Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ketanserin is a serotonin antagonist with high affinity for S2-serotonergic receptors, which mediate the vasoconstrictor effects of serotonin. It does not block the vasodilator effects of this monoamine, and it is devoid of agonist activity and serious central side effects. Ketanserin, however, also binds to alpha 1-adrenoceptors. The compound (10 mg i.v.) was given to 30 patients with essential hypertension and four normotensive patients with chronic autonomic failure, owing to an efferent sympathetic lesion. Ketanserin lowered systolic and diastolic arterial pressure by about 20%. The effects on cardiac output, cardiac filling pressures, forearm blood flow, renal blood flow, and glomerular filtration rate revealed a hemodynamic pattern compatible with dilatation of both resistance and capacitance vessels. These vasodilator effects were accompanied by moderate reflex stimulation of the heart. The drug did not alter the pressor effect of bolus injections of the alpha 1-adrenoceptor agonist phenylephrine, which contrasted with the competitive antagonism exerted by the alpha 1-adrenoceptor antagonist prazosin. Baroreflex-mediated bradycardia after phenylephrine also was not affected by ketanserin. The drug had a distinct hypotensive effect in patients with autonomic failure, despite the fact that these patients did not respond to the nonselective alpha-adrenoceptor antagonist phentolamine, 20 mg i.v. Thus, ketanserin is capable of lowering arterial pressure independently of alpha 1-adrenoceptor blockade. The results are therefore indirect evidence supporting a role of serotonin in hypertension.
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PMID:Ketanserin: a possible tool for studying the role of serotonin in hypertension. 241 35

Ketanserin is a 5-HT2 antagonist with alpha-adrenoreceptor blocking activity. This study examines the efficacy and safety of ketanserin in the control of severe primary and secondary hypertension, including renal hypertension. Patients with uncontrolled hypertension were admitted to hospital and entered the study if the supine diastolic blood pressure phase V (SDBP) was greater than 110 mm Hg after 2 h continuous BP monitoring (Dynamap). Ketanserin was administered as an intravenous (i.v.) 5 mg bolus every 60 s until SDBP fell greater than 15 mm Hg or maximum dose (30 mg) was reached, then by i.v. infusion at 4-20 mg/h to maintain SDBP fall greater than 15 mm Hg over 6 h. Twenty five patients were monitored and 20 (seven men, 13 women, ages 14-65 years) fulfilled the entry criteria. Seventeen of 20 were on antihypertensive medication, and 14 had underlying renal disease. Preinjection mean BP was 188/123 mm Hg for the 20 patients, falling at 5 min to 175/103 mm Hg. Supine diastolic blood pressure fell greater than 15 mm Hg in 16 of 20 patients. In these patients, BP remained satisfactorily controlled over the 6-h ketanserin infusion. Heart rate was unchanged. The four patients who did not respond were receiving the alpha-blocker prazosin, but seven other patients on high-dose prazosin did respond. We conclude that i.v. ketanserin is effective in the acute management of severe hypertension, including hypertension secondary to renal disease.
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PMID:Ketanserin in the acute management of severe hypertension. 241 44

Ketanserin, a new selective 5-HT2-serotonergic antagonist, was used to: confirm its hypotensive efficacy in acute and long-term treatment, determine its influence on the influence on the metabolism of serotonin (5-HT) and catecholamines, and elucidate their mutual relationship. Ketanserin was given intravenously to 10 patients with hypertensive crisis or resistant hypertension and orally to 15 patients with mild to severe hypertension for 1 year. Blood pressure, heart rate, 24-h urinary excretion of vanilmandelic acid (VMA; the major endproduct of catecholamines) and of 5-hydroxyindoleacetic acid (HIAA; the endproduct of serotonin metabolism), and platelet aggregation were measured. In doses normalizing blood pressure and platelet aggregation, ketanserin administered to hypertensive patients either intravenously in acute treatment or orally in chronic treatment caused: (a) decreased HIAA excretion (more marked in chronic than in acute treatment) and (b) simultaneous decrease in VMA excretion. It is concluded that the decisive sites of ketanserin action are the 5-HT2 receptors of platelets. The compound reduces platelet aggregation and the release of 5-HT, its metabolism, and, hence, the excretion of HIAA. The action of ketanserin on 5-HT2 receptors of vascular smooth muscle participates in the hypotensive effect of the drug but does not explain the decreased excretion of HIAA and VMA.
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PMID:Blood pressure, 5-OH indoleacetic acid, and vanilmandelic acid excretion and blood platelet aggregation in hypertensive patients treated with ketanserin. 241 52

