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)

Amlodipine, a potent long-acting dihydropyridine calcium antagonist, was compared with placebo in a parallel, randomized, double-blind study in 134 patients with chronic stable angina pectoris maintained on beta-adrenergic blocking agents. After a single-blind, two-week placebo period, patients were randomized to receive either amlodipine (2.5, 5, and 10 mg) or placebo once daily for four weeks. The effects of amlodipine on maximal exercise time, work, time to angina onset, and subjective indices including angina frequency, nitroglycerin tablet consumption, and patient and investigator ratings were assessed. Each dose of amlodipine produced increases in exercise time and calculated total work accomplished compared to baseline. Improvements at 5 and 10 mg were significantly greater than placebo which produced no significant change (p less than 0.05). Qualitative improvements in the severity of angina were produced by amlodipine at 5 and 10 mg daily assessed by patient-rating questionnaires (p less than 0.05). Reductions in angina frequency attacks per week and weekly nitroglycerin tablet consumption occurred but were not statistically significant when compared with placebo. Adverse effects observed during amlodipine treatment prompted discontinuation of treatment in only 2 out of 100 patients. Three patients discontinued treatment for reported lack of efficacy. No laboratory abnormalities prompted treatment discontinuation and minor side effects of dizziness, nausea, headache, and fatigue were observed infrequently. The results of this controlled, large-scale multicenter trial suggest that amlodipine significantly increased exercise capacity and was well tolerated when added to the antianginal regimen of patients remaining symptomatic while receiving beta-blocking agents.
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PMID:Amlodipine combined with beta blockade for chronic angina: results of a multicenter, placebo-controlled, randomized double-blind study. 135 85

Nitroglycerin was administered to eight healthy volunteers in the form of sublingual tablets, oral sustained-release tablets, and an oral solution. Blood samples were collected for measurement of nitroglycerin and its two isomeric glyceryl dinitrate metabolites. Blood pressure and pulse rate were monitored; subjective evaluations of headache, dizziness, facial flushing, skin irritation, and gastrointestinal upset were made. Nitroglycerin itself was virtually undetectable after the solution and tablet preparations; the metabolites were consistently detectable from a few minutes after dosing to 24 h later. Mean total (nitroglycerin plus metabolite) concentrations were comparable in the 15 min following sublingual administration, and the 8 h following tablet administration. The relative bioavailability of the tablets in comparison with the oral solution was 70 per cent based on metabolite concentrations. Nitroglycerin sustained-release tablets appear to exert their beneficial effects in the prolonged prophylaxis of angina through active metabolites.
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PMID:Pharmacokinetics of nitroglycerin and its metabolites after administration of sustained-release tablets. 155 Sep 9

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

A paired-comparison, multicenter study examined differences in patient and physician preferences for two transdermal nitroglycerin delivery systems, Nitro-Dur Transdermal Infusion System and Transderm-Nitro Transdermal Therapeutic System. For two weeks, 72 patients with angina pectoris wore both transdermal nitroglycerin patches simultaneously, each patch delivering half of each patient's need for nitroglycerin. (Each patch delivers nitroglycerin to the skin at a rate of about 0.02 mg/cm2 of patch per hour.) The patients and their physicians were then asked to rate the patches and to express their preferences with respect to eight patch characteristics: size, color, comfort, ease of application, adhesiveness, ease of removal, appearance, and associated redness/irritation. On each of the patch characteristics, significantly more of the patients expressed a preference for Nitro-Dur. Of the 67 patients who rated the patches overall, significantly more preferred Nitro-Dur (47 patients) than Transderm-Nitro (17 patients). Physician evaluations were also significantly biased in favor of Nitro-Dur. Treatment side effects included headache in 17 patients, application-site reactions in seven, nausea in four, dizziness in three, and fatigue in two. It is concluded that Nitro-Dur has greater patient acceptance than Transderm-Nitro and thus treatment compliance may be higher with Nitro-Dur than with Transderm-Nitro.
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PMID:A comparative evaluation of two transdermal nitroglycerin delivery systems: Nitro-Dur versus Transderm-Nitro. The Collaborative Investigation Group. 179 11

The efficacy and safety of bepridil hydrochloride (200 to 400 mg/day) were evaluated in patients with chronic stable angina refractory to maximal tolerated doses of diltiazem (median 360 mg/day) in a randomized, multicenter, double-blind, parallel study. Baseline diltiazem data were obtained during a 2-week period, after which 86 patients were randomized to bepridil (n = 46) or diltiazem (n = 40). Angina frequency, nitroglycerin consumption and ischemic manifestations induced by exercise treadmill testing were evaluated over 8 weeks. Bepridil significantly (p less than 0.05) increased time to angina onset, time to 1 and 2 mm of ST-segment depression, total exercise time and total work over baseline values. Changes in time to angina onset and time to 1 mm of ST-segment depression were significantly (p less than 0.05) greater for bepridil than for diltiazem. Angina frequency and nitroglycerin consumption did not differ significantly between groups. Compared with baseline, bepridil significantly (p less than 0.001) decreased heart rate (mean 4 beats/min) and prolonged QTc (mean 35 ms). The most frequent adverse effects in both groups were nausea, asthenia, dizziness, headache and diarrhea. Four patients taking bepridil and 1 taking diltiazem withdrew from the study because of adverse reactions. No sudden deaths, myocardial infarctions or instances of sustained ventricular tachycardia or torsades de pointes occurred in either group. The data indicate that bepridil provided safe and effective antianginal and antiischemic therapy in patients with chronic stable angina who exhibited less than optimal response to maximal tolerated doses of diltiazem.
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PMID:Comparative efficacy and safety of bepridil and diltiazem in chronic stable angina pectoris refractory to diltiazem. The Bepridil Collaborative Study Group. 185 72

