Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0012833 (dizziness)
 9,689 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Prizidilol (SKF 92657), a new antihypertensive drug with combined precapillary vasodilator and non-selective beta-adrenoceptor-blocking actions, was given to 24 patients with essential hypertension in a placebo-controlled, dose-titration study, Incremental doses from 200 to 800 mg were given once daily. Supine and standing blood pressure measured 24--27 h after drug intake was reduced during treatment with prizidilol (400--800 mg/day). Slight but significant decreases in heart rate were seen after moderate doses (mean: 447 mg once daily) of prizidilol. A more pronounced blood pressure reduction was noticed 2--7 h after drug administration. 2. Maximal blood pressure reduction coincided with peak plasma concentration of prizidilol, which was measured by a newly developed assay. 3. Plasma renin activity and 24 h urinary excretion of aldosterone and methoxycatecholamines were reduced after the highest doses (mean: 700 mg once daily) of prizidilol. 4. Prizidilol was well tolerated, although dizziness and tiredness were reported by four patients and oedema by two.
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PMID:Prizidilol (SKF 92657) in primary hypertension. 718 85

A tilt-table test was administered to five young men before (test 1) and after (test 2) 8 days of heat acclimation (2-h daily exercise at 50% VO2max at 40 degrees db, 30 degrees C wb) and to five other young men before and after the same exercise at 24 degrees C to determine fluid-electrolyte and endocrine responses in orthostasis in fainters and nonfainters. Half of the 10 subjects showed improved orthostatic reactions from test 1 to test 2 (disappearance of nausea and dizziness and improved heart rate and blood pressure), and the other 5 subjects showed no improvement. The improvement, especially in the nonfainters, was related to increases in posttilt plasma volume (PV) and plasma concentration of potassium. During test 1, plasma renin activity (PRA) increased five times from supine to orthostatis, with a corresponding increase in plasma vasopressin (ADH) of 50 times. The corresponding increases in test 2 were lower by 50 and 75% compared with those occurring in test 1 for PRA and ADH, respectively. PRA was five times higher in nonfainters than in fainters in test 1, whereas ADH showed an opposite trend. The orthostatic-induced increase in ADH seems to be related to volume control independent of PRA. This increase is reduced with improvement in orthostatic reactions, probably because of an increase in PV.
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PMID:Orthostatic fluid-electrolyte and endocrine responses in fainters and nonfainters. 731 73

We compared the response of the oral angiotensin II (Ang II) receptor antagonist (ARA) UP 269-6 with an angiotensin converting enzyme inhibitor (ACEI) enalapril 20 mg or placebo, during salt depletion in normal men. We also evaluated safety and tolerability. Sixteen healthy, normotensive male volunteers followed a standardised salt-depletion regimen for 3 days before each study day. Seven different doses of UP 269-6 (5, 10, 20, 40, 80, 120 and 180 mg) were administered double blind in a four-panel dose escalation, with enalapril and placebo randomised within each panel. Supine and erect blood pressure (BP) and heart rate (HR); serum and urinary electrolytes; plasma active renin (PAR), aldosterone, and Ang II were measured at intervals. Urinary electrolytes and aldosterone were measured for the 24 h before dosing and for 24 h after dosing. Dizziness and light-headedness on standing were reported after UP 269-6 at higher doses. Enalapril caused one episode of symptomatic postural hypotension. No other drug-related adverse events (AE) were noted. There was a dose-related decrease in supine and erect systolic and diastolic BP (SBP, DBP) with UP 269-6 at > or = 40 mg, with no change in HR. Based on the maximal decrease in mean arterial pressure (MAP), UP 269-6 at 180 mg had an effect largely comparable to that of enalapril 20 mg. There was a dose-related increase in PAR with UP 269-6. Although this was greater with UP 269-6 180 mg than with enalapril, serum and 24-h urinary aldosterone suppression was greater with enalapril than with any dose of UP 269-6.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Comparison of the oral angiotensin II receptor antagonist UP 269-6 or enalapril 20 mg on blood pressure and neurohormonal effects in salt-deplete man. 756 47

