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

The effects of the calcium entry blocker nitrendipine on blood pressure (BP) and renal hemodynamics were studied in rats with angiotensin II (ANG II)-induced hypertension. The ANG II was infused subcutaneously by implanted osmotic minipumps for 14 to 16 days. There was a progressive rise in BP in ANG II-infused rats to levels 58 mm Hg above basal by Day 10, whereas control rats with sham pumps remained normotensive. Nitrendipine or vehicle was administered by gavage to groups of control and hypertensive rats for 5 days, and clearance experiments were performed with the rats under anesthesia on the last day. The prolonged infusion of ANG II increased the renal vascular resistance and reduced the glomerular filtration rate and renal Na+ excretion. At a dose of 3 mg/100 g body weight, nitrendipine had no consistent effects on BP or renal function of control rats. By contrast, in rats with ANG II-induced hypertension, nitrendipine normalized both the BP and the changes in renal vascular resistance and glomerular filtration rate. Despite the fall in BP, nitrendipine caused a marked diuresis and natriuresis. Moreover, nitrendipine increased Na+ excretion of conscious, ANG II-hypertensive rats but not of controls. Thus, nitrendipine appears to be highly effective in reversing ANG II-induced hypertension and Na+ retention. These findings also indicate that the hypertension, renal vasoconstriction, and Na+ retention accompanying prolonged ANG II infusions may be mediated by calcium-dependent mechanisms.
Hypertension
PMID:Effects of a calcium entry blocker on blood pressure and renal function during angiotensin-induced hypertension. 315 2

To test the hypothesis that the antihypertensive effect of the calcium channel blocking drug nitrendipine is in part related to natriuresis, we gave 16 subjects (8 normal, 8 hypertensive) placebo for 8 days followed by nitrendipine titrated to 20 mg twice daily for 8 days. The same diet was prepared for each meal for the entire study. Sodium intake was fixed for each subject and averaged 150 mEq/day. All urine was collected every day. Blood was drawn at the end of the placebo and nitrendipine periods for renin, aldosterone, and norepinephrine values. Nitrendipine caused a significant increase (p less than 0.05) in cumulative sodium excretion of 161 mEq over 7 days in the normal subjects and 103 mEq in hypertensive subjects. Potassium excretion was unaffected. In both hypertensive and normal subjects, plasma renin and plasma norepinephrine activity increased significantly (p less than 0.05), while plasma aldosterone levels did not change. Upright systolic blood pressure decreased significantly (p less than 0.05) in both groups, whereas upright diastolic blood pressure decreased only in hypertensive subjects. We conclude that blood pressure lowering effects of this drug may be in part related to natriuresis and that calcium channel blockade may dissociate plasma renin activity from that of aldosterone.
Hypertension
PMID:Calcium channel blockade with nitrendipine. Effects on sodium homeostasis, the renin-angiotensin system, and the sympathetic nervous system in humans. 315 5

The effects of nitrendipine, 8 micrograms/kg/minute, were evaluated in six conscious dogs through measurements of arterial pressure and blood flow in the ascending aorta (cardiac output), mesenteric, renal, and iliac arteries before and after induction of chronic perinephritic hypertension. Before hypertension was induced, nitrendipine reduced mean arterial pressure 19 +/- 2.3% (from 95 +/- 3.2 mm Hg), decreased total peripheral resistance (60 +/- 2.6%), and increased cardiac output (108 +/- 10.5%). These values returned to baseline within 15 to 30 minutes. Nitrendipine caused the greatest increase in blood flow in the iliac bed (98 +/- 9.9%), an intermediate increase in the mesenteric bed (37 +/- 3.7%), and the least increase in the renal bed (7 +/- 2.2%). Two to six weeks after induction of hypertension, administration of nitrendipine elicited significant (p less than 0.01) decreases in mean arterial pressure (32 +/- 2.5% from 151 +/- 4.8 mm Hg) and total peripheral resistance (67 +/- 1.3%) compared with its administration in normotensive dogs, while the increase in cardiac output was not significantly changed (111 +/- 10.9%). These changes in arterial pressure and vascular resistances also were prolonged (i.e., hemodynamics returned to baseline after 75-90 minutes). The increase in iliac (99 +/- 16.8%) and renal (9 +/- 6.1%) blood flows after nitrendipine administration in hypertensive dogs was similar to that found in the normotensive dogs, but mesenteric blood flow doubled (84 +/- 8.4%). Thus, in conscious, hypertensive dogs, nitrendipine administration appears to markedly decrease arterial pressure and total peripheral and regional resistances, which also require more time to return to baseline, but appears to increase blood flow by a greater amount only in the mesenteric bed.
Hypertension
PMID:Effects of a calcium channel blocker on cardiac output distribution in conscious hypertensive dogs. 315 3

