187-induced relaxations by 92%. The Ca++-channel blockers verapamil (10 microM) and nifedipine (0.5 microM) inhibited maximum methacholine-induced relaxations by 39% and 45%, respectively. The blockers had no effect on the methacholine ED50 (2.5 x 10(-7) M) for relaxation. Verapamil and nifedipine also inhibited maximum A23187-induced relaxations by 43% and 47% with no effect on the ED50 (6 x 19(-8) M) for relaxation. A structurally dissimilar vasodilator, sodium nitroprusside (10(-7) M), had no effect on the A23187-induced relaxation. These data are consistent with a role of Ca++ in regulating either the production or release of endothelial-derived relaxing factor(s).
Hypertension
PMID:Calcium- and endothelial-mediated vascular smooth muscle relaxation in rabbit aorta. 627 3


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