Within a half-year period, we encountered six cases of patients harmed by the adverse effects of self-administered nitroglycerin--syncope, delayed definitive medical care, and the worsening of nonischemic symptoms. We therefore surveyed 112 patients after a remote myocardial infarction, and 121 cardiologists and internists, regarding the use of sublingual nitroglycerin. Of the physicians, 84 percent routinely prescribed nitroglycerin to patients after a myocardial infarction, and 79 percent of the patients had the tablets available (83 percent of these, at all times). Most patients used the tablets less than once per month, and 37 percent of the patients who always carried nitroglycerin had not used it at all during the preceding year. Although 89 percent of the patients claimed to know when to use the drug, 57 percent had used it or would use it for symptoms such as dizziness, rapid heartbeat, or presyncope. All patients having nitroglycerin claimed it relieved their symptoms, even if the relief was only partial, the time elapsed until relief could not be specified, and the symptoms were of a type unlikely to be relieved by the drug. We suggest that the practice of routinely prescribing nitroglycerin to patients after a myocardial infarction should be reassessed.
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PMID:Defining the proper role for self-administered sublingual nitroglycerin. A survey of physicians and patients. 190 18

Twenty-four healthy male subjects participated in a study comparing plasma concentrations of nitroglycerin generated by single applications of Nitradisc 32 mg, Transiderm-Nitro 50 mg and Nitro-Dur 104 mg patches and from one inch of Nitrobid 2% ointment. The three patch preparations are designed to release 10 mg nitroglycerin systemically over a 24 h period. Nitrobid ointment is intended to deliver 15 mg nitroglycerin per inch of ointment, and to be reapplied at least every 8 h. Blood was taken for nitroglycerin assay up to and including 24 h after each application. Assay for nitroglycerin was performed using a gas chromatography-mass spectrometry technique. Plasma concentrations of nitroglycerin were sustained up to the 24 h mark with all three patch preparations, but not with application of Nitrobid ointment. Nitrobid was associated with a rapid rise in nitroglycerin plasma concentrations maximal 1 h after application. Plasma concentrations of nitroglycerin absorbed from Nitrobid ointment fell below those absorbed from all three patch preparations after 8 h. Clinically, all four formulations were similar with respect to side effects, with headache and dizziness being the most common.
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PMID:Plasma levels of nitroglycerin generated by three nitroglycerin patch preparations, Nitradisc, Transiderm-Nitro and Nitro-Dur and one ointment formulation, Nitrobid. 308 98

In a study of GTN absorption during exercise and high ambient temperature, 12 healthy volunteers carried 10 mg glyceryl trinitrate (GTN, nitroglycerin) transdermal patches for 6 hours during each of 3 days. During a control day the mean plasma GTN concentration ranged from 1.0 nmol/L (SD +/- 0.8 nmol/L) to 1.5 nmol/L (SD +/- 1.0 nmol/L), whereas during a bicycle ergometer day mean GTN concentration was increased to 3.1 nmol/L (SD +/- 1.7 nmol/L, p less than 0.001). During a sauna day volunteers stayed for 20 minutes in a sauna, and mean GTN concentration in plasma rose to 7.3 nmol/L (SD +/- 1.7 nmol/L, p less than 0.001). Systolic blood pressure increased during exercise (p less than 0.01) but decreased significantly in the sauna (p less than 0.01). Headache was noted frequently (9 of 12 subjects) and dizziness by a few (3 of 12). The demonstrated increased transdermal absorption in our study may infer an increased effect during workload. Whereas the increase in transdermally absorbed GTN may be beneficial to the exercising angina patient, increased effects of GTN may be undesirable in hot surroundings. A study on angina patients is justified to assess whether this phenomenon bears clinical relevance.
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PMID:Increased uptake of transdermal glyceryl trinitrate during physical exercise and during high ambient temperature. 309 10

Forty-seven patients with chronic stable angina pectoris entered a thirteen-week open-label study with a transdermal therapeutic system of nitroglycerin in order to evaluate its clinical efficacy, safety, and patient acceptance. In 19 patients, a beta-blocker and in 17 patients a calcium-channel blocker were continued throughout the study period without alteration of their doses. The study consisted of a two-week run-in period and an eleven-week active drug period. Acute titration was done with nitroglycerin patches on the basis of weekly patient diaries on frequency of angina and sublingual nitroglycerin consumption. Overall, reductions in frequency of angina and in nitroglycerin consumption were statistically significant (p less than 0.05). Adverse reactions were common but tolerable. The reported side effects were headache in 32, skin rash in 18, dizziness in 10, palpitation and itching in 9 each, nausea in 7, flushing in 3, and vomiting in 1 patient. In conclusion, the present study demonstrates that individual dose titration with nitroglycerin patches for obtaining significant antianginal effect is essential. The present therapeutic system is convenient to use and well tolerated and had acceptable side effects in our study population.
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PMID:Clinical experience with a transdermal nitroglycerin system. 310 41

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


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