To assess the clinical efficacy of chronic nitrendipine therapy in mild to moderate essential hypertension, we studied blood pressure (BP) and heart rate responses in 22 subjects receiving maintenance nitrendipine therapy. Ten subjects (45%) whose hypertension was controlled with chronic monotherapy had an 11/12 mm Hg decrease in supine BP (P less than 0.05) with a mean (+/- SD) dose of 71 +/- 15 mg/day. The 12 (55%) subjects whose hypertension was not controlled with monotherapy had a comparatively higher baseline BP than the other 10 (156/105 +/- 10/6 compared with 150/98 +/- 15/4 mm Hg; P less than 0.05). Eight of the 10 subjects demonstrating office BP control with chronic nitrendipine monotherapy who also had full-time employment underwent continuous ambulatory BP monitoring before and after maintenance monotherapy. Nitrendipine induced a reduction in the mean 24-hour BP and mean BP at home, but did not reduce the BP during work or while asleep. These data suggest that nitrendipine lowers BP when assessed by casual office methods. The ambulatory BP monitor data demonstrate that the hypotensive response to chronic nitrendipine is modified during work periods, which are generally associated with increased adrenergic activity. Ambulatory BP monitoring may be superior to office (casual) monitoring in the assessment of the overall efficacy of antihypertensive drugs.
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PMID:Effects of chronic nitrendipine on casual (office) and 24-hour ambulatory blood pressure. 315 31

The efficacy and safety of long-term treatment with oral nitrendipine were evaluated in 34 patients with essential arterial hypertension. Nitrendipine alone significantly lowered systolic and diastolic blood pressure levels in 28 patients who completed the preliminary four-week dose-setting phase. Twenty-one patients completed the one-year treatment. Blood pressure control was maintained by nitrendipine alone in 11 patients. Ten patients not adequately controlled at the end of the dose-setting phase were successfully treated with nitrendipine combined with acebutolol or muzolimine. It is concluded that nitrendipine is a promising calcium antagonist for the treatment of arterial hypertension.
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PMID:Long-term treatment of essential arterial hypertension with nitrendipine. 327 64

Nitrendipine is a new dihydropyridine derivative developed specifically for the treatment of hypertension. Oral nitrendipine was administered to twelve patients with severe hypertension (diastolic blood pressure greater than 114 mm/Hg). All antihypertensive drugs were discontinued at least 72 hours prior to nitrendipine administration. The initial dose of nitrendipine was 5 mgs. orally twice daily which was titrated at 2 to 5 day intervals up to a maximum dose of 40 mgs. twice a day. Average pretreatment blood pressure (+/- SD) was 194/118 (28/3) mm/Hg and was 191/122 (25/9) mm/Hg standing. After 7 to 10 days of nitrendipine monotherapy, the average blood pressure had decreased to 170/102 (20/9) mm/Hg supine and 167/106 (19/8) mm/Hg standing. Thirty days of nitrendipine therapy resulted in a further decrease of average blood pressure to 159/96 (18/7) mm/Hg supine and 154/99 (12/12) mm/Hg standing. Average supine pulse (+/- SD) increased from 79.0 (13.9) to 90 (15.7) beats/min. after 7-10 days and to 82 (17) beats/min. after 30 days of therapy. The average total daily dose of nitrendipine was 47.5 mgs. after 30 days. Side effects were minimal and the medication was well tolerated by most patients. It was concluded that nitrendipine is a potent and effective antihypertensive agent in patients with severe hypertension.
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PMID:Nitrendipine monotherapy in severe hypertension. 334 10

