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 9,689 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

The efficacy of sustained release verapamil (Ikapress) was investigated in 237 hypertensive patients of both sexes in a multicenter trial in family practice. There were 4 groups: patients without previous treatment and those treated with nifedipine, with atenolol, or with a combination of drugs. After 4-7 days of washout, all those with diastolic pressures of 95 mm Hg or above received once daily 240 mg of verapamil for 8 weeks. 27 cases had to be withdrawn because of adverse effects: weakness in 10, constipation in 6, rash in 4, impotence in 3, and in 4, other reasons. In 177 blood pressure was brought under control after 4 weeks of treatment. An additional 33 were controlled after 4 weeks of 360 mg of sustained release verapamil. Response to treatment was similar in the 4 trial groups. Mean systolic and diastolic pressures fell 19 and 16 mm Hg, respectively, and mean pulse rate decreased by 5 beats/min. Constipation was the only side-effect reported by those who completed the trial. However, there was a significant reduction in initial scores for headache, dizziness, numbness and edema after 8 weeks of verapamil and all indices of quality of life were significantly improved. These included scores for general well-being, physical fitness, social activity, job fitness, sexual activity, sleep, concentration and mood. Scores for daytime sleepiness and fatigue also decreased significantly. Thus, sustained-release verapamil in a daily dose of 240-360 mg was shown to be an effective antihypertensive. It had few adverse effects and gave considerable improvement in quality of life.
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PMID:[Sustained release verapamil in essential hypertension]. 193 92

In an open multicenter trial (uncontrolled study) in 4,247 patients (49.1% male, 50.9% female; aged 17-89 years) with mild, moderate, or severe hypertension, the antihypertensive efficacy and in particular the tolerability of verapamil slow-release (SR) 240 mg (Isoptin RR) were studied. The dosage of the drug was adjusted to the therapeutic response; in 88.7% of the patients it was titrated according to the study protocol: 63.2% received constantly one SR tablet throughout the 6-week treatment period; in 15.6% the dosage was increased to one and a half tablet after 2 weeks, and in 9.9% to one tablet b.i.d. after a further 2 weeks. Monotherapy with verapamil SR 240 mg normalized diastolic blood pressure (less than or equal to 90 mm Hg) in 90% of the patients with mild hypertension, 77% of those with moderate, and 61% of those with severe hypertension. It was evident that blood pressure reduction was more pronounced the higher the baseline value. Cardiac and extracardiac tolerability of verapamil SR 240 mg was good. Mean heart rate was slightly reduced, none of the patients developed a second- or third-degree atrioventricular block. Side effects were reported by 480 of the 4,247 patients (11.3%). As expected, constipation (4.03%) was the predominant adverse reaction, followed by dizziness (3.65%), headache (1.54%), and other (less than 1%). In 217 patients (5.1%) therapy was discontinued prematurely, in 139 (3.27%) because of side effects.
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PMID:Efficacy and safety of verapamil SR 240 mg in essential hypertension: results of a multicentric phase IV study. 247 86

Calcium channel blocking drugs are a chemically heterogenous group, so it might be expected that their effects on vascular smooth muscle, cardiac contractility, and conduction tissue may differ. However, the majority of adverse reactions are predictable from their pharmacological actions and may be conveniently grouped in the following categories: 1) vasodilatation, 2) negative inotropic effects, 3) conduction disturbances, 4) gastrointestinal effects, 5) metabolic effects, and 6) drug interactions. Vasodilatory symptoms, namely, dizziness, headaches, flushing sensation, and palpitation, are more likely with nifedipine. Peripheral edema is also common with nifedipine, but the mechanism is uncertain. For a given degree of vasodilation, the greatest negative inotropic effect is seen with verapamil first, diltiazem second, and nifedipine last. Calcium channel blocking drugs are contraindicated in hypertensive patients with second and third degree heart block, sick sinus syndrome, and severe heart failure. Verapamil and diltiazem have a significant effect on cardiac conduction, whereas nifedipine, in therapeutic doses, does not. Local gastrointestinal symptoms, such as nausea and constipation, are common with verapamil. None of the calcium channel blocking drugs have been reported to adversely affect lipid or protein metabolism. However, nifedipine, verapamil, and diltiazem in high doses may inhibit liberation of insulin. The significance of this finding needs to be explored further in hypertensive diabetics. Serum digoxin levels have been shown to increase after administration of verapamil and nifedipine, but there is no evidence that this change has any clinical relevance.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Side effects of calcium channel blockers. 328 Apr 92

We compared verapamil and propranolol hydrochloride for monotherapy of hypertension. Verapamil lowered blood pressure (BP) more effectively than propranolol in black and white patients. Verapamil was equally effective in blacks and whites, whereas propranolol was more effective in whites. Heart rate was reduced by 6.0 beats per minute by verapamil, and by 13.6 beats per minute by propranolol. In blacks, verapamil lowered systolic BP 16.9 vs 8.1 mm Hg for propranolol; verapamil reduced diastolic BP 12.8 vs 8.6 mm Hg for propranolol. In whites, verapamil lowered systolic BP 19.0 vs 12.7 mm Hg for propranolol; verapamil reduced diastolic BP 16.7 vs 12.3 mm Hg for propranolol. Increases in systolic BP were observed in 22% and 3.4% of patients receiving propranolol and verapamil, respectively. The PR interval was increased from 163.5 to 174.9 ms for verapamil vs 160.3 to 164.4 ms for propranolol. Constipation (15%) and headaches (10%) were most frequent complaints for verapamil vs fatigue (18%) and dizziness (7%) for propranolol. Changes in blood biochemistry values were of small magnitude. We conclude that verapamil monotherapy is a safe and effective means of achieving BP control in patients with essential hypertension.
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PMID:A comparison of verapamil and propranolol for the initial treatment of hypertension. Racial differences in response. 353 60

