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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 effects of the regular immediate release formulation of verapamil (verapamil IR) and the newer sustained release formulation of verapamil (verapamil SR) were compared in Hispanic patients with untreated essential hypertension. Verapamil IR was given in 3 divided doses (80 or 160mg 3 times daily) and verapamil SR was given either as a single daily dose of 240mg or as 240mg every 12 hours. With both formulations there was a significant reduction in systolic (SBP) and diastolic blood pressure (DBP); a greater lowering of BP was observed with verapamil 480 mg/day than with 240 mg/day. With verapamil SR 480 mg/day, 91% of patients had reductions in SBP and DBP greater than 20 and 15mm Hg, respectively. In addition, 83% of patients reached normotension. With the lower dose (240mg once daily), 83% of patients had decreases in DBP greater than 10mm Hg and 73% of patients achieved normotension. Comparable effects were achieved with verapamil IR. With verapamil IR there was a more rapid fall in BP which peaked 3 to 4 hours postdose, whereas with verapamil SR a more gradual and sustained BP reduction was observed. Only small changes in heart rate (HR) were observed with verapamil IR and verapamil SR. For verapamil SR, the mean increase in HR was 5 beats/min (to 80 beats/min) and the mean decrease in HR was 13 beats/min (to 62 beats/min). Both verapamil SR and verapamil IR prolonged the PR interval of the ECG. An equal degree of PR prolongation was observed with 240 and 480 mg/day. The incidence of side effects (headache, palpitations, dizziness and flushing) was dose dependent, decreased with continuous treatment and was much higher with verapamil IR than with verapamil SR. Steady-state plasma verapamil concentrations were monitored. Compared with verapamil IR, verapamil SR produced a more gradual rise and a more sustained elevation of plasma verapamil and norverapamil concentrations. Comparable trough verapamil concentrations (Cmin) were observed with verapamil IR (98 micrograms/L) and SR (81 micrograms/L); morning Cmin verapamil concentrations were higher than daytime Cmin values. The normalised area under the plasma concentration-time curve (AUC) and maximum concentration (Cmax) were 10 to 20% greater for verapamil IR than SR. The 2-fold increase in oral dose produced a 2.2- and 2.4-fold increase in AUC for verapamil IR and SR, respectively, associated with a 20% reduction in metabolism to norverapamil. Fasting increased the rate and extent of absorption of verapamil.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Comparative efficacy, safety and pharmacokinetics of verapamil SR vs verapamil IR in hypertensive patients. 128 70

Animal experiments have shown that the administration of calcium antagonists can prevent or slow the progression of atherosclerosis by inhibiting calcium overload and interfering with lipid metabolism and deposition. These encouraging results have prompted clinical trials to evaluate the effects of calcium antagonists (dihydropyridines and diphenylalkylamines) on atherosclerotic plaque formation. In patients with coronary heart disease, several studies have already shown that calcium antagonists can have a positive effect on plaque evolution, while in hypertensive patients no such study has been published to date. The Verapamil in Hypertension Atherosclerosis Study is an ongoing multicentre randomised double-blind parallel group trial comparing the antihypertensive efficacy of verapamil SR 240 mg/day with that of chlorthalidone 25 mg/day in 1464 patients with essential hypertension aged 40 to 65 years. In a randomised subgroup of patients (n = 550), who will be followed up for 3 years, B-mode ultrasonography is being employed to evaluate the effects of the 2 drugs on carotid wall thickness and carotid plaque development. Ultrasonographic evaluations are performed at baseline, after 3 months, and 1, 2 and 3 years after a standardised protocol to determine intimal-medial thickness in 4 segments of the extracranial carotid tree. The most interesting result to date is the high incidence of carotid alterations, with plaques present in 35% and arterial wall thickening in 31.8% of the 311 asymptomatic hypertensive patients processed so far. A preliminary evaluation of the antihypertensive efficacy of the trial medications after 6 months of double-blind treatment indicates a 63.5% response rate to monotherapy and a 7.8% drop-out rate because of drug inefficacy or intolerance.
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PMID:Preliminary clinical experience with calcium antagonists in atherosclerosis. Verapamil in Hypertension Atherosclerosis Study Investigators. 128 76

Information is limited regarding the efficacy of antihypertensive drugs in patients with hypertension associated with renal insufficiency. To address this question, a group of 14 outpatients with essential hypertension and mild renal insufficiency received slow release verapamil 240 mg/day for 14 days after a 4-week washout period. Patients were randomly assigned to a low (4 g/day) or high (11 g/day) salt diet, and crossed over to the alternative diet after 7 days. 24-Hour blood pressure monitoring was performed at the end of the washout period and after 7 and 14 days during verapamil treatment. Verapamil induced a significant fall in mean 24-hour blood pressure that was similar for patients on both diets (p < 0.01). As expected, natriuresis increased significantly during high sodium intake (p < 0.01), and bodyweight fell significantly when sodium intake was reduced (p < 0.05). Meanwhile, serum creatinine and creatinine clearance remained stable. These results indicate that the antihypertensive effect of verapamil is independent of sodium intake even in the presence of mild renal insufficiency.
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PMID:Sodium intake does not influence the effect of verapamil in hypertensive patients with mild renal insufficiency. 128 91

