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)

Nifedipine antagonises influx of calcium through cell membrane slow channels, and sustained release formulations of the calcium channel blocker have been shown to be effective in the treatment of mild to moderate hypertension and both stable and variant angina pectoris. Preliminary findings also indicate that these formulations are effective in the treatment of Raynaud's phenomenon and hypertension in pregnancy, and that they reduce the frequency of ischaemic episodes in some patients with silent myocardial ischaemia. The exact mechanism of action of nifedipine in all of these disorders has not been defined. However, its potent peripheral and coronary arterial dilator properties, together with improvements in oxygen supply/demand, are of particular importance. A major goal of sustained release therapy is to permit reductions in the frequency of nifedipine administration, preferably to once daily, and thus improve patient compliance. Two new once-daily formulations--the nifedipine gastrointestinal therapeutic system (GITS) and a fixed combination capsule comprising sustained release nifedipine 20 mg and atenolol 50 mg--have exhibited marked antihypertensive efficacy. The GITS preparation has also been used effectively in the treatment of stable angina pectoris, and both formulations appear to be well tolerated. Sustained release nifedipine formulations are generally better tolerated than their conventionally formulated counterparts, particularly with regard to reflex tachycardia. Adverse effects seem to be dose related, are mainly associated with the drug's potent vasodilatory action, and include headache, flushing and dizziness. Generally, these effects are mild to moderate in severity and transient, usually diminishing with continued treatment. Thus, sustained release nifedipine formulations are useful and established cardiovascular therapeutic agents which have demonstrable efficacy in various forms of angina, mild to moderate hypertension and Raynaud's phenomenon. Further, promising results shown by the nifedipine GITS formulation, with its advantage of once daily administration suggest that it is likely to become one of the preferred nifedipine formulations for the treatment of hypertension and the various forms of angina.
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PMID:Sustained release nifedipine formulations. An appraisal of their current uses and prospective roles in the treatment of hypertension, ischaemic heart disease and peripheral vascular disorders. 171 8

Nitrendipine (Baypress; Bayer-Miles), a new calcium channel blocker, was administered to 38 hypertensive patients in an oral dose of 20 mg once or twice daily. Both systolic and diastolic blood pressures were reduced to a clinically relevant extent within 2 hours of taking the medication. There was no loss of effect during the 57 days of the trial. No significant changes in heart rate were noted. On the whole, side-effects were mild and transient and consisted mainly of dizziness, headache, joint pains and oedema.
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PMID:Evaluation of nitrendipine--a new calcium channel blocker. 201 61

Because of the benefit-risk ratio in their favor, calcium channel antagonists are considered to be a safe form of treatment of hypertension in the elderