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

Amlodipine 10 mg once daily added to captopril 25 mg twice daily for 4 weeks in patients with moderate to severe hypertension significantly improved blood pressure control (by -18/-12 and -20/-12 mm Hg for supine and standing systolic/diastolic pressures respectively, p less than 0.001). Few side effects related to amlodipine were noted and none was serious.
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PMID:A double-blind crossover comparison of amlodipine and placebo added to captopril in moderate to severe hypertension. 246 37

Amlodipine, a long-acting calcium antagonist, was compared with hydrochlorothiazide (HCTZ) in a long-term study of 139 patients. After a 2-week placebo run-in period, patients were randomly allocated to receive either amlodipine or HCTZ in a 2:1 patient ratio. After study week 12, those patients whose hypertension was not controlled with either monotherapy had atenolol added to their regimen. The daily dose range for amlodipine was 2.5-10.0 mg and for HCTZ was 25-100 mg. At study week 12, 24-h postdose blood pressure was reduced in both amlodipine (-16/-12 mm Hg supine; -14/-12 mm Hg standing) and HCTZ (-16/-11 mm Hg supine; -16/-10 mm Hg standing) groups. Response was defined as a supine diastolic blood pressure of less than 90 mm Hg or its decrease by greater than or equal to 10 mm Hg. Responder rates at the end of 12 weeks' monotherapy were 74.1% for amlodipine and 69.8% for HCTZ. Forty percent of patients randomized to amlodipine and 45% randomized to HCTZ achieved adequate blood pressure control ("response" as defined above) with monotherapy alone over the whole 50-week treatment period. The incidence of treatment-related side effects up to study week 12 was 46.7% with amlodipine monotherapy and 25.5% with HCTZ monotherapy. Two patients were discontinued from amlodipine and one from HCTZ for side effects during the first 12 weeks of the study, and a further four from amlodipine after week 12; none were discontinued from combination therapy.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Long-term open evaluation of amlodipine versus hydrochlorothiazide in patients with essential hypertension. 246 39

Amlodipine, a new long-acting dihydropyridine calcium antagonist, was compared with hydrochlorothiazie (HCTZ) in 145 patients with mild to moderate hypertension. After 4 weeks of single-blind placebo runin, patients were randomly allocated to receive amlodipine (2.5-10 mg once daily, n = 97) or HCTZ (25-100 mg once daily, n = 48). At study week 12 response rates for amlodipine and HCTZ were 61.5 and 60.5%, respectively. There were clinically significant reductions in 24-h postdose blood pressures with both amlodipine (-18/-11 mm Hg supine: -14/-10 mm Hg standing) and HCTZ (-18/-10 mm Hg supine, -18/-9 mm Hg standing). After study week 12, atenolol (50-100 mg once daily) was added to the regimen of those patients whose hypertension was not controlled with monotherapy. Neither amlodipine nor HCTZ produced clinically significant changes in pulse rate, electrocardiogram, or chest x-ray film. Although amlodipine increased and HCTZ decreased the high-density lipoprotein (HDL)/total cholesterol ratio and the HDL/(low-density lipoprotein + very-low-density lipoprotein) ratio, the difference between the two treatments was not statistically significant. The incidence of side effects and the rate of patient withdrawal was comparable in the two groups. The incidence of laboratory abnormalities was 56% with HCTZ (mainly hypokalemia and hyperuricemia) and 16% with amlodipine. Amlodipine was an effective, well-tolerated agent for treatment of mild-to-moderate hypertension in this study, as single-daily-dose monotherapy and in combination with atenolol.
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PMID:Double-blind comparison of amlodipine and hydrochlorothiazide in patients with mild to moderate hypertension. 246 40

The antihypertensive efficacy and suitability for once daily dosing of amlodipine, a new calcium antagonist, was studied in a series of 205 patients with mild to moderate hypertension. The study was conducted double-blind in 13 centres. The starting doses of amlodipine were 1.25, 2.5 and 5 mg, respectively, which were doubled after 4 weeks if normotension or a preset target blood pressure was not reached. Target blood pressure was reached in 25% of patients with placebo, 41% with 2.5 mg of amlodipine, 56% with 5 mg of amlodipine and 73% with 10 mg of amlodipine once daily. The drug was well tolerated at all dose levels and no changes occurred in heart rate, body weight or electrocardiogram during treatment. Amlodipine is a useful new calcium antagonist for the treatment of hypertension producing smooth, dose-dependent blood pressure reductions with convenient once daily dosing.
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PMID:A dose-response study of amlodipine in mild to moderate hypertension. 252 34