A multicenter open trial involving 50 hypertension patients enabled evaluation of the efficacy and tolerability of Isoptine L.P. (sustained release verapamil) in mild to moderate essential hypertension. Following a 2-week placebo run-in period, patients were given Isoptine L.P. (240 mg/24 h) as a morning dose for 3 months, with a possible dose increase (360 mg/24 h) in case of diastolic blood pressure of 95 mmHg or more at the 30-day evaluation. Blood pressure was measured by mercury sphygmomanometer and, in 20 patients, by a Dinamap type Automatic device. After 3 months of treatment, blood pressure levels in supine and standing position, measured manually and automatically, showed a highly significant decrease, with a mean fall of 18.4 mmHg for systolic (13.7 percent) and 13.2 mmHg diastolic (-14.6 percent). 67 percent of patients were responders after 1 month of treatment and 79 percent at 3 months, including one-fifth at the dose of 360 mg/24 h. Seventeen patients, i.e. 34 percent, reported one or more adverse reactions. Among these, four patients had to stop treatment, twice because of headache and twice for constipation. Adverse events seen most frequently were constipation, headache, tiredness and vomiting. No cardiac adverse events were reported with the exception of one case of atrial premature contractions. The electrocardiogram revealed significant slowing of heart rate, as well as slight prolongation of PR and QT intervals and slight widening of the QRS complex. Tolerability on the basis of laboratory parameters was good.
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PMID:[Efficacy and tolerability of isoptine LP in mild to moderate hypertension. A multicenter study with 50 patients]. 130 Sep 22

An open study in 25 patients evaluated the efficacy and safety of Isoptine S.R., in some cases associated with Aldactazine in mild to moderate essential hypertension. After a placebo period of 2 weeks, the patients received sustained release verapamil (240 mg/24 hours) in a single morning dose for 6 months. An increase in the dosage (360 mg/24 hours in two subdoses) could be made during the first month of treatment if the diastolic blood pressure remained greater than or equal to 95 mmHg. If the diastolic blood pressure persisted at these levels at the second monthly assessment, a tablet of Aldactazine was associated. The blood pressure was evaluated by means of conventional clinical determinations and 24-hour ambulatory recordings carried out at the time of inclusion and then after 3 and 6 months of treatment. From the first month of treatment, the casual blood pressure determinations in the supine and standing position fell highly significantly (p less than 0.0001), resulting in a mean reduction of 22.3 mmHg in the systolic blood pressure (-12.6%) and of 17.4 mmHg in the diastolic blood pressure (-17%). The ambulatory recordings of blood pressure also showed a significant reduction in the mean systolic blood pressure over 24 hours (p less than 0.05 at the 3rd month of treatment), in the mean diastolic blood pressure over 24 hours (p less than 0.01) and the mean pressure (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Sustained-released verapamil and ambulatory recording of blood pressure in mild to moderate essential hypertension]. 156 57

The calcium antagonists are valuable and widely used agents in the management of essential hypertension and angina. There is an increasing number of new agents to add to the 3 prototype substances nifedipine, diltiazem and verapamil. These new agents are dihydropyridines structurally related to nifedipine. However, they tend to have longer elimination half-lives (t 1/2 beta) and may be suitable for twice-daily administration. Amlodipine is an exception with a t 1/2 beta in excess of 30h. Apart from elimination rates, however, the pharmacokinetic characteristics of the newer agents have a notable tendency to resemble those of the established agents. They are highly cleared drugs, are relatively highly protein bound. As they are subject to significant first-pass metabolism, old age and hepatic impairment will increase their plasma concentrations due to a reduced first-pass effect. Renal impairment does little to their pharmacokinetics since the fraction eliminated unchanged by the kidney is small. For most agents, plasma concentration-response relationships have been described. Interesting areas for further research include chronopharmacokinetics, stereoselective pharmacokinetics and lipid solubility. Drugs affecting hepatic blood flow and drug metabolising capacity have predictable interaction potential. Some of the newer calcium antagonists will, like verapamil, increase plasma digoxin concentrations. Verapamil and diltiazem decrease phenazone (antipyrine) metabolism and therefore tend to decrease the metabolism of other drugs.
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PMID:Clinical pharmacokinetics of calcium antagonists. An update. 158 55