The effect of carmoxirole, a presynaptic dopamine (DA2) receptor agonist, on blood pressure, plasma catecholamines, renin-aldosterone and atrial natriuretic peptide and the intracellular concentration and transmembrane fluxes of Na+ and K+, in erythrocytes and platelets was studied in 24 normal men, using a double-blind, parallel study design. After a run-in period of 1 week, the subjects were treated with either placebo (n = 8) or 0.5 mg carmoxirole (n = 16) once daily for 1 week. Blood pressure and heart rate were not changed during carmoxirole administration in these normal men. Surprisingly, no significant effect of carmoxirole was found on the circulating plasma concentration of noradrenaline, adrenaline or dopamine. Other hormones such as renin, aldosterone and atrial natriuretic peptide were also not changed during carmoxirole administration. No significant effect of carmoxirole could be demonstrated on the intracellular concentration of Na+, K+, Mg2+ and Ca2+ and on the transmembrane fluxes of Na+ and K+ in erythrocytes and platelets. In the carmoxirole-treated subjects (n = 16), 6 subjects reported spontaneously adverse events such as syncope, dizziness and vomiting tendencies and/or fatigue.
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PMID:Erythrocyte and platelet cationic concentrations and transport systems in normal volunteers treated with carmoxirole. 790 90

The pharmacokinetics and pharmacodynamics of the ACE inhibitor quinaprilat have been studied in six chronic haemodialysis (HD) patients and in six patients undergoing continuous ambulatory peritoneal dialysis (CAPD) after a single oral dose of 2.5 mg quinapril. Mean tmax and Cmax values (SEM) for quinaprilat in interdialytic HD patients were 4.0 (0) h and 84 (8.4) ng.ml-1 respectively, and they did not differ significantly from those in CAPD patients (4.7 (0.7) h and 64 (5.7) ng.ml-1). Elimination half lives were 30 (10.1) h (HD) and 34 (7.3) h (CAPD). Cmax, tmax, t1/2, and AUC were increased and CL was decreased compared to data reported previously after giving 2.5 mg to healthy subjects. Peritoneal clearance was calculated as 0.1 (0.1) ml.min-1, thus less than 0.5% of the dose were removed within 24 h by CAPD. ACE activity was suppressed by more than 93% between 4 and 24 h postdose (P < 0.001). It decreased in both groups with increasing plasma quinaprilat levels. Angiotensin II concentration compared to baseline was significantly decreased at 4 hours (-30.4 +/- 10%) and 24 h (-30 +/- 9.9%) (P < 0.05, n = 11), while active plasma renin concentration was still significantly increased at 48 h postdose (+ 60.2 +/- 14.5%, P < 0.01). Mean arterial pressure 24 h postdose was significantly (P < 0.05) decreased in HD (-12 mmHg) and CAPD patients (-20 mm Hg). Only two patients reported unwanted effects (fatigue, dizziness, nausea, and weakness). In conclusion, due to its long lasting effect on ACE activity and on blood pressure in terminal renal failure a starting dose of quinapril 2.5 mg o.d. may be used in hypertensive HD and CAPD patients.
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PMID:Pharmacokinetics and pharmacodynamics of quinaprilat after low dose quinapril in patients with terminal renal failure. 838 27

The study was designed to assess the antihypertensive effect of combined angiotensin-converting enzyme (ACE) inhibition and angiotensin II type 1 receptor (AT1) antagonism in patients with essential hypertension. Twenty patients with uncontrolled ambulatory diastolic blood pressure (BP) after 6 weeks of ACE inhibitor monotherapy (benazepril, 20 mg, o.d.) were randomized to receive double-blind valsartan, 80 mg, o.d. (AT1 antagonist) or matching placebo for 5 weeks while continuing to receive background benazepril. Then patients crossed over to the alternative regimen for a second 5-week period. The 24-h ambulatory BP was monitored on the final day of the benazepril monotherapy period and on the final day of each double-blind treatment period. Valsartan added to benazepril produced a significant antihypertensive effect with a benefit over placebo of 6.5 +/- 12.6/4.5 +/- 8.0 mm Hg (systolic/diastolic) for average awake ambulatory BP (p < 0.05), 7.1 +/- 9.4/5.6 +/- 6.5 mm Hg for asleep BP (p < 0.01), and 6.8 +/- 9.7/4.9 +/- 6.8 mm Hg for average 24-h ambulatory BP (p < 0.01). Pulse rate was unaffected. Plasma active renin was higher on the benazepril-valsartan combination compared with benazepril-placebo (p < 0.05). There was no change in routine biochemical variables when valsartan was added to benazepril. Six patients reported mild dizziness or fatigue (three also with placebo). These data suggest that in hypertensive patients uncontrolled with an ACE inhibitor, the addition of an AT1 antagonist provides a powerful and safe antihypertensive drug combination.
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PMID:Additive hypotensive effect of angiotensin-converting enzyme inhibition and angiotensin-receptor antagonism in essential hypertension. 1083 30