A study of 31 patients with mild or moderate hypertension and 17 patients with severe hypertension was conducted to evaluate the long-term safety and efficacy of nitrendipine, a new calcium channel blocker with a long duration of action. Nitrendipine (5-40 mg bid) was given as monotherapy or in combination with hydrochlorothiazide and/or propranolol. Seventeen patients (54%) with mild to moderate hypertension were controlled with nitrendipine alone, but all except one patient with severe hypertension required combination therapy. In patients with mild or moderate hypertension, nitrendipine reduced supine blood pressure from a baseline mean 154/100 mm Hg to 136/87 mm Hg after 1 year of treatment (P less than .05). In patients with severe hypertension, supine blood pressure was reduced from 186/124 mm Hg to 148/91 mm Hg by the end of the planned treatment period (P less than .05; mean duration, 10 weeks). During extended observation, antihypertensive effect was sustained for up to 2.5 years and 1.6 years in patients with mild or moderate and severe hypertension, respectively. Nitrendipine was well tolerated; and only one patient, a moderate hypertensive, discontinued treatment because of pedal edema. The results of this long-term study show that nitrendipine alone or in combination with a diuretic and/or a beta blocker is a safe and effective agent for the treatment of patients with all degrees of hypertension.
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PMID:Long-term antihypertensive effects and safety of nitrendipine in patients with mild, moderate, and severe hypertension. 343 66

During the past 2 decades, encouraging strides have been made in the recognition and treatment of patients with high blood pressure and in the development of antihypertensive therapy. Concerns surrounding the control of hypertension, however, continue to emerge. As many as two-thirds of hypertensive patients in the US remain inadequately controlled. Although overall cardiovascular mortality has declined since the mid- 1960s, a significant impact of antihypertensive therapy on coronary artery disease morbidity and mortality has not been conclusively demonstrated. Unfavorable metabolic effects associated with traditional step-care antihypertensive therapy with diuretics and beta blockers are increasingly implicated for failure to demonstrate a decrease in coronary artery disease. The availability of newer efficacious antihypertensive therapy that does not adversely affect metabolic parameters is resulting in a reappraisal of traditional step-care. Of particular interest are the calcium channel blockers, because they are efficacious, well tolerated and offer favorable metabolic and hemodynamic profiles. Nitrendipine is a new long-acting member of the 1,4 dihydropyridine class of calcium channel blockers that has shown encouraging results for treatment of hypertension.
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PMID:Current therapy, present limitations and future goals for systemic hypertension. 353 51

Nitrendipine is a calcium entry blocker shown to inhibit the movement of calcium through the 'slow channel' of cardiac and vascular smooth muscle, thus inducing peripheral vasodilation with consequent reductions in elevated blood pressure. As evidenced by clinical trials, nitrendipine promptly lowers blood pressure in patients with mild to moderate hypertension, and sustains this effect during long term administration. Combining nitrendipine with other antihypertensive agents such as diuretics or beta-blockers often results in successful treatment in patients unresponsive to nitrendipine monotherapy. Headache, oedema, flushing and palpitations commonly occurring during treatment with nitrendipine are generally mild, usually subsiding with continued therapy. Thus, although additional long term studies are required to properly assess the relative merits of the drug compared with other antihypertensives, by providing the clinician with an effective and safe alternative to traditional therapies, nitrendipine represents a step forward in the treatment of mild to moderate hypertension.
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PMID:Nitrendipine. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic efficacy in the treatment of hypertension. 355 92

Reductions in left ventricular (LV) mass have been reported after antihypertensive therapy with certain sympatholytic agents and converting enzyme inhibitors, but little or no improvement has been noted after vasodilator therapy. In this study we evaluated the effect of the calcium channel blocker nitrendipine on echocardiographic LV mass. During a 12-month period, nitrendipine was used as monotherapy in 30 patients and in combination with propranolol or a diuretic in an additional 28 patients. Nitrendipine monotherapy lowered supine blood pressure from 148/97 to 136/83 mm Hg, but LV mass did not change significantly. Supine blood pressure decreased from 155/103 to 134/86 mm Hg in patients receiving combination therapy but, again, changes in LV mass were not significant. These data suggest that nitrendipine is effective in lowering blood pressure, but this is not associated with a significant decrease in LV mass in patients with mild hypertension.
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PMID:Effect of the calcium channel blocker nitrendipine on left ventricular mass in patients with hypertension. 378 Jan 30


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