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)

The safety, tolerability and efficacy of PN 200-110, a new calcium antagonist with minimal negative inotropic effects, were studied in twelve patients with stable angina pectoris and coronary artery disease. The study design was single-blind and placebo-controlled and increasing doses of the drug were used on consecutive days to investigate a dose response relationship. Eleven patients completed the trial. Response to the drug was evaluated using symptom limited cycle ergometric exercise. PN 200-110 in all three tested doses of 2.5 mg, 5.0 mg and 10.0 mg significantly increased the resting heart rate (p less than 0.02) and the exercise time to the onset of angina pectoris (p less than 0.02). Doses above 2.5 mg did not appear to improve the exercise parameters evaluated. Four patients had side effects probably due to PN 200-110 but these were mild and included dizziness, headache and flushing. There were no abnormal results from haematological and biochemical screening or from urine testing. We conclude that PN 220-110 can be given safely to patients with coronary artery disease without producing deleterious effects on blood pressure either at rest or during exercise.
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PMID:Safety, tolerability and efficacy of PN 200-110, a new calcium antagonist in patients with angina and coronary heart disease. 624 Apr 5

Heart rate and blood pressure responses to low-level exercise tests in patients immediately before and after coronary artery bypass graft surgery lack sufficient documentation. This study documents heart rate, blood pressure, electrocardiographic responses and symptoms during low-level treadmill tests (LLTT) of 19 patients in two subgroups (A and B) before surgery, and again the day before hospital discharge. Preoperatively, the most common reason for stopping the treadmill test early was onset of angina. Postoperatively, patients stopped due to fatigue (4), dyspnea (6), and dizziness (2). Mean resting heart rate responses increased 37% in group A (n = 9) and 40% in group B (n = 10) from the preoperative to postoperative test. Mean postoperative resting pressure rate product responses increased 16% in group A and 38% in group B compared to preoperative values. Mean resting systolic blood pressure responses were 15% lower postoperatively for group A. This LLTT proved to be a clinically feasible tool which provided objective information about the patient's readiness for discharge and exercise prescription.
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PMID:Low-level exercise testing before and after coronary artery bypass surgery. 633 62

The pharmacokinetics, clinical efficacy, and adverse effects of three calcium-channel blocking agents--verapamil, nifedipine, and diltiazem--are reviewed. Verapamil, nifedipine, and diltiazem are absorbed well after oral dosing, but absolute bioavailability of each is reduced substantially by a first-pass effect. Each drug is metabolized extensively (verapamil and diltiazem to moderately active metabolites) by the liver. A substantial percentage of each drug is bound to plasma proteins, but the binding is of clinical importance only for nifedipine (92--98% protein bound). Intravenous verapamil has become the agent of first choice for treatment of acute paroxysmal supraventricular tachycardia (PSVT); use of chronic oral verapamil therapy for prophylaxis remains controversial. Verapamil and diltiazem have been evaluated with mixed results for atrial flutter and fibrillation. For treatment of myocardial ischemia, calcium-channel blockers may be of some value (possibly in combination with nitrates of B blockers). All three agents have been studied in patients with exertional angina with good results. Calcium-channel blockers appear to be equal with nitrates for treatment of variant angina. Patients with hypertropic cardiomyopathy have been treated with verapamil and nifedipine with promising results. Nifedipine has been effective for treatment of essential hypertension. Adverse effects of calcium-channel blockers have been relatively minor or infrequent. Diltiazem overall has the best side-effect profile, with adverse effects causing discontinuation of therapy in about 2--10% of patients; verapamil in intermediate (8--10%) and nifedipine the worst (17%) in this respect. The most common side effects generally are fatigue, headache, dizziness, skin rash, and peripheral edema. While they generally should be reserved for patients in whom more conventional therapy has failed (except those with PSVT), calcium-channel blockers appear to have a valid role as reserve agents for exertional and variant angina, cardiomyopathy, and hypertension.
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PMID:Update on calcium-channel blocking agents. 635 66

Bepridil, a calcium antagonist with a half-life of approximately 42 hours, was compared with placebo in a double-blind, randomized, crossover trial. Thirteen men (average age 62 years) with exercise-related angina pectoris and a positive exercise test (modified Bruce protocol) were studied. In the group as a whole, bepridil (400 mg once a day) caused an increased total exercise time (2.6 +/- 1.8 minutes, mean +/- standard deviation), time to onset of angina (3.3 +/- 1.6 minutes), time to 1 mm of ST-segment depression (2.2 +/- 2.3 minutes), time to 2 mm of ST-segment depression (2.4 +/- 1.4 minutes) and total work load achieved (1.8 +/- 1.4 kpm) compared with the preceding placebo phase (all p less than 0.05). Frequency of angina and nitroglycerin consumption were low and did not change significantly during bepridil therapy. Comparison of the 3 placebo periods (run-in, double-blind and washout) did not reveal a change in any measurement except time to onset of angina, suggesting no training effect or change in patient status. Adverse effects were common in patients taking both placebo and bepridil, but only 2 patients had adverse effects (dizziness) with bepridil that necessitated discontinuation of therapy. Similarity of the double product (systolic blood pressure X heart rate) at the end of exercise suggests a decrease in myocardial oxygen demand as the primary mode of action. This study suggests that bepridil is a promising agent for the treatment of exercise-induced myocardial ischemia.
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PMID:Effects of bepridil on exercise tolerance in chronic stable angina: a double-blind, randomized, placebo-controlled, crossover trial. 636 14

