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

Nifedipine, in a slow release preparation, was given at a mean daily dosage of 47 +/- 4 mg to 12 patients with severe hypertension in whom arterial pressure was not satisfactorily controlled (mean arterial pressure 132 +/- 4 4 mm Hg) by the combination of a converting enzyme inhibitor and a diuretic. The addition of nifedipine induced an appreciable decrease in mean arterial pressure of 31 +/- 5 mm Hg and of serum potassium and plasma aldosterone. After adequate control of hypertension and because of severe hypokalemia in some patients, discontinuation of the diuretic was attempted in 10 subjects. After 1.7 +/- 0.5 months of treatment by the converting enzyme inhibitor and nifedipine no change in arterial pressure occurred while serum potassium had returned to normal in most patients. These results show that nifedipine may be useful in patients with a residual rise of arterial pressure when treated by converting enzyme inhibitor plus diuretics; in such patients, however, the serum potassium concentration should be carefully monitored. In addition, our observations suggest that calcium blockers may be an effective alternative to diuretics in patients receiving a converting enzyme inhibitor.
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PMID:Effect of chronic nifedipine in patients inadequately controlled by a converting enzyme inhibitor and a diuretic. 258 Jan 84

We conducted a randomised double-blind crossover comparison of felodipine, 10 mg once daily, nifedipine 20 mg twice daily, each treatment being given as a monotherapy for four weeks. Active treatment was preceded by a two-week placebo run-in. Both systolic (SBP) and diastolic (DBP) blood pressures (supine and erect) fell significantly (all P less than 0.001) following both drug treatments. Nifedipine produced a greater orthostatic effect, and hence a significantly greater fall in erect SBP than felodipine (P less than 0.05). There was no significant difference between the effects of the drugs on DBP. Achieved DBP was 90 mmHg or less in 18/22 patients on felodipine and 18/22 patients on nifedipine. Both drugs were well-tolerated. Felodipine given once daily was effective as a monotherapy for the control of mild to moderate hypertension and compared favourably with twice daily nifedipine.
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PMID:A comparison of felodipine and nifedipine as monotherapies for the treatment of mild to moderate hypertension. 265 58

In 12 severe (diastolic values averaging 114 mmHg) hypertensives with unilateral renal artery stenosis (angiography) and hyperreninemia, we investigated the acute effects of nifedipine (10 mg orally) on renin and systemic hemodynamics. Plasma renin activity was determined on blood samples withdrawn from the aorta and both renal veins, so that "ischemic lateralization" could be evaluated through appropriated derived indexes. Nifedipine promptly and significantly lowered the aortic pressure in all patients. At 30 min maximal circulatory responses were recorded, which consisted of 22% decrease in mean aortic pressure (from an average of 144.6 +/- 15 to an average of 113 +/- 11 mm Hg), 44% reduction of systemic vascular resistance (from 2162 +/- 540 to 1205 +/- 279 dynes.S.cm-5), 33% rise of cardiac index (from 2920 +/- 970 to 3875 +/- 986 ml/min/m2). These effects were still evident, although somewhat tempered, after 180 min continuous monitoring; they were qualitatively and quantitatively similar to those reported by some authors in primary hypertensives with similar levels of blood pressure. After nifedipine, renin activity of the systemic blood significantly rose, due to a potentiated release from the kidney with arterial stenosis. This effect, that was interfered as a due to further reduction of the renal perfusion pressure, improved the significance of "ischemic lateralization" indexes and supported the diagnosis of renovascular hypertension in all of cases. It is suggested that nifedipine may not only be regarded as an additional diagnostic tool, but also as an effective antihypertensive agent in this disorder, al least in the short term. This contrasts with the previous suggestion of nifedipine as substantially more effective in low-renin rather than high-renin hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Circulatory and renin response to the administration of nifedipine in renovascular hypertension]. 269 Oct 77