Angiotensin II (AT-II)-receptor antagonists are reviewed. Research focused on blocking the renin-angiotensin system (RAS) led to the discovery of angiotensin-converting-enzyme (ACE) inhibitors, which are effective in the treatment of hypertension but are associated with a high frequency of cough and other adverse effects. AT-II-receptor antagonists were developed as agents that would more completely block the RAS and thus decrease the adverse effects seen with ACE inhibitors. AT-II-receptor antagonists include losartan, valsartan, irbesartan, candesartan, eprosartan, telmisartan, and tasosartan. Several clinical trials have demonstrated that AT-II-receptor antagonists are as effective as calcium-channel blockers, beta-blockers, and ACE inhibitors in the treatment of hypertension and induce fewer adverse effects. The adverse effects of AT-II-receptor antagonists--dizziness, headache, upper-respiratory-tract infection, cough, and gastrointestinal disturbances--occur at about the same rate as with placebo. [corrected]. All available AT-II-receptor antagonists seem to be equally effective in reducing both systolic and diastolic blood pressure, and they are comparable in cost. Currently, AT-II-receptor antagonists are used either as monotherapy in patients who cannot tolerate ACE inhibitors or in combination with other antihypertensive agents. Angiotensin II-receptor antagonists are well tolerated and are as effective as ACE inhibitors in decreasing blood pressure.
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PMID:Angiotensin II-receptor antagonists: an overview. 1090 66

We report the case of a 72-year-old female with pure autonomic failure, a rare entity, whose diagnosis of autonomic dysfunction was determined with a series of complementary tests. For approximately 2 years, the patient has been experiencing dizziness and a tendency to fall, a significant weight loss, generalized weakness, dysphagia, intestinal constipation, blurred vision, dry mouth, and changes in her voice. She underwent clinical assessment and laboratory tests (biochemical tests, chest X-ray, digestive endoscopy, colonoscopy, chest computed tomography, abdomen and pelvis computed tomography, abdominal ultrasound, and ambulatory blood pressure monitoring). Measurements of catecholamine and plasmatic renin activity were performed at rest and after physical exercise. Finally the patient underwent physiological and pharmacological autonomic tests that better diagnosed dysautonomia.
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PMID:Hormonal and cardiovascular reflex assessment in a female patient with pure autonomic failure. 1101 9

Angiotensin II receptor blockers have shown widespread efficacy as antihypertensive medications. These agents bind selectively to angiotensin II type 1 (AT(1)) receptors, specifically blocking the renin-angiotensin system at the last step in its cascade. CS-866 is the most recently introduced drug in this class. This article presents integrated safety and efficacy data from 7 randomized, double-blind, placebo-controlled, parallel group studies in which once-daily CS-866 monotherapy was used in the treatment of patients with essential hypertension (sitting diastolic blood pressure > or =100 mm Hg and < or =115 mm Hg). Data from a total of 2,145 CS-866-treated patients were included in the efficacy analysis. Safety data were available from 2,540 CS-866-treated patients, with a cumulative exposure of 5,888 patient-months. The antihypertensive efficacy of the drug was assessed using both cuff blood pressure measurements and 24-hour ambulatory blood pressure monitoring. The data show that CS-866 is effective and safe for the treatment of hypertension. Dose-dependent reductions in both diastolic and systolic blood pressures occurred within 1 week of initiating treatment, and the response was almost maximal within 2 weeks. There was no difference in efficacy between younger (<65 years) and older (> or =65 years) groups of patients. Trough-to-peak ratios showed that CS-866 retains the majority of its peak effect 24 hours after treatment, and is therefore suitable for once-daily dosing. Dizziness was the only treatment-emergent adverse event with which CS-866 was associated.
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PMID:Clinical studies of CS-866, the newest angiotensin II receptor antagonist. 1133 67

Although several investigations on mitral valve prolapse syndrome (MVPS) have been performed, clinical symptoms of this syndrome are not yet clarified. Atypical chest pain, palpitations, fatigue, dyspnea and anxiety are the most frequent symptoms associated with this syndrome. However, dizziness and syncope may be serious symptoms in MVPS. Dizziness and syncope are related to cardiac arrhythmias and are proposed to distinguish types, frequency of arrhythmias and relation to the symptoms. Orthostatic hypotension and tachycardia rarely occur in MVPS. The physiopathological mechanisms of these symptoms are not known clearly, but multifactorial causes are thought to be responsible including autonomic dysfunction, hyperadrenergic state, abnormalities in regulation of baroreceptors, parasympathetic derangements, decrease of intravascular volume, abnormal renin-aldosterone response to depletion of intravascular volume and abnormal release of atrial natriuretic factor.
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PMID:[Mitral valve prolapse syndrome: orthostatic hypotension and physiopathology of its clinical symptomathologies]. 1262 13


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