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

Sixteen hydralazine-dependent hypertensive patients (7 females) were included in this clinical study. All patients were being treated with hydralazine, cyclopenthiazide and propranolol in the first visit to the laboratory. Two drugs were maintained during the study: the beta blocker and the diuretic. Hydralazine was discontinued and replaced by placebo during 3 weeks and after this period, verapamil was instituted at increasing doses. Replacing hydralazine by verapamil a better control of hypertension was obtained with a daily dose of 400 mg. The calcium entry blocker causes shortening of PEPc interval probably by reducing afterload which was only observed with the highest dose of verapamil (400 mg). ECG intervals were not modified by the different treatments with the exception of PR which was significantly increased by the major dose of verapamil. The calcium antagonist produced a stable reduction of blood pressure without affecting left ventricular function.
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PMID:Hypotensive action of verapamil in a group of hydralazine-dependent hypertensive patients. 683 86

Despite the beneficial therapeutic effects of antihypertensive drugs, some agents--particularly diuretics--seem to go in the "wrong direction" chemically. In fact, these changes could counteract some of the benefits resulting from lowering a patient's blood pressure. In the absence of hard evidence of the efficacy of long-term diuretic treatment of mild hypertension, we must be maximally sure that such therapy causes no harm. Thiazide and related diuretics have been associated with four distinct wrong-way chemical changes: increases in plasma concentrations of cholesterol, glucose, and uric acid, and a decrease in plasma potassium levels. The potential ramifications of such changes are well understood. The increase in circulating cholesterol, an established risk factor of myocardial infarction and stroke, is of particular concern--each year approximately one million hypertensive patients have myocardial infarctions. As a result, the search for safer and more effective diuretics must continue. Indapamide, a new antihypertensive drug, appears to meet these criteria. It is an effective diuretic with a considerable peripheral vasodilatory effect. Additionally, it does not appear to induce any significant change in circulating cholesterol, whereas chlorthalidone has been found to increase total cholesterol by 5%. Hydralazine is the only antihypertensive agent that seems to lower total cholesterol levels significantly. Neither indapamide nor hydralazine appears to affect plasma glucose levels; benzothiadiazines, however, have been found to induce an increase in circulating glucose.
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PMID:Some wrong-way chemical changes during antihypertensive treatment: comparison of indapamide and related agents. 686 7

Arterial hypertension that occurs after severe head injury is characterized by elevation of systolic blood pressure, tachycardia, increased cardiac output, normal or decreased peripheral vascular resistance, and increased circulating catecholamines. The effects of two drugs used in the management of hypertension, propranolol and hydralazine, on these indices of cardiovascular function were examined in six head-injured patients. Both drugs effectively normalized blood pressure. However, hydralazine increased heart rate by 30%, cardiac index by 49%, left cardiac work by 21%, and pulmonary venous admixture by 53%, and was responsible for an increase in intracranial pressure or decreased compliance in two patients. Hydralazine produced no consistent change in arterial catecholamines. In contrast, propranolol decreased heart rate by 21%, cardiac index by 26%, left cardiac work by 35%, pulmonary venous admixture by 15%, and oxygen consumption by 18%. Propranolol decreased arterial epinephrine levels by 48% and norepinephrine levels by 28%. Propranolol appears to be a useful antihypertensive drug in the hyperdynamic head-injured patient because it normalizes blood pressure and the underlying hemodynamic abnormalities both by its beta-adrenergic blocking action and by decreasing circulating levels of catecholamines.
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PMID:Treatment of hypertension associated with head injury. 688 59

Arterial blood pressure and pulse rate changes following tracheal intubation were studied in 20 patients undergoing intracranial surgery who received a thiopentone/suxamethonium anaesthetic induction sequence. Ten of the patients were pretreated with 0.4 mg/kg of hydrallazine and 10 with saline to determine whether hydrallazine prevents intubation hypertension. The results show that the incidence of intubation hypertension can be reduced using this dose of hydrallazine. Hydrallazine pretreatment is therefore recommended in patients at risk from hypertension following tracheal intubation.
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PMID:The prevention of hypertension at intubation. A controlled study of intravenous hydrallazine on patients undergoing intracranial surgery. 701 Oct 85

Hydralazine was administered acutely to 12 patients who had pulmonary arterial hypertension of unknown cause. All of the patients were studied at rest and nine during exercise. On the basis of hydralazine response at rest, the patients were divided in two groups. In six patients (group A), pulmonary arteriolar resistance (Rp) decreased from 8.4 +/- 1.4 to 4.8 +/- 1.4 U/m2 (p less than 0.001), cardiac index (CI) increased from 3.47 +/- 0.3 to 5.86 +/- 0.5 1/min/m2 (p less than 0.005) and systemic resistance (Rs) decreased from 25 +/- 4 to 14 +/- 2 U/m2 (p less than 0.01). The Rp/Rs ratio did not change significantly after hydralazine (0.32 +/- 0.03 vs 0.33 +/- 0.07, NS). In the other six patients (group B), Rs decreased from 25 +/- 2 to 17.0 +/- 1 U/m2 (p less than 0.01), but the other variables did not change significantly. Our results suggest that the pulmonary vasodilatory effect of hydralazine caused a marked reduction in right ventricular afterload in group A. In group B, a marked systemic vasodilatory effect occurred and right ventricular afterload was not reduced. On the basis of the previous hemodynamic response, only group A patients were treated with oral hydralazine (50 mg every 6 hours). Hemodynamic measurements were repeated 48 hours after hydralazine, both at rest and during exercise, as well as 8 months later in five of the six patients in whom the beneficial hemodynamic effects persisted. These data suggest that hydralazine can reduce Rp in selected patients (pulmonary arterial pressure less than 60 mm Hg, Rp less than 15 U/m2 and Rp/Rs ratio less than 0.7) with pulmonary hypertension of unknown cause.
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PMID:The role of hydralazine therapy for pulmonary arterial hypertension of unknown cause. 706 Feb 41