There has been increasing interest in the use of calcium antagonists as arterial vasodilator agents in the management of patients with congestive heart failure. Because congestive heart failure is mostly secondary to coronary artery disease, calcium antagonist drugs seem particularly appealing because of their anti-ischemic properties. The potent vasodilating action of calcium antagonists decreases impedance and improves ejection phase indexes of left ventricle function. However, these drugs interfere with calcium availability for myocardial contraction, and concern has been expressed about their potential depressant effect on myocardial performance. The net hemodynamic effect depends on the relative vascular versus myocardial potency of each calcium antagonist and on the indirect effects of reflex sympathetic activation. Balance between these factors is still influenced by the intrinsic status of left ventricle of the patient. Generally, the negative inotropic direct effect of the calcium antagonists is counteracted by the beneficial influence of the decrease of systemic vascular resistance. Because of its relatively more pronounced negative inotropic action, verapamil is not advisable in patients with left ventricular failure. Limited experience with diltiazem show no significant negative inotropic action. Nifedipine has been studied in its acute and long term effects. The use of sublingual nifedipine is established in the emergency management of acute pulmonary edema, specially in patients with arterial hypertension, or when acute ventricular dysfunction is associated with mitral or aortic insufficiency. Patients with chronic congestive heart failure have shown after nifedipine an increase in stroke volume and cardiac index at rest and during exercise, as well as decreases of pulmonary capillary wedge pressure during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Role of calcium antagonists in the pharmacologic treatment of heart insufficiency]. 269 18

Nifedipine treatment resulted in variable improvement in tardive dyskinesia in eight geriatric psychiatric patients. Patients with affective disorders and hypertension demonstrated improvement in other areas as well.
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PMID:Calcium channel blockers for tardive dyskinesia in geriatric psychiatric patients. 276 82

The effect of nifedipine (Adalat; Bayer-Miles)--a calcium channel blocker, which has a well-established place in nonobstetric hypertension--was compared with dihydralazine in 33 primigravidas with severe hypertension of pregnancy. Patients with a diastolic blood pressure greater than 110 mmHg before drug administration were randomly assigned to treatment with either nifedipine or dihydralazine. Both drugs were found to be equally efficacious. Nifedipine, however, showed an earlier onset of action in lowering systolic blood pressure and had the advantage of oral administration.
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PMID:Nifedipine in acute hypertensive emergencies in pregnancy. 278 21

As the number of antihypertensive agents increases, the choice of optimal therapy becomes more difficult. Certainly, hemodynamic derangements caused by the disease state as well as therapy must be considered. Patient convenience and quality of life are also issues that must be addressed. Preliminary experience suggests that the gastrointestinal therapeutic system (GITS) push-pull osmotic pump formulation of nifedipine is safe and efficacious in the treatment of hypertension. In 1 study, nifedipine GITS was compared with sustained-release propranolol in patients with mild to moderate hypertension already receiving diuretics. Using a 2-week placebo run-in, double-blind study design, patients were randomly assigned to receive nifedipine GITS (n = 31) in doses of 30, 60 or 90 mg once daily, or sustained-release propranolol (n = 32) in doses of 80, 160 or 240 mg once daily. Previous diuretic therapy was continued. Sitting and 5-minute standing blood pressure and heart rate measurements were obtained 24 hours after dosing. At the end point of treatment, both nifedipine GITS and sustained-release propranolol reduced blood pressure compared with placebo (p less than 0.001) in the sitting and standing positions. Nifedipine GITS was more effective than sustained-release propranolol in reducing standing (p less than 0.005) and sitting (p less than 0.001) systolic blood pressure and sitting diastolic blood pressure (p less than 0.02). Sustained-release propranolol caused a greater reduction in standing (p less than 0.001) and sitting (p less than 0.0006) resting heart rate than nifedipine GITS. Both drugs were well tolerated.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The nifedipine gastrointestinal therapeutic system in the treatment of hypertension. 278 73

