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)

Twenty-two chronic hemodialysis patients with hypertension were treated with prazosin. Eight patients had volume-responsive hypertension, 11 volume-indpendent, and 3 high-renin hypertension. Blood pressure fell in all volume-responsive patients from a predialysis level of 175 +/- 5/100 +/- 3 to 148 +/- 4/75 +/- 3 mm Hg (p less than 0.001) after 3 months of therapy. Prazosin alone was effective in volume responsive patients at a dose of 5 +/- 1.0 mg daily. The blood pressure fell in volume-indpendent patients from 192 +/- 7/105 +/- 2 mm Hg predialysis to 155 +/- 6/80 +/- 3 after 3 months (p less than 0.001). Two were controlled on prazosin alone at a dose of 12 +/- 2 mg daily. Nine required 27 +/- 5 mg of prazosin daily as well as additional antihypertensive treatment. The blood pressure fell from 183 +/- 3/109 +/- 6 mm Hg predialysis to 173 +/- 17/85 +/- 3 mm Hg in high-renin patients after 3 months. One patient was controlled on 40 mg of prazosin daily. Two required 40 mg of prazosin daily as well as additional antihypertensive medication. Eleven patients described transient dizziness within the first month of therapy. One patient had recurrent syncope necessitating prazosin withdrawal; Prazosin is an effective antihypertensive agent which can be used in all types of hypertensive dialysis patients either alone or in combination with minimal side effects.
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PMID:Effects of prazosin in the control of blood pressure in hypertensive dialysis patients. 9 39

1. The antihypertensive effects of alpha-methyldopa and metoprolol have been compared in 110 patients (fifty-one males and fifty-nine females) with previously untreated essential hypertension (sixty-eight WHO stage 1 and forty-two WHO stage 2). 2. After 2 weeks of placebo, the patients were randomly allocated to treatment with either of the two drugs: alpha-methyldopa up to 500 mg b.i.d. and metroprolol up to 200 mg b.i.d. for 6 weeks. Periodical clinical, biochemical, haematological, radiological and electrocardiographical measurements were performed. 3. The average reduction in blood pressure produced by the two drugs was comparable. 4. In general, side-effects were few and tolerable: mainly bradycardia in the metoprolol group and dizziness and drowsiness in the alpha-methyldopa group. 5. The plasma renin activity was significantly reduced in the metoprolol but not in the alpha-methyldopa group.
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PMID:Antihypertensive activity of alpha-methyldopa on a twice daily regimen in comparison to metoprolol. A multi-centre controlled clinical trial. 35 27

To determine the influence of dietary sodium intake on the effects of hydrochlorothiazide (HCT) on blood pressure (BP), serum electrolytes, renin and aldosterone, nine male patients with uncomplicated essential hypertension were studied during the following therapeutic regimes: 1) sodium restriction alone (50 mmol/day), 2) sodium restriction combined with HCT (50 MG TWICE DAILY), 3) HCT alone, and 4) sodium restriction combined with HCT. Low sodium diet alone and HCT alone lowered BP to the same extent. The combination of HCT and sodium restriction had no extra effect on supine BP, but elicited complaints of dizziness and weakness in each patient, and overt orthostatic hypotension in three cases. Sodium restriction during HCT treatment caused hyponatraemia and aggravated hypokalaemia. Hyponatraemia could not be accounted for solely by changes in cumulative sodium balance. Plasma renin concentration rose markedly during the combined treatment. Plasma aldosterone was normal during HCT alone, but elevated when HCT was combined with sodium restriction. These results cast some doubt on the therapeutic value of prescribing a low sodium diet to patients with essential hypertension treated with thiazide diuretics. Overactivity of the renin-angiotensin-aldosterone system during this regime might explain both the lack of a beneficial effect on BP and the adverse influence on serum potassium.
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PMID:Influence of sodium intake on hydrochlorothiazide-induced changes in blood pressure, serum electrolytes, renin and aldosterone in essential hypertension. 69 14

Angiotensin-converting enzyme (ACE) inhibitors are useful first-line drugs in the therapy of mild and moderate hypertension. Adverse reactions to this drug class are rarely serious. Hypotension, cough, rash, and taste disturbance are uncommon; reduced glomerular filtration and hyperkalemia occur infrequently; angioedema is rare and neutropenia is extremely rare. Quinapril is a new ACE inhibitor that is converted to biologically active quinaprilat in the liver. This ACE inhibitor has a rapid onset of action and inhibits local tissue converting enzyme systems in kidney, heart, and brain, as well as in the circulating renin-angiotensin system. Clinically significant adverse effects of quinapril occur at low rates. In 1,771 patients receiving quinapril, the reported incidence of the first occurrence of orthostatic hypotension was comparable to that seen in patients receiving placebo. In other studies, headache was reported by up to 4.7% of patients receiving quinapril, which is comparable to reported incidences of headache in patients receiving other ACE inhibitors. Other adverse events reported at rates greater than 1% include cough with associated rhinitis and bronchitis, dizziness, and somnolence. Such adverse events have only rarely led to the withdrawal of patients from clinical studies of quinapril.
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PMID:Adverse effects of angiotensin-converting enzyme inhibitors in antihypertensive therapy with focus on quinapril. 154 39