We have studied the effect of atenolol, xipamide, and verapamil in the control of effort tensional response in 54 patients suffering essential hypertension. A first effort test without treatment and a second after a one month treatment randomly assigned were performed in all patients, evaluating the tensional response at 30, 60 and 80 Watts of charge, maximum peak, and after five minutes in recovery. Atenolol significantly reduced (p less than 0.05) systolic arterial pressure and diastolic arterial pressure in every intermediate effort stage, maximum peak and post effort recovery, xipamide, also significantly reduced (p less than 0.05) the systolic hypertensive response at all different levels, however, the diastolic one did not reach any statistic significance. Verapamil at used doses did not modify neither systolic nor diastolic hypertensive response. The beneficial effect of beta-blockers is confirmed although we could not confirm the effect pointed out by other authors regarding calcium antagonists. Tensional control using xipamide was striking although there is some evidence to think that it can have a more important effect in the control than thiazide diuretics or amiloride.
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PMID:[Study of blood pressure response to exertion in essential hypertension. Its modification with anti-hypertensive treatment]. 178 56

By using apexcardiography and echocardiography, the diastolic and systolic function of 34 hypertensive patients were studied. The results indicated that left ventricular (LV) hypertrophy is one of the important factors in impairing LV diastolic function in essential hypertension. By using self-control method, Verapamil(V) was injected intravenously. Relative A wave to total diastolic amplitude (A/D), total apexcardiographic relaxation time index (TARTI), diastolic amplitude time index (DATI) and PEP/LVET were measured. After 5 half-lives of V, intravenous Tetrandrine (T) was given, all the measurements were repeated in the same way. The data revealed that A/D, TRATI and DATI improved significantly after intravenous T and V as well, yet PEP/LVET showed no significant change. It, therefore, seems clear that both T and V could induce a significant improvement in LV diastolic function without any apparent adverse influence on systolic function.
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PMID:[Effect of tetrandrine and verapamil on left ventricular diastolic and systolic function in essential hypertension]. 187 78

Calcium antagonists are popular therapeutic agents in the treatment of systemic hypertension. Although these agents have similar antihypertensive efficacy, they have varied effects on left ventricular function at rest in hypertensive patients. The effect of different calcium antagonists on left ventricular function during exercise and on exercise performance in patients with hypertension, however, is less clear. Fifteen patients with essential hypertension (diastolic blood pressure = 95 to 110 mm Hg) were enrolled in a placebo-controlled, single-blinded crossover study comparing nifedipine with verapamil for rest/exercise heart rate and blood pressure, exercise performance, and rest/exercise left ventricular function. Each drug was titrated to achieve resting diastolic pressures less than 90 mm Hg. All patients underwent maximal exercise testing and rest/exercise gated radionuclide ventriculography at the end of 3-week placebo, nifedipine, and verapamil treatment periods. Both calcium antagonists significantly reduced blood pressure at rest and during exercise compared with placebo. Neither calcium antagonist altered resting heart rate; however, both verapamil and nifedipine significantly reduced heart rate at maximal exercise. Verapamil but not nifedipine impaired left ventricular peak emptying rate and left ventricular peak filling rate during exercise but not at rest. Neither verapamil nor nifedipine, however, significantly altered rest or exercise global left ventricular ejection fraction (LVEF) compared with placebo. There was a trend, however, for impairment in the LVEF response to exercise (delta LVEF) in the verapamil treatment group. Exercise capacity was not significantly altered by either calcium antagonist compared with placebo. Thus verapamil but not nifedipine impairs left ventricular function during exercise in hypertensive patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Verapamil but not nifedipine impairs left ventricular function during exercise in hypertensive patients. 230 6

From a hemodynamic point of view, the calcium antagonists represent an interesting way of treating hypertension, because they reduce total peripheral resistance without compromising cardiac output. Blood flow is also maintained during muscular exercise. Verapamil and diltiazem induce slight reduction in heart rate, but this is compensated by increase in stroke volume. Verapamil and diltiazem also prolong atrioventricular conduction time, in contrast to the dihydropyridines. Most clinical data are available for verapamil, diltiazem, and nifedipine. In patients with mild-to-moderate hypertension, these compounds seem as effective as diuretics and beta-blockers. They do not induce disturbances in glucose metabolism, serum uric acid, or serum potassium, and unwanted disturbances in blood lipids have not been described. The dihydropyridines may safely be combined with beta-blockers, but the combination of either verapamil or diltiazem with a beta-blocker should be avoided (because of the high risk of bradycardia). The calcium antagonists seem particularly useful in patients with the combination of hypertension and angina pectoris or peripheral vascular diseases or chronic obstructive lung diseases or diabetes. They are also effective in hypertensive crises. They may also be tried as a first line drug in patients with mild and moderate essential hypertension, particularly when diuretics or beta-blockers are contraindicated. Temporary side effects due to vasodilatation (headache, flushing, and palpitations) are seen frequently, particularly on the dihydropyridines. Edema is the most frequent serious side effect of the dihydropyridines, and constipation is most common with verapamil. At this point, few long-term data are available and it is not known whether the calcium antagonists will give better or worse results, with respect to morbidity and mortality, than the beta-blockers, diuretics, or other more recent antihypertensive agents.
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PMID:Clinical use of calcium antagonists in hypertension: update 1986. 245 35


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