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Query: UMLS:C0085580 (essential hypertension)
 14,686 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The antihypertensive effect of a new sustained-release matrix formulation of verapamil 200 mg was investigated in a dose-response study in patients with mild to moderate essential hypertension. Noninvasive ambulatory blood pressure measurements were recorded over 24 h in 6 patients with diastolic blood pressure greater than or equal to 100 mmHg. The patients received sustained-release verapamil 200 mg once daily and twice daily in a randomized order. Each medication period lasted 2 weeks. Verapamil 200 mg twice daily had a better antihypertensive effect than the same dose once daily. After a 6-week placebo period 27 patients with a diastolic blood pressure greater than or equal to 100 mmHg were included in a double-blind clinical trial. The patients received sustained release verapamil 200 mg once daily and twice daily in a randomized crossover manner. Each medication period lasted 6 weeks, with an intervening 6-week placebo period. A diastolic blood pressure of less than or equal to 95 mmHg was achieved in 6 patients with the once-daily regimen and in 14 with the twice-daily regimen. The mean fall in diastolic blood pressure was 4 and 9 mmHg, respectively (p less than 0.05). We conclude that sustained-release verapamil 200 mg once daily gives a satisfactory blood pressure response only in a minority of patients, while 200 mg twice daily has a significantly better antihypertensive effect. Both doses were well tolerated.
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PMID:Sustained release verapamil in hypertension. Results from a noninvasive ambulatory blood pressure monitoring and a clinical study. 353 23

In a single-blind, placebo-controlled crossover study the effects of verapamil (450 +/- 30 mg/day) and propranolol (160 +/- 20 mg/day) on endurance time during submaximal exercise were compared in eight patients with essential hypertension. The drugs were given in randomized order. Each active drug period was preceded by a placebo phase. Endurance tests were performed during both placebo periods and treatment with verapamil and propranolol by bicycle ergometry. Both drugs were equally effective in decreasing resting blood pressure. Verapamil and propranolol reduced exercise heart rate, the effect of propranolol being more pronounced. With placebo, endurance time during exercise was 57 +/- 11 minutes; with propranolol it was 32 +/- 7 minutes (P less than 0.05). Verapamil had no influence on endurance time. The study demonstrates that in contrast to propranolol, verapamil has no influence on exercise tolerance during submaximal work in patients with hypertension.
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PMID:The effects of verapamil and propranolol on exercise tolerance in hypertensive patients. 355 58

The effects of graded doses of verapamil were compared with those of a combination of atenolol and hydralazine in a double-blind, randomised, crossover trial in 16 patients with essential hypertension. During the placebo phase, mean arterial pressure (M.A.P.) was 123 +/- 17 mmHg. Verapamil (dose range 160-480 mg/day) lowered M.A.P. to 109 +/- 7 mmHg (p less than 0.01 vs placebo). The combination of atenolol (50-100 mg/day) and hydralazine (50-200 mg/day) lowered M.A.P. to 100 +/- 11 mmHg (p less than 0.001 vs placebo, p less than 0.05 vs verapamil). Neither regimen produced any deleterious effects on electrocardiographic intervals, echocardiographic indices of left ventricular function or plasma lipids. Verapamil was well tolerated and provided satisfactory alternative therapy in these patients with mild-to-moderate essential hypertension.
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PMID:Verapamil in essential hypertension: a comparison with atenolol plus hydralazine. 362 35

Recent studies have suggested a role for adrenaline in the pathogenesis of essential hypertension. In the present study, the effects of several anti-hypertensive agents were compared in normal (plasma adrenaline concentration: 0.267 + 0.040 ng/ml) and adrenomedullectomised (plasma adrenaline concentration: 0.063 + 0.011 ng/ml; p less than 0.01) dogs. The hypotensive and tachycardic effects of phentolamine (1.5 mg/kg i.v.) or dihydralazine (1 mg/kg i.v.) were the same in the two groups of dogs. Verapamil (0.2 mg/kg i.v.)-induced hypotension was less pronounced in dogs without adrenal medulla. In these adrenomedullectomised dogs, clonidine (10 micrograms/kg i.v. or 1 microgram/kg i.c.) elicited tachycardia and its hypotensive properties were delayed. In dogs with neurogenic hypertension, the antihypertensive properties of propranolol (1 mg/kg i.v.) remained unchanged. These results show the importance of adrenal medulla in the antihypertensive action of clonidine, or verapamil. These agents (but not dihydralazine, propranolol or phentolamine) could reduce adrenaline secretion from the adrenal medulla.
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PMID:[Role of the adrenal medulla in the effect of antihypertensive drugs]. 393 35

Sodium efflux rate constants and intracellular sodium were measured in leucocytes from healthy volunteers in the presence and absence of the calcium antagonist verapamil hydrochloride. Verapamil stimulated sodium pump activity and this effect was dependent on the presence of external calcium. Verapamil has been reported to reverse the abnormality of sodium transport seen in leucocytes from patients with essential hypertension and the present study demonstrates that sodium pump activity in leucocytes from control subjects is also stimulated by exposure to verapamil in vitro. This direct cellular effect appears to be due to the calcium antagonist properties of the drug.
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PMID:Effect of the calcium antagonist verapamil on human leucocyte sodium transport in vitro. 396 68

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 question of whether the hypotensive effect of calcium entry blockers involves an interaction with alpha-adrenergic receptors was examined. The effect of nifedipine subl. (20 mg, n = 9) and of verapamil p.o. (160 mg, n = 9) on the pressor effect of the unselective alpha-adrenergic agonist noradrenaline, as well as on 3H-yohimbine binding to platelet alpha 2-adrenoceptors was studied in patients with essential hypertension. In addition, the effect of nifedipine on reactivity to the selective alpha 1-adrenergic agonist phenylephrine was investigated (n = 9). Nifedipine caused a significant reduction of reactivity to noradrenaline (P less than 0.01), along with a significant decrease in binding sites (P less than 0.01). Affinity to the alpha 2-receptors was unchanged. Verapamil, although equally effective in lowering blood pressure, had no effect on the pressor response or binding sites. The pressor effect of the alpha 1-agonist phenylephrine was reduced (P less than 0.01) by nifedipine. Nifedipine may therefore affect both alpha 1- and alpha 2-adrenoceptors in patients with essential hypertension. Since verapamil did not affect the pressor response to noradrenaline or yohimbine-binding, the interaction with alpha 2-adrenoceptors does not appear to be a general prerequisite for the hypotensive action of calcium entry blockers.
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PMID:Effect of nifedipine and verapamil on alpha-receptor-activation in patients with essential hypertension. 610 Jul 53

The acute effects of two calcium channel blockers, nifedipine and verapamil, were compared in eight normotensive subjects and eight patients with essential hypertension. Nifedipine 10 mg and verapamil 160 mg orally had no effect on blood pressure of normal subjects, but reduced systolic and diastolic pressures of hypertensive patients to the same extent. The blood pressure reduction caused by nifedipine was more prompt and of lesser duration than that caused by verapamil. In both normal subjects and hypertensive patients nifedipine caused a transient rise in heart rate and plasma renin activity, and plasma catecholamines showed a tendency to increase; verapamil did not affect these variables. Nifedipine induced a marked increase in urine volume and renal sodium excretion in hypertensive patients, with a much smaller change in normotensives. Verapamil did not influence water and sodium excretion in either direction. Thus, this study shows similarities and differences between the effects induced by acute oral administration of the most-used vasodilating calcium antagonists.
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PMID:Comparison of cardiovascular, renal, and humoral effects of acute administration of two calcium channel blockers in normotensive and hypertensive subjects. 618 61


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