We report a 52-year-old male patient with Shy-Drager syndrome (SDS) complicated by an occurrence of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). The patient first developed impotence at the age of 48, accompanied by urinary incontinence, and episodes of dizziness while standing. The following year, the patient had developed a staggering gait and speech became monotonous. At age 52, the patient was admitted to the hospital after experiencing frequent episodes of syncope associated with complete loss of consciousness. Upon examination, blood pressure was 100/70 in a recumbent position, and 80/60 when standing. The pulse rate varied from 60 per minute to 62. The patient was alert. The alternating Horner sign was observed, and a paucity of facial movements was visible. His speech was slow and monotonous. Muscle tone was increased bilaterally. There was incoordination. A laboratory examination revealed reduced serum sodium levels of 127 mEq/L and increased sodium excretion with plasma hypoosmolality (262 mOsm/kg/H), urine hyperosmolality and low serum renin activity (0.2 ng/ml/h). Renal functions were normal and the levels of adrenocortical and thyroid hormones were normal. There were no abnormalities observed in the chest roentgenogram taken. The level of antidiuretic hormone (ADH) was unreasonably high (5.74 pg/ml). A water-load test demonstrated failure of both water diuresis and inhibition of ADH secretion. These data suggested that hyponatremia in this case was caused by SIADH. The correlation between plasma osmolality and the concentration of ADH suggested that osmolality that initiates ADH release appeared to have been reset to around 230 mOsm/kg lower than normal.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Shy-Drager syndrome and the syndrome of inappropriate secretion of antidiuretic hormone]. 161 76

Orthostatic dysregulation (OD), originally a German-Scandinavian term partially corresponding to an Anglo-American concept of sympathotonic orthostatic hypotension, is characterised by altered cardiovascular control on standing, and its clinical features include dizziness, palpitation and, occasionally, orthostatic hypotension. The symptomatology suggests presence of cardiovascular adrenoceptor dysfunction, although the aetiology of OD has not been elucidated. The above situation prompted us to investigate autonomic nervous function in OD. The subjects were 8 patients with OD (20 +/- 2 years old; mean +/- SD), all of them fulfilled the diagnostic criteria accepted in Japan, and 6 healthy controls (17 +/- 3 years old). Noradrenaline and isoproterenol infusion tests and conventional haemodynamic functional tests (70 degrees passive head-up tilt, cold pressor test, Valsalva manoeuvre and Aschner's eye-ball pressure test) were carried out upon the subjects under the continuous measurement of blood pressure, pulse rate and respiration. Plasma vasoactive substances (noradrenaline, adrenaline, arginine-vasopressin and renin activity) were also determined in supine position and at 15 minutes after the 70 degrees passive head-up tilt. In noradrenaline infusion test, different doses (0.01 microgram/kg, 0.02 microgram/kg, 0.05 microgram/kg and 0.1 microgram/kg) of noradrenaline were administered by means of intravenous bolus injection, and a degree of subsequent rise in blood pressure was used as an index for the cardiovascular alpha-adrenoceptor sensitivity. In isoproterenol infusion tests cardiovascular beta 1- and beta 2-adrenoceptor sensitivities were assessed, respectively, by a degree of an increase in pulse rate and a degree of a fall in blood pressure following bolus injection of the drug (0.001 microgram/kg, 0.002 microgram/kg, 0.005 microgram/kg and 0.01 microgram/kg).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Cardiovascular alpha- and beta-adrenoceptor sensitivities in orthostatic dysregulation]. 216 87

The present single-blind, randomised, cross-over, placebo-controlled study was set up to compare the first-dose effects upon blood pressure (BP) and cerebral blood flow (CBF, measured by Xenon inhalation) of a single oral dose of atenolol 50 mg and enalapril 5 mg in ten hypertensive patients receiving a thiazide diuretic. It was found that a) the timing and degree of fall in BP after the first dose of atenolol and enalapril on a diuretic background were similar and generally not associated with symptoms or a fall in CBF, and b) dizziness, which is sometimes associated with the first-dose effect of ACE inhibitors in hypertensives on diuretics, can occasionally occur accompanied by a substantial fall (43%) in CBF in the absence of marked falls in systolic blood pressure. It is suggested that the latter event may be linked to a disturbance of cerebral autoregulation in part dependent on localised renin-angiotensin systems.
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PMID:First-dose effects of enalapril and atenolol upon blood pressure and cerebral blood flow in patients with mild hypertension on diuretic therapy. 219 32