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 pharmacokinetics, clinical efficacy, and adverse effects of three calcium-channel blocking agents--verapamil, nifedipine, and diltiazem--are reviewed. Verapamil, nifedipine, and diltiazem are absorbed well after oral dosing, but absolute bioavailability of each is reduced substantially by a first-pass effect. Each drug is metabolized extensively (verapamil and diltiazem to moderately active metabolites) by the liver. A substantial percentage of each drug is bound to plasma proteins, but the binding is of clinical importance only for nifedipine (92--98% protein bound). Intravenous verapamil has become the agent of first choice for treatment of acute paroxysmal supraventricular tachycardia (PSVT); use of chronic oral verapamil therapy for prophylaxis remains controversial. Verapamil and diltiazem have been evaluated with mixed results for atrial flutter and fibrillation. For treatment of myocardial ischemia, calcium-channel blockers may be of some value (possibly in combination with nitrates of B blockers). All three agents have been studied in patients with exertional angina with good results. Calcium-channel blockers appear to be equal with nitrates for treatment of variant angina. Patients with hypertropic cardiomyopathy have been treated with verapamil and nifedipine with promising results. Nifedipine has been effective for treatment of essential hypertension. Adverse effects of calcium-channel blockers have been relatively minor or infrequent. Diltiazem overall has the best side-effect profile, with adverse effects causing discontinuation of therapy in about 2--10% of patients; verapamil in intermediate (8--10%) and nifedipine the worst (17%) in this respect. The most common side effects generally are fatigue, headache, dizziness, skin rash, and peripheral edema. While they generally should be reserved for patients in whom more conventional therapy has failed (except those with PSVT), calcium-channel blockers appear to have a valid role as reserve agents for exertional and variant angina, cardiomyopathy, and hypertension.
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PMID:Update on calcium-channel blocking agents. 635 66

Verapamil hydrochloride, a prototype calcium antagonist, is now marketed in the United States for the acute treatment of supraventricular tachyarrhythmias and for chronic management of vasospastic and chronic stable angina. It inhibits the slow inward channel in in the heart and blocks calcium influx in smooth muscle. Its intrinsic negative inotropic action, which is apparent in isolated tissues, is offset in vivo by peripheral vasodilation. It has a mild, noncompetitive sympathetic antagonist effect; its most important electrophysiologic action is a depression of AV nodal conduction, accounting for its effect in supraventricular tachyarrhythmias. Its hemodynamic actions are characterized by a complex interplay of changes in preload, afterload, contractility, heart rate, and coronary blood flow. It does not depress cardiac function, except in severe heart failure. The drug has a mild dilator action on coronary arteries and reverses ergonovine-induced vasoconstriction. Controlled trials have established its role in Prinzmetal's variant angina, unstable angina, and chronic stable angina. It has also been found to be effective in obstructive cardiomyopathies. The potential role of verapamil in such conditions as hypertension, cardioprotection, and Raynaud's phenomenon needs further evaluation; at present these indications have not been approved by the Food and Drug Administration. The most common side effects include constipation, skin rash, and dizziness; AV block, heart failure, and sinus arrest may occasionally be encountered, especially when ventricular function is compromised or conduction system disease is present.
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PMID:Verapamil hydrochloride: pharmacological properties and role in cardiovascular therapeutics. 676 30

Isoptin SR was used in 65 essential hypertensive patients. 240mg Isoptin SR (German Knoll Pharmaceutical company) per day was used in group A (35 cases) for 6 weeks, and in group B (30 cases) for 24 weeks, BP in group A and B decreased obviously in the first and second week after treatment. Marked effective rate and total effective rate were 65.7% and 74.3% respectively in group A, and 70.0% and 83.3% in group B. There were no significant changes of HR in group A before and after treatment while there was a decrease of HR in group B (P < 0.001). Left atrium (LA) decreased after 6 weeks in group A with an obvious increase of E/A ratio. There was significant decrease in LA, increase in E/A ratio, regression of IVS, LVPW and LVMI, but no changes in SV, CO, LVEF after 24 weeks of treatment of Isoptin SR in group B. E/A ratio was very sensitive and occurred earliest both in group A and group B. Side effects such as headache, dizziness, constipation, insomnia, peripheral oedema, sinus bradycardia occurred mainly in the first week of treatment. These symptoms disappeared gradually in the course of continued administration of Isoptin SR.
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PMID:The effect of Isoptin SR on blood pressure, heart function and hypertrophy of left ventricle of hypertensive patients. 808 92

Arterial hypertension, especially when co-exists with ischemic heart disease, makes an important clinical and social problem. Necessity to continue a treatment during the whole patients life produces many problems for a patient himself as well as for a physician. Thus, for many years, researches have been carried out to find a medicine that would allow to fully control blood pressure for all day, would have minimal side-effects and could be administered once a day. Beside convertase inhibitors such as Prestarium and Gopten, calcium channel blockers, especially retard verapamil forms like Isoptin SR-240 and SR-120 seem to be the most appropriate medicines, especially when hypertension is accompanied by ischemic heart disease and dysrrythmias. The study was performed in 150 hypertensive patients who were administered Isoptin SR-240 once a day and Isoptin SR-120 twice a day. That dose was sufficient to normalize benign and mild hypertension in most patients. Decreased frequency of dyshrrytmias and chest pain relief were also observed. Trials to increase daily dose up to 360 mg were accompanied by evident side effects such as dizziness and constipations. Much more profitable was to join lower Isoptin dose with convertase inhibitors and diuretics.
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PMID:[Isoptin SR-240 and SR-120 in ambulatory treatment of arterial hypertension]. 875 74


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