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Query: UMLS:C0012833 (dizziness)
 9,689 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The hemodynamics influencing effect of Nitromint sublingual tablet and aerosol (EGIS Pharmaceuticals) has been examined in 22 ischaemic heart disease patients during heart catheterisation. The patients were hospitalized and took also the earlier prescribed drugs. On the basis of the results of examinations it may be concluded that Nitromint aerosol has a therapeutic action comparable to other short-acting nitrate preparations such as sublingual nitroglycerin tablet. According to the observations of the patients the drug action develops within a significantly shorter period. Considering the type of side-effects there was no difference between the two drug forms. Primarily, Nitromint tablet caused systemic effects (headache, dizziness, throbbing head) while aerosol caused predominantly local symptoms (burning of the tongue, disagreeable taste). These effects were only temporary and ceased within 10 minutes. According to the above described observations Nitromint aerosol may successfully be used as a new nitroglycerin containing drug form in all forms of angina pectoris: in rest angina, effort angina, as a prophylaxis, in mixed type angina pectoris, as a first-aid in emergency cases in acute left heart failure, preceding the application of infusion.
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PMID:Comparative haemodynamic examination of Nitromint (sublingual tablet and aerosol). 158 77

We conducted a randomized controlled hemodynamic study to evaluate the effect of placebo and 20 mg isosorbide-5-mononitrate, a long-acting organic nitrate, in 19 patients with HBsAg-positive cirrhosis by the simultaneous measurement of portal venous pressure and wedged hepatic venous pressure. Baseline values for the two groups were similar. One hour after oral administration of 20 mg isosorbide-5-mononitrate in 10 patients, mean arterial pressure, mean pulmonary arterial pressure and pulmonary capillary wedge pressure significantly decreased from 92 +/- 13 (mean +/- S.D.) to 82 +/- 14 mmHg, from 12.9 +/- 4.5 to 9.3 +/- 2.4 mmHg and from 6.9 +/- 3.4 to 4.3 +/- 1.8 mmHg, respectively. However, both portal venous pressure gradient (from 18.1 +/- 3.6 to 17.5 +/- 3.0 mmHg) and hepatic venous pressure gradient (from 17.8 +/- 5.2 to 16.6 +/- 5.3 mmHg) remained unchanged during the study. In six patients who received 20 mg isosorbide-5-mononitrate twice daily for 7 days, hepatic venous pressure gradient remained unaltered as compared to basal and 1-hr values. There was no significant change in cardiac index, heart rate or systemic vascular resistance in either immediate (1-hr) or delayed (7-day) studies. Three patients (30%) developed mild headache or dizziness and two patients (20%) demonstrated systolic hypotension (less than mmHg) during the immediate study. This study shows that isosorbide-5-mononitrate appears to have no effect in treating portal hypertension in patients with HBsAg-positive cirrhosis. In addition, the isosorbide-5-mononitrate may affect the systemic circulation more than the portal circulation.
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PMID:Lack of effects of isosorbide-5-mononitrate on hepatic hemodynamics in HBsAg-positive cirrhosis. 275 46

Isosorbide dinitrate (ISDN) improves the clinical and hemodynamic state of patients with heart failure, but may cause dizziness and syncope. To characterize patients in whom cardiac output falls with high-dose nitrate therapy and to examine further the pathophysiology of the fall in cardiac output in these patients, we studies the effect of sublingual ISDN on forward cardiac output in 14 patients with severe cardiac failure (New York Heart Association grades 3-4). We examined systolic and diastolic left ventricular (LV) function from pressure and volume analyses of LV function. After administration of 15 mg ISDN, cardiac output was either unaltered or increased in 7 patients (Group 1) (11 +/- 12%, mean +/- SD), and decreased in 7 (Group 2) (-13 +/- 10%) (Group 1 vs. 2, p less than 0.002). Initial systemic arterial pressure, LV ejection fraction, wedge and LV transmural filling pressures were similar in both groups, but Group 2 patients had a lower systemic vascular resistance (p = 0.07) and tended to have a larger initial LV end-diastolic volume and increased end-diastolic compliance; following ISDN the decrease in LV filling pressure and end-diastolic volume was larger and the product of the changes greater (p less than 0.02). Thus ISDN decreases filling pressure and improves forward cardiac output in some patients with congestive heart failure, but large doses may decrease cardiac output in a subset of patients who have a lower systemic vascular resistance and a larger more compliant ventricle, maintaining forward blood flow predominantly by a preload reserve mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of isosorbide dinitrate on cardiac output in severe cardiac failure: relation to initial hemodynamics, ventricular volume, and the preload reserve mechanism. 279 73