The effects of serotonin and its pharmacological antagonists on the physical flow properties of the blood have been studied far less than their effects on blood vessels, although they may be equally important. Indirect evidence suggests that in pathological circumstances serotonin may locally increase whole blood viscosity, particularly at low shear rates, decrease red cell deformability and increase the adhesiveness of white cells. Although the viscosity of the plasma alone is not affected, the rheological effects of serotonin on blood cells is probably dependent on the presence of platelets. These mechanisms may have a systemic effect in some forms of hypertension as well as in situations of local ischaemia such as Raynaud's phenomenon, atherosclerotic pregangrene of the leg or acute myocardial infarction. Specific serotonergic-antagonists, administered either orally or intravenously, normalize the increased whole blood viscosity and decreased blood filterability found in essential hypertension, following myocardial infarction and in severe leg ischaemia. The effect on red cell deformability is usually greatest when the cells are resuspended in platelet rich plasma. Ketanserin given intravenously for seven days to patients with very severe leg ischaemia, significantly improves whole blood viscosity, increases red cell transit time and most dramatically decreases pore clogging. This last effect was at least partly due to a change in the physical properties, but not the number of the white cells. The reported beneficial clinical effects of such an antagonist in various forms of peripheral ischaemia and essential hypertension may well be due, at least partly, to the normalization of the rheological properties of the blood.
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PMID:Serotonin and the flow properties of blood. 241 54

The cardiovascular effects of ketanserin (5-HT2-receptor antagonist with alpha 1-receptor blocking property) were studied during coronary artery surgery. Sixteen patients were anesthetized with flunitrazepamfentanyl-nitrous oxide-oxygen-pancuronium. Ketanserin (10 mg i.v.) was used to decrease elevated blood pressure unresponsive to deepening of anesthesia before extracorporeal circulation. Ketanserin caused a marked vasodilation in all patients, significant (p less than 0.05) decreases of systolic, diastolic, and mean arterial blood pressure, and of pulmonary artery pressure and pulmonary capillary wedge pressure. As a result, indirect indices of myocardial oxygen demand (rate-pressure product and "triple index") also decreased. Heart rate and right atrial pressure remained unchanged, while cardiac index and stroke volume index increased slightly. Ketanserin was found to be effective in the treatment of prebypass hypertension; the elevated blood pressure returned to normal; unwanted hypotension was not observed.
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PMID:Cardiovascular effects of ketanserin in the treatment of hypertension during coronary artery bypass surgery. 241 72

A 65-year-old man with arterial hypertension received oral treatment with Ketanserin, a new drug, during a period of five months. He developed marked QT interval prolongation and have several Stokes-Adams attacks. A Holter recording obtained during one of these episodes showed torsade de pointes ventricular tachycardia. The arrhythmias occurred during maximum QT interval prolongation. The correlation between Ketanserin and QT interval prolongation was evaluated by using several Holter studies during administration and withdrawal of the drug. The effect of Ketanserin on the QTc interval was analyzed retrospectively in six patients who had been taking the drug orally. Following a period of four to eight months, the QTc interval was prolonged by the drug (5 to 31%, mean 17%) in five patients. We conclude that torsade de pointes is a potential hazard of long-term treatment with Ketanserin.
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PMID:QT prolongation and torsade de pointes ventricular tachycardia produced by Ketanserin. 243 86

Ketanserin, the specific S2 serotonin antagonist, is undergoing evaluation for the therapy of hypertension of all degrees of severity. We studied 20 patients with severe hypertension [diastolic blood pressure (DBP) greater than 120 mm Hg after 40 min of supine rest]. In the first dose-ranging study on eight patients, multiple i.v. injections of 5 mg ketanserin were administered every 4 min (mean 38 mg). Only 4 patients responded adequately (DBP less than 100 mm Hg), 2 responded partially, and 2 did not respond to ketanserin. The major adverse effect of ketanserin, found in all patients, was severe dose-dependent sleepiness. A second double-blind crossover study with ketanserin and placebo (12 patients) assessed neural side effects. The supine DBP dropped from a mean of 134 +/- 4 mm Hg to 112 +/- 4 mm Hg 20 min after ketanserin when the sedation score rose from 0 to 1.2 +/- 0.3 (range 1-3) and the dizziness score from 0.1 +/- 0.1 to 1.4 +/- 0.3 (range 1-3; both p less than 0.01 vs. 1-2 min after ketanserin). Only 7 of 12 patients responded adequately to ketanserin. Twelve of the 20 patients were subsequently given nifedipine 10 mg sublingually; the DBP fell from a mean of 128 +/- 3 mm Hg to 101 +/- 4 mm Hg (p less than 0.001) after 40 min without side effects. Ketanserin does not appear to be a suitable agent for the acute therapy of severe hypertension because of: the imperfect and short-lived blood pressure control; the variability of the hypotensive effect; and sleepiness and dizziness as significant side effects.
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PMID:Effects of intravenous ketanserin on severely hypertensive patients with double-blind crossover assessment of central side-effects. 243 87