Three patients developed hepatic injury two months, ten months and two years, respectively, after hydralazine therapy for hypertension. Clinical and biochemical recovery followed discontinuation of drug therapy. Liver biopsies of the three patients revealed varying degrees of centrilobular necrosis. Complement 3 and Complement 4 levels were measured and found to be low in the patient with poor liver synthetic function, as was evident from the low serum albumin level and prolonged prothrombin time. Hydralazine-induced liver injury may be due to abnormality of drug metabolism in the liver.
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PMID:Hydralazine-induced hepatitis. 721 34

Chronic hydralazine treatment (2 weeks) in 22-week-old normotensive (WKY) and spontaneously hypertensive rats (SHR) significantly lowered the systolic blood pressure in both groups. Left ventricular papillary muscles from nontreated and treated WKY and SHR were placed in an isometric myography, and contractile indices monitored. Nontreated WKY and SHR were not statistically different comparing: tension, maximum contraction and relaxation rates, time to maximum tension, total contraction time, or passive and active length-tension curves. Hydralazine-treated WKY and SHR had significantly reduced tension and maximum rates of tension development and relaxation; passive length-tension characteristics were not altered. Stressing the papillary muscles with increased frequency of electrical stimulation (0.1-2 Hz) did not differentiate the various groups. Significant (p less than 0.05) alteration with isoproterenol (10(-9)-10(-5) M) occurred with the hydralazine-treated WKY, which responded with a greater increase in relaxation rate than the hydralazine-treated SHR. It is suggested that the clinically very useful drug, hydralazine, causes a distinct contractile state alteration in rat myocardium after treatment sufficient to lower SHR blood pressure to a normal range.
Hypertension
PMID:Hydralazine: effect on contraction mechanics of WKY and SHR rat heart muscle. 725 Oct 97

A combination of propranolol and hydrallazine was administered to 13 patients with longstanding hypertension during 15 pregnancies. Hydrallazine was continued through labour and delivery in all patients, while in eight patients propranolol was discontinued 2 to 15 days before delivery. Blood pressure control was uniformly good and superimposed pre-eclampsia did not occur during combined therapy. There were 14 livebirths and one unexplained stillbirth. Except for two cases of milk hypoglycemia, there were no neonatal complications.
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PMID:Propranolol and hydrallazine in the management of essential hypertension in pregnancy. 736 97

Blood pressure changes following carotid endarterectomy were studied in 39 patients undergoing 42 carotid endarterectomies, in order to establish the incidence of hypertension and to study the use of hydrallazine for its treatment. Hypertension occurred in 28 cases (66%) and was treated with intravenous hydralazine in a dose of 20 +/- 8 mg; this resulted in a systolic blood pressure fall of 46 +/- 22 mmHg, diastolic blood pressure fall of 24 +/- 12 mmHg, mean blood pressure fall of 31 +/- 15 mmHg, and a pulse rate increase of 7 +/- 9 beats per minute. Hydrallazine is a safe, effective drug for the treatment of intraoperative hypertension.
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PMID:Post carotid endarterectomy hypertension. 739 84

Previous studies showed that aortic strips from rats with either spontaneous (SHR) or DOCA/salt-induced hypertension developed less stress (force/area) in response to noradrenaline (NA) when compared to aortic strips from normotensive rats. Portal vein strips from SHR, but not from DOCA/salt hypertensive rats, developed greater force to NA compared to strips from control rats. We have investigated whether these changes are prevented by hydralazine. Hydralazine was added to the drinking solution (1% NAC1) of one group of rats from the first day of treatment with DOCA. In the second group, hydralazine was added to the drinking water of 13-week-old SHR. After 3 weeks of treatment with hydralazine, cumulative dose-response relationships to NA were studied using aortic and portal vein strips from hydralazine-treated and control rats. Hydralazine prevented the increase of arterial pressure and the decrease of stress developed to NA by the aortic strips from both SHR and DOCA/salt rats. It did not prevent the increase of force developed to NA by the portal vein strips from SHR. Thus, reduced contractile response of the aortic strips from hypertensive rats seems to be the result of a high pressure, since both the rise in blood pressure and reduced aortic response are prevented by hydralazine. Increased contratile response of the portal vein strips from SHR appears to be independent of blood pressure.
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PMID:Hydralazine prevents changes in the contractile response of aortic but not portal vein strips in hypertensive rats. 743 22


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