Nitrate usage worldwide is on the increase as the indications for therapy expand. Present indications for nitrate therapy include chronic stable angina pectoris, unstable angina pectoris, complications of acute myocardial infarction, and 'unloading' therapy for acute and chronic congestive heart failure. Nitrates are also being used in the operating suite by anaesthesiologists to control systolic blood pressure during various surgical procedures. New nitrate delivery systems have recently become available which provide considerable dosing flexibility, further increasing the interest in this group of compounds. The dominant action of nitrates is a direct effect on vascular smooth muscle, producing vasodilation of the veins and arteries. These drugs decrease myocardial work by lowering systolic blood pressure, systemic vascular resistance, and reducing intracardiac dimensions. In addition, nitrates have a potent effect on cardiac preload as a result of systemic venodilatation. There is also some evidence that nitrates exert direct effects on the coronary circulation (vasodilatation of coronary arteries and coronary collateral vessels, and direct atherosclerotic stenosis dilatation). These actions may play a role in relieving myocardial ischaemia. Adverse sequelae of nitrate therapy are well known and serious adverse reactions are uncommon. Headache and dizziness are the most frequent side effects. Nitrate tolerance is a definite problem - present evidence indicates that long acting formulations, high doses, or frequent dosing regimens are particularly likely to induce vascular tolerance to nitrates. Consequently, provision of a nitrate-free interval has taken on increasing significance as a strategy to avoid tolerance. Nitrate delivery systems are numerous. Although availability varies from country to country, in most countries there are a wide variety of formulations of glyceryl trinitrate (nitroglycerin) available, including sublingual and oral tablets, oral spray, topical ointment as well as discs or patches for transdermal administration, a transmucosal tablet and an intravenous formulation. Similar formulations of isosorbide dinitrate, except buccal tablets, are available in some countries. Isosorbide 5-mononitrate, a potent metabolite of isosorbide dinitrate, is achieving increasing popularity as an antianginal drug. Optimum nitrate therapy requires a good understanding of the properties of the various formulations, particularly onset and duration of action and propensity to induce tolerance.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Glyceryl trinitrate (nitroglycerin) and the organic nitrates. Choosing the method of administration. 311 8

Among 509 patients referred to our Institute for Holter monitoring, between 1st September, 1982-30th October, 1983, 28 patients aged 65-90 (mean 76) were referred for dizziness and syncope. There were 17 men and 11 women. Seven patients had a M.I. in their past, 4 angina pectoris, 5 hypertension, 4 aortic stenosis or aortic insufficiency or both, hemodynamically significant, one had mitral valve prolapse (MVP) and one transient ischemic attacks (TIA). In our series 16 out of 28 patients received digoxin and antiarrhythmic drugs (quinidine, propranolol, procainamide, Neo-gilurythmal, amiodarone), 2 of them digoxin and quinidine in full doses and one digoxin and amiodarone. Other drugs administered to our patients included Aldomin, Isordil, Lasix, aminophylin, cromoglycate etc. In 10 patients (35.7%) we found complex ventricular arrhythmias (7 with M.I., 3 patients of 4 with significant aortic valve lesion, 2 patients of 2 with left anterior hemiblock (LAH), 1 patient with MVP, 1 patient with TIA). In another 5 patients (17.8%) we found atrial fibrillation, fast rhythm (2 with chronic obstructive lung disease, 2 with hypertension and 1 in post M.I.) which explained their symptomatology. From our data we conclude that the pluripathology found in old age as well as the multimedication administered, cause a plurietiology of syncope, arrhythmias playing an important role in its determination, in this particular age group.
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PMID:Holter monitoring for dizziness and syncope in old age. 387 98