The serotonergic antagonist ketanserin (K) was compared to nifedipine (N) in a five-center international study on hypertensive patients over the age of 50 years. After a 4-week placebo run-in period, patients were randomly assigned to receive for 3 months either ketanserin (40 mg b.i.d. after 2 weeks of 20 mg b.i.d.) or nifedipine (20 mg N retard b.i.d.). After 1 month, monotherapy patients whose blood pressure was not sufficiently reduced received a diuretic in combination therapy. At the end of the active treatment period, patients who had remained on monotherapy received placebo until hypertension returned or for a maximum of 2 months. One hundred and seventeen patients were entered in the study, 58 on K and 59 on N. More patients switched to combination with a diuretic in the K group (14 patients) than in the N group (6 patients). The overall reduction in blood pressure was similar for K and N. Total response rate was high (96%) for the two drugs. Blood pressure was reduced both at peak and trough drug levels. No orthostatic reactions were observed, and no rebound hypertension occurred at discontinuation of therapy. Ketanserin monotherapy slightly decreased heart rate (-1 beats/min). whereas N produced a significant increase (+6 beats/min). Body weight significantly increased with K (+1.1 kg) and was unchanged with N. More patients complained of adverse reactions during N monotherapy (47%) than during K monotherapy (34%). Flushing and leg edema were more frequent with N.
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PMID:Ketanserin versus nifedipine in the treatment of essential hypertension in patients over 50 years old: an international multicenter study. 244 56

Ketanserin is a novel agent that has been shown to be a specific 5-HT2-serotonergic antagonist. It has useful antihypertensive properties. Owing to its unique mechanism of action, it has been suggested that ketanserin may have a favorable effect on tissue blood flow during chronic therapy for hypertension. This double-blind study was designed to evaluate the acute (1 week) and chronic (8 weeks) effects of ketanserin on renal hemodynamic parameters and renin-aldosterone axis in patients with uncomplicated hypertension. Compared to placebo, ketanserin caused a significant blood pressure reduction at the end of the 8-week study period. Despite the reduction in systematic arterial pressure, glomerular filtration rate and renal plasma flow were preserved. Ketanserin therapy induced a slight reduction in plasma renin activity and a marginal increase in the sodium excretion. Although the results of this study are limited by the small number of patients, it appears that ketanserin may have favorable renal hemodynamic effects in uncomplicated essential hypertension.
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PMID:Renal hemodynamic effects of ketanserin therapy in essential hypertension. 244 78

Ketanserin, a serotonin-2-receptor antagonist, was administered to 12 subjects with mild to moderate hypertension in a randomized, double-blind, placebo-controlled crossover trial. After 6 weeks of ketanserin (40 mg every 12 h), blood pressures measured 12 h after dosing were not significantly different from those obtained during the placebo period. However, 2 h after ketanserin administration, supine systolic and diastolic blood pressures declined 11 +/- 10 mm Hg (p less than 0.01) and 6 +/- 5 mm Hg (p less than 0.005) from predose values, whereas placebo caused no change in either systolic or diastolic blood pressure. At the time of peak antihypertensive activity, plasma renin activity, aldosterone, growth hormone, and prolactin levels were unchanged. Prolactin levels decreased slightly (4.1 +/- 3.0 vs. 3.7 +/- 2.9 ng/ml, p less than 0.05) during ketanserin therapy when measured 12 h after dosing. Other pituitary hormones, serum testosterone, plasma catecholamines, and plasma lipids showed no changes. Heart rate was also unchanged. Stroke volume, measured 2 h after dosing, increased (70 +/- 22 vs. 85 +/- 31 ml, p less than 0.05) with ketanserin therapy, but cardiac output did not change significantly. Ketanserin has a moderate antihypertensive effect and neutral metabolic-hormonal profile when used as monotherapy for the treatment of hypertension. However, further studies are needed to define the frequency of dosing that will provide 24-h antihypertensive activity.
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PMID:Antihypertensive therapy with ketanserin: metabolic and hemodynamic effects. 246 37


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