The dihydropyridine calcium antagonist nitrendipine offers a pathophysiologically based antihypertensive treatment with a potent dilation of resistance vessels, increased arterial compliance, and an acute natriuretic/diuretic response. Prolonged nitrendipine treatment in essential hypertension is not associated with stimulation of the sympathetic nervous and the renin-angiotensin systems or accumulation of sodium and water. The antihypertensive effectiveness is similar to that of diuretics and beta-blockers, and the responsiveness appears to be greater in elderly and black patients. During long-term (approximately 1 year) nitrendipine treatment in mild to moderate hypertension, the blood pressure reduction is well sustained in "short-term" nitrendipine responders. In patients with severe hypertension, nitrendipine has a potent antihypertensive effect in combination with beta-blockers and/or diuretics. In mild-moderate hypertension, a single daily dose (10-40 mg) may be sufficient, whereas two daily doses (20-80 mg/day) seem necessary in severe hypertension. Common side effects are headache, flush, and palpitations (approximately 20-30%), but these are generally mild and transient. Dizziness and malaise occur in approximately 5%, often later during treatment. Peripheral edema in 5-20% of the patients is generally mild but persistent. Nitrendipine has no adverse effects on glucose and lipid metabolism or on plasma levels of electrolytes and urate. The ultimate aim of antihypertensive treatment is to prevent cardiovascular complications. As for other calcium antagonists, no study on primary prevention of cardiovascular complications in hypertension has been published. With regard to regression of left ventricular hypertrophy accompanying essential hypertension, conflicting results have been found with nitrendipine.
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PMID:Review of long-term trials with nitrendipine. 246 50

The specific competitive alpha 1-postsynaptic blocking action and haemodynamic effects of prazosin (Minipress) have been summarized. Prazosin causes dilatation of arterioles and veins, reduces total peripheral resistance as well as preload and afterload. Cardiac output does not change at rest, stroke volume and subsequent cardiac output increase during exercise. The changes in heart rate have non-significant. It does not cause sympathetic counter-regulation, plasma renin activity does not increase, aldosterone level decreases, salt- and fluid retention may rarely be observed. It does not provoke angina. The authors report on the results of their examinations with the first dose of prazosin in 61 patients (in 33 cases by the double-blind cross-over method by placebo control), and summarize the observations made with the drug in long-term treatment in Hungary. The authors and other teams used prazosin as a long-term treatment (of approximately 3 months) in combination with other drugs in a total of 344 patients, and as monotherapy in 159 patients. In the course of combination treatment side-effects were observed in 15% of the patients (dizziness, headache, weakness, occasionally palpitation). During monotherapy, side-effects occurred in 12% of the patients (tachycardia, headache, weakness, dizziness). Hungarian results confirm the usefulness of prazosin in all stages of hypertension. It is effective in 30-35% of the cases as a monotherapy (this rate is congruent with the efficacy of beta-blockers, calcium antagonists and antihypertensive drugs of central action). Earlier prazosin had been used as a third agent in combination treatment of hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The mechanism of the action of Minipress. Examinations in hypertension. 257 64

A tilt-table test was performed on 12 untrained subjects to evaluate the humoral adaptation to postural change. The observed peripheral reaction with a reversible short-term rise of norepinephrine (NE) and plasma renin activity (PRA) allowed us to divide the syndrome of the orthostatic dysregulation into a hyponoradrenergic and hypernoradrenergic type. This classification can be helpful for the clinical evaluation and therapy of orthostatic lability. The central excessive stimulation of the antidiuretic (ADH) and adrenocorticotropic hormone (ACTH) follow-ing orthostatic symptoms such as weakness or dizziness was not completely reversible within the observation period of 30 min. The ADH and ACTH increase was not different between the hypo- and the hypernoradrenergic type of dysregulation but was the most sensitive indicator of orthostatic lability: 41% of all subjects showed a hypernoradrenergic orthostatic dysregulation with pronounced NE response and alpha 2-adrenoceptor down-regulation. By use of antiembolism stockings (AES) or dihydroergotamine (DHE) this rate decreased to 16%. This was associated with a significantly reduced NE and PRA response and a diminished alpha 2-adrenoceptor number.
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PMID:Humoral regulation of the orthostatic reaction. 284 55


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