Nitrates are potent relaxers of vascular smooth muscle and act by dilating veins, arteries, and arterioles (especially at high doses). Their clinical effects have been considered to be dominantly related to peripheral actions: systemic venodilatation and a decrease in systemic vascular resistance, reducing the preload and afterload of the heart. Considerable experimental work confirms potent salutary effects on the coronary circulation. These drugs are readily absorbed across mucosal surfaces; they are available in multiple formulations, including sublingual, buccal, oral, and topical delivery systems. Nitrate administration should begin with low doses and increased to doses that are often higher than previously recommended until a specific clinical end point or limiting side effects occur. Organic nitrate esters are effective in the treatment of stable angina pectoris, unstable angina, coronary vasospastic syndromes, and in vasodilator therapy in severe congestive heart failure. The pathophysiology of these syndromes is reviewed with respect to the clinical actions of nitrates on the central and peripheral circulations. The side effects of nitrates include headache, dizziness, and nausea. Nitrate tolerance, a controversial subject, does not appear to be an important clinical problem. Using the guidelines presented in this review, nitrate therapy provides effective, inexpensive, well-tolerated therapy for many patients with cardiovascular disease.
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PMID:Nitroglycerin and long-acting nitrates in clinical practice. 640 16

The safety and tolerability of intermittent (16 hours on/8 hours off) nitrate patch therapy (0.2, 0.4 or 0.6 mg/hr: dose adjusted as required) was studied for a median duration of 356 days in 106 patients (mean age 60.9 +/- 8.6 years) with angina pectoris. Most patients (82%) were on existing beta-blocker and/or calcium antagonist therapy. Safety, tolerability and efficacy data were obtained by means of patient diary cards and regular clinic visits. Almost 90 treatment years revealed no significant or serious adverse events, and there were no changes in haematology or biochemistry associated with intermittent nitrate patch therapy. The most frequently reported side-effects were headache, skin reactions and dizziness (53%, 20% and 8% of patients respectively). Treatment resulted in a sustained reduction in the frequency and severity of angina attacks, reduced sublingual GTN consumption, an improvement in general wellbeing and a rise in the proportion of patients in whom angina was controlled.
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PMID:The long-term safety and tolerability of transdermal glyceryl trinitrate, when used with a patch-free interval in patients with stable angina. 826 Mar 32

Sildenafil citrate, an oral therapy for erectile dysfunction, is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5), the predominant isozyme metabolizing cGMP in the corpus cavernosum. Chemically, it is a compound of the pyrazolo-pyrimidinyl-methylpiperazine class. Sildenafil has no direct relaxant effect on human corpus cavernosum but enhances the relaxant effect of nitric oxide (NO) on the corpus cavernosum by inhibiting PDE5, which is responsible for degradation of cGMP in this tissue. When sexual stimulation causes local release of NO, inhibition of PDE5 by sildenafil increases concentrations of cGMP in the corpus cavernosum, causing smooth muscle relaxation and blood flow into the penis, resulting in an erection. Sildenafil at recommended doses has no effect in the absence of sexual stimulation. The drug is rapidly absorbed after oral administration, with absolute bioavailability of 40%. Its pharmacokinetics are dose proportional over the recommended dosage range. Maximum plasma concentrations are reached within 30 to 120 minutes after oral dosing in the fasting state. Sildenafil is cleared predominantly by the hepatic microsomal isoenzymes CYP3A4 (major route) and CYP2C9 (minor route). Clinical studies assessed the effect of sildenafil on the ability of men with erectile dysfunction to engage in sexual activity and, specifically, to achieve and maintain an erection sufficient for satisfactory sexual intercourse. Sildenafil was evaluated at doses of 25, 50, and 100 mg in randomized, double-masked, placebo-controlled clinical trials of up to 6 months' duration. The drug was administered to hundreds of patients aged 19 to 87 years having erectile dysfunction of various etiologies for a mean duration of 5 years. Sildenafil was associated with statistically significant improvement in erectile function compared with placebo. Adverse effects reported at a rate of >2% were headache, flushing, dyspepsia, nasal congestion, urinary tract infection, abnormal vision, diarrhea, dizziness, and rash. No cases of priapism were reported. The use of sildenafil is contraindicated in men who are taking organic nitrates, because of the potential for a precipitous decrease in blood pressure. Postmarketing reports and surveillance have revealed at least 39 deaths with sildenafil use in men having a history of heart disease, men taking nitrate medications, and men in poor physical health due to lack of exercise. Many of the men who experienced serious adverse effects or death had a variety of concomitant diseases and were taking multiple medications.
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PMID:Safety and efficacy of sildenafil citrate in the treatment of male erectile dysfunction. 991 1