Amlodipine is a potent calcium antagonist, inhibiting Ca2+-induced contractions of depolarized rat aorta with an IC50 of 1.9 nM. Unlike nifedipine, it displayed very slow association and dissociation with the calcium channel. The ability of amlodipine to inhibit Ca2+-induced contractions was strongly dependent on the K+ concentration present before the contraction, suggesting marked voltage dependence of action. Radioligand-binding studies in cardiac membrane preparations suggested that amlodipine may interact directly with both 1,4-dihydropyridine and diltiazem-binding sites on the calcium channel. Hemodynamic studies in anesthetized and conscious dogs showed that amlodipine is a coronary and peripheral vasodilator with a slow onset and long duration of effect, even when given by intravenous injection; the reflex stimulation of cardiac output, heart rate and myocardial contractility induced by amlodipine was attenuated by propranolol, but no marked negative inotropic or dromotropic effects were observed. Amlodipine was an effective oral antihypertensive agent in rat and dog models of hypertension, and its 24-hour duration of action in hypertensive dogs correlated well with its long plasma half-life in this species. The natriuretic properties displayed by amlodipine may contribute to its use as a first-line drug for the treatment of hypertension.
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PMID:Pharmacologic profile of amlodipine. 255 8

1. The antihypertensive efficacy of once-daily amlodipine was studied in a group of 30 patients with mild to moderate hypertension in a double-blind, placebo controlled parallel group study. The dose range of amlodipine was 2.5-10 mg daily titrated at 2 weekly intervals for a total treatment period of 8 weeks. 2. Amlodipine produced a significant reduction in blood pressure compared with placebo, the mean difference between baseline and 8 weeks (corrected for placebo effect) being 16/12 mm Hg supine, 14/4 mm Hg standing. 3. Blood pressure returned to baseline values during a terminal 4 week washout period on placebo. 4. There were no significant effects on heart rate. 5. Two patients experienced slight ankle oedema while receiving amlodipine 10 mg daily but the active drug was otherwise well tolerated. 6. Plasma concentration of amlodipine, sampled 24 h after the preceding dose, increased as the dose titration sequence was followed, averaging 2.5 ng ml-1 on 2.5 mg, 4.9 ng ml-1 on 5 mg and 10.5 ng ml-1 on 10 mg.
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PMID:Once daily amlodipine in the treatment of mild to moderate hypertension. 296 53

1. An investigation was undertaken to examine the effect of calcium channel blockade, induced by amlodipine, on the ability of the renal sympathetic nerves to cause an antidiuresis and anti-natriuresis in normotensive Sprague Dawley and spontaneously hypertensive rats anaesthetized with pentobarbitone. 2. Low frequency renal nerve stimulation in normotensive rats, which did not change renal blood flow, caused a 15% reduction in glomerular filtration rate and was associated with falls in urine flow of 37%, absolute sodium excretion of 47%, and fractional sodium excretion of 38%. The magnitude of these renal excretory changes was unaffected by prior administration of amlodipine at either 200 micrograms kg-1 plus 50 micrograms kg-1 h-1 or 400 micrograms kg-1 plus 100 micrograms kg-1 h-1. Amlodipine given in the higher dose, decreased basal levels of blood pressure and increased basal urine flow and sodium excretion. 3. In spontaneously hypertensive rats, renal nerve stimulation minimally affected renal haemodynamics but decreased urine flow, absolute and fractional sodium excretion by 29%, 31% and 24%, respectively. 4. Similar renal nerve stimulation in spontaneously hypertensive rats given amlodipine at 200 micrograms kg-1 plus 50 micrograms kg-1 h-1 or 400 micrograms kg-1 plus 100 micrograms kg-1 h-1 caused minimal changes in renal haemodynamics and in the excretion of water and sodium. The higher dose of drug resulted in decreased blood pressure and increased basal rates of urine flow and sodium excretion. 5. These data show that in spontaneously hypertensive rats but not normotensive rats, calcium channel blockade inhibited the ability of the renal nerves to stimulate the reabsorptive processes for sodium at the renal tubule. This indicated that in spontaneous hypertension the post-receptor mechanisms had changed and become more dependent on the inward movement of calcium.
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PMID:A study of the action of amlodipine on adrenergically regulated sodium handling by the kidney in normotensive and hypertensive rats. 296 97

The efficacy and tolerability of amlodipine (5 mg, once daily), nifedipine retard (20 mg, twice daily), and placebo were compared in a multicenter, three-way, crossover study involving 97 patients with mild-to-moderate hypertension. Each patient underwent three, 2-week treatment periods separated by 2-week washout periods without therapy. Comparable and significant (p < 0.05) blood pressure reductions were observed after amlodipine and nifedipine retard when compared with placebo, except in the case of supine systolic blood pressure with nifedipine retard. A significantly greater incidence of treatment-related side effects was observed with nifedipine retard (41%) compared with amlodipine (27%, p < 0.05) or placebo (16%, p < 0.01). Amlodipine treatment was associated with significantly fewer reports of headache and flushing than nifedipine retard (p < 0.05). The lower incidence and reduced severity of vasodilator side effects associated with amlodipine resulted in fewer withdrawals and a better overall tolerability profile.
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PMID:Side effects of dihydropyridine therapy: comparison of amlodipine and nifedipine retard. 752 87

The efficacy and safety of the novel calcium antagonist Amlodipine (Pfizer Laboratories, New York, New York) and hydrochlorothiazide were evaluated and compared in a randomized, single-blind, parallel group study in black Africans with essential hypertension. Twenty Nigerians with newly diagnosed mild to moderate essential hypertension were randomized to receive ascending doses of Amlodipine (5 mg and 10 mg) or hydrochlorothiazide (25 mg or 50 mg), and blood pressure and heart rate were measured at baseline and at 2, 4, and 6 weeks of therapy. Both Amlodipine and hydrochlorothiazide significantly reduced supine and erect blood pressure. Supine blood pressure on Amlodipine fell from a mean of 190/104 mm Hg to 150/79 mm Hg, and on thiazide from 180/103 mm Hg to 141/84 mm Hg. There was, however, no significant difference between both drugs in antihypertensive efficacy. Neither drug induced a reflex increase in heart rate. The fall in blood pressure on both agents was associated with an increase in plasma urea. Amlodipine induced no change in plasma potassium, but hydrochlorothiazide caused hypokalemia. Both agents were well tolerated, and Amlodipine should undergo further study in the treatment of hypertension in blacks.
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PMID:The efficacy and tolerability of amlodipine and hydrochlorothiazide in Nigerians with essential hypertension. 763 94

We compared the effects of 4 weeks of calcium channel blockade (amlodipine) or converting enzyme inhibition (lisinopril) on blood pressure and renal hemodynamics in a double-blind crossover trial in a group of 20 hypertensive cyclosporine-treated renal transplant patients. Amlodipine (10 mg) was more effective than the same dose of lisinopril in controlling hypertension (mean 24-hour arterial pressure, 111 +/- 9 and 115 +/- 9 mm Hg, respectively; P < .05). Blood pressure during both treatments was lower than during placebo (124 +/- 12 mm Hg, P < .05). Compared with placebo, amlodipine treatment was associated with a significant increase in glomerular filtration rate (10 +/- 20%, P < .05) and effective renal plasma flow (27 +/- 20%, P < .01) and a decrease in renal vascular resistance (23 +/- 18%, P < .01). Renal hemodynamics did not change during lisinopril. Neither drug had an effect on proteinuria. The data indicate that amlodipine is more effective than lisinopril in controlling hypertension in cyclosporine-treated patients and that treatment with amlodipine but not with lisinopril is accompanied by an increase in glomerular filtration rate and effective renal plasma flow and a decrease in renal vascular resistance. The data suggest that the renin-angiotensin system does not play a main role in determining cyclosporine-associated changes in renal hemodynamics and has a limited role in determining cyclosporine-associated hypertension.
Hypertension 1995 Jan
PMID:Hypertension after renal transplantation. Calcium channel or converting enzyme blockade? 784 58


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