The efficacy and tolerability of nitroglycerin (NTG) ointment were studied in 80 male patients with severe angina pectoris. Two symptom-limited exercise tests were performed on successive days after application of an ointment containing 15 mg NTG or a placebo (P) ointment. The patients were assigned to 4 groups. The study was conducted in a double-blind, cross-over manner. The total amount of work performed was higher in all groups on NTG (46-70%) compared to P ointment. The difference was statistically significant (p less than 0.001) at all points of time from 0.5 to 7 hours. The ST segment depression in ECG at the end of the exercise test was slightly greater on P than on NTG, but the difference was statistically significant only in the 3-hour group (p less than 0.01). The frequencies of headache and dizziness were 35% and 16%, respectively, on NTG. Eight patients (10%) reported that headache was severe enough to prevent regular use of NTG ointment. NTG ointment is effective, has a long duration of action and is relatively well tolerated by patients with severe angina pectoris.
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PMID:Nitroglycerin ointment effective for seven hours in severe angina pectoris. 640 84

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 ECG-telephone-transmission (TTM) was used to record an ECG-strip during a typical symptomatic period in patients complaining of symptoms possibly caused by arrhythmias (palpitations, dizziness, paroxysm tachycardia, pulse irregularities; angina and dyspnea only if other reasons could be excluded). Patients complaining of syncope only were not admitted, because of the inability to make a telephone call successfully during such a symptomatic period. The ECG was transmitted to the CCU using a frequency modulation technique. In 60% of 196 patients an ECG-TTM could be achieved during a typical symptomatic period, whereas arrhythmias as cause for the symptoms could be excluded in 51 patients (26%). The remaining 66 patients (34%) demonstrated various arrhythmias ranging from simple SVPB and PVC to total AV-block and sustained VT. TTM, an easy-to-perform and cost-effective method allowed a successful ECG registration during a symptomatic period in almost two-thirds of symptomatic patients. In these patients arrhythmias could be verified or excluded as cause of the symptoms.
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PMID:[Value of ECG-telephone transmission in determining symptomatic heart-rhythm disorders]. 647 82

Verapamil hydrochloride, a prototype calcium antagonist, is now marketed in the United States for the acute treatment of supraventricular tachyarrhythmias and for chronic management of vasospastic and chronic stable angina. It inhibits the slow inward channel in in the heart and blocks calcium influx in smooth muscle. Its intrinsic negative inotropic action, which is apparent in isolated tissues, is offset in vivo by peripheral vasodilation. It has a mild, noncompetitive sympathetic antagonist effect; its most important electrophysiologic action is a depression of AV nodal conduction, accounting for its effect in supraventricular tachyarrhythmias. Its hemodynamic actions are characterized by a complex interplay of changes in preload, afterload, contractility, heart rate, and coronary blood flow. It does not depress cardiac function, except in severe heart failure. The drug has a mild dilator action on coronary arteries and reverses ergonovine-induced vasoconstriction. Controlled trials have established its role in Prinzmetal's variant angina, unstable angina, and chronic stable angina. It has also been found to be effective in obstructive cardiomyopathies. The potential role of verapamil in such conditions as hypertension, cardioprotection, and Raynaud's phenomenon needs further evaluation; at present these indications have not been approved by the Food and Drug Administration. The most common side effects include constipation, skin rash, and dizziness; AV block, heart failure, and sinus arrest may occasionally be encountered, especially when ventricular function is compromised or conduction system disease is present.
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PMID:Verapamil hydrochloride: pharmacological properties and role in cardiovascular therapeutics. 676 30

The antianginal action of a sustained-release preparation of isosorbide dinitrate (SUS-ID), administered twice a day, was examined in open trial in 61 patients with angina pectoris. The results obtained were as follows: 1) The frequency of anginal attacks as well as consumption of nitroglycerin tablets began to decrease significantly in the two weeks following the commencement of treatment with SUS-ID; increasing the dose and prolonging the period of administration resulted in further augmentation of its clinical effect. 2) The subjective symptoms improved in 44 of the 61 patients studied (72.1%), and 17 patients (27.9%) showed an improved electrocardiogram. 3) Both the systolic and diastolic blood pressures were significantly lowered, but little change in heart rate was observed. 4) According to the efficacy assessment by the doctors in charge, this drug was judged to be "effective and strongly recommendable" and to be "usable" in 56 of 61 patients (91.8%). Thus SUS-ID was considered to be of clinical usefulness. 5) In terms of side effects, 14 patients (23.0%) complained of headache and three patients (4.9%) of dizziness. These side effects, however, were not serious enough to cause withdrawal of the drug.
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PMID:Clinical effects of a sustained-release preparation of isosorbide dinitrate on angina pectoris. 677 14

The selective alpha, blocker prazosin was used to abolish Prinzmetal's variant angina in six patients. All had had an acute transmural myocardial infarction, after which the anginal attacks with transient ST segment elevation developed, and three of them had already suffered from variant angina prior to the infarction. Therapeutic trials with high doses of nifedipine, verapamil, nitrates, beta blockers, and (in one case) phenoxybenzamine were ineffective in all six patients. Prazosin, 8 to 30 mg/day combined with low-dose nitrates or nifedipine completely abolished the attacks in four patients, markedly reduced their frequency and intensity in one patient, and had to be stopped in the sixth one because of hypotension and dizziness. Except for this last patient, the drug was well tolerated by all the others, and no changes in blood pressure were observed. In four patients discontinuation or reduction of prazosin resulted in exacerbation of symptoms, but its renewal was followed by disappearance of the attacks. Since the mean follow-up period in this study was 4 to 6 months, further evaluation appears necessary concerning the long-term effects of this drug in Prinzmetal's variant angina.
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PMID:Prazosin therapy for refractory variant angina. 682 8


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