Sublingual (SL) apomorphine (2 to 6 mg) has been shown to be effective for treatment of male erectile dysfunction. Many patients with erectile dysfunction are also being treated for systemic hypertension and/or cardiovascular disease. In a double-blind, randomized, placebo-controlled, crossover trial, SL apomorphine 5 mg and placebo were administered on alternate days to 162 men who were on long-term therapy (> or =4 weeks) with angiotensin-converting enzyme inhibitors, beta blockers, diuretics, calcium channel blockers, alpha(1) blockers, or short- or long-acting nitrates. Blood pressure and heart rate were measured before and after dosing; cardiac rhythm was recorded by 4-hour Holter monitoring. The only potentially clinically significant interactions between SL apomorphine and the antihypertensive agents or short-acting nitrates were greater orthostatic decreases in systolic blood pressure in the alpha-blocker and calcium channel blocker groups (-10 and -6 mm Hg vs placebo, respectively). Administration of SL apomorphine after dosing with long-acting nitrates resulted in significant decreases in blood pressure when patients were standing (mean systolic change, -5 to -9 mm Hg 30 to 60 minutes postdose, p <0.05; mean diastolic change, -3 to -4 mm Hg 50 to 60 minutes postdose, p <0.05). The most common adverse events with SL apomorphine were dizziness, nausea, and headache. Syncope occurred in 1 patient in the beta-blocker group; symptomatic hypotension occurred in 2 patients each in the short- and long-acting nitrate groups. Thus, in patients receiving common antihypertensive agents and short-acting nitrates, as well as in most patients receiving long-acting nitrates, SL apomorphine at higher than recommended doses produced no clinically significant changes in heart rate or blood pressure greater than changes seen with SL apomorphine alone.
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PMID:Cardiovascular safety of sublingual apomorphine in patients on stable doses of oral antihypertensive agents and nitrates. 1158 43

Nitrates are very effective antianginal and anti-ischaemic agents. Provision of a long nitrate-free interval or low plasma nitrate levels prior to the morning dose prevents the loss of clinical efficacy by preventing the development of tolerance. However, side effects during nitrate therapy are common. Headache is the most common side effect of nitrates; often dose-related and reported by up to 82% of patients in placebo-controlled trials. Nearly 10% of patients are unable to tolerate nitrates due to disabling headaches or dizziness. In others, headaches are mild-to-moderate in severity and either resolve or diminish in intensity with continued nitrate therapy. Nitrate-induced hypotension is common, but often asymptomatic. In rare instances, nitrate-induced hypotension is severe and accompanied by marked slowing of the heart rate and syncope. Use of nitrates in patients who experience syncope after administration of nitrates is contraindicated. Nitrates rarely cause coronary steal and myocardial ischaemia. Nitrate rebound may occur and patients may experience nocturnal anginal episodes during intermittent therapy with nitroglycerin patches. Administration of nitrates is contraindicated with concomitant use of phosphodiesterase-5 inhibitors used for the treatment of erectile dysfunction, as combination therapy may lead to profound hypotension and even death. There are disturbing observational reports in the literature that continuous, prolonged use of nitrates may lead to increased mortality and recurrent myocardial infarctions. Large, randomised, placebo-controlled studies are needed to confirm or refute these reports; until then, the use of nitrates to treat angina is here to stay.
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PMID:Side effects of using nitrates to treat angina. 1690 56


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