m-Nifedipine (m-Nif) had weaker inhibitory effects than nifedipine (Nif) on the staircase phenomenon, functional refractory period and contraction (IC50: m-Nif/Nif = 18) of isolated guinea pig left atria at concentrations of 0.1-1.0 mumol/L. At the same concentrations, both m-Nif and Nif could hardly change the post-rest potentiation, excitability and ectopic automaticity induced by epinephrine. m-Nif 0.05 mumol/L, had no effect on the automatic contractile force of isolated right atria but could slow down the automatic rhythm. On the contrary, Nif had little effect on the automatic rhythm but potently inhibited the contractile force. Furthermore, in isolated rabbit aorta strips, m-Nif had an equal or somewhat stronger inhibitory effect on the tension induced by KCl. These results suggest that m-Nif might be superior to Nif in treating myocardial ischemia, arterial hypertension and congestive heart failure.
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PMID:[Comparison of actions of m-nifedipine and nifedipine on isolated guinea pig atria and rabbit aortic strips]. 281 3

This study was designed to assess whether the acute blood pressure response of an individual hypertensive patient to a calcium antagonist or an angiotensin converting enzyme (ACE) inhibitor is a good predictor of the long-term efficacy of these drug classes in this particular patient. The concept that good responses to ACE inhibitors and calcium antagonists may be mutually exclusive was also tested. Sixteen patients were included in a randomized crossover trial of enalapril, 20 mg daily, and diltiazem, 120 mg daily, for 6 weeks each. Blood pressure was measured by ambulatory blood pressure recording. During the washout phase, the acute effect of nifedipine, 10 mg p.o., and enalaprilat, 5 mg i.v., was evaluated. Nifedipine and enalaprilat reduced blood pressure equally well. The long-term blood pressure reduction induced by enalapril and diltiazem was similar. The acute blood pressure response to a given drug was not a good predictor of the result obtained with long-term therapy. No age dependency of the antihypertensive effect of either drug class was apparent. There was no evidence that a good response to one drug excluded a similarly good response to the other.
Hypertension 1988 Feb
PMID:Individual responses to converting enzyme inhibitors and calcium antagonists. 283 Jan 89

In nine young normotensive subjects with no family history of hypertension and nine age-matched normotensive subjects with one parent with essential hypertension, effective renal plasma flow (p-aminohippuric acid clearance), glomerular filtration rate (inulin clearance), and excretion of sodium and exogenously administered lithium were measured for 90 minutes before and after administration of a single 20-mg oral dose of the calcium entry blocker nifedipine. Segmental tubular handling of fluid and sodium was estimated using lithium clearance as a marker of proximal tubular reabsorption. Nifedipine did not cause any change in subjects with no family history of hypertension, but in those with one hypertensive parent there was a marked increase in effective renal plasma flow (from 644 +/- 39 to 847 +/- 42 [SEM] ml/min x 1.73 m2; p less than 0.001) and a decrease in filtration fraction (from 17.6 +/- 1.0 to 12.6 +/- 0.4%; p less than 0.001), while the glomerular filtration rate was unchanged, thus suggesting a prevailing efferent vasodilation. Sodium excretion rate (p less than 0.02) and fractional sodium excretion (p less than 0.025) increased slightly but significantly in subjects with one hypertensive parent, but not in normotensive subjects with no family history of hypertension. Lithium clearance also rose (from 29.0 +/- 2.0 to 32.8 +/- 1.9 ml/min, p less than 0.001), and the derived value of fractional proximal reabsorption diminished (from 75.8 +/- 1.0 to 71.3 +/- 1.2%, p less than 0.001). Estimated distal delivery of sodium and absolute distal sodium reabsorption both increased significantly (p less than 0.005), while fractional distal sodium reabsorption was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)
Hypertension 1988 Nov
PMID:Abnormal renal responses to calcium entry blockade in normotensive offspring of hypertensive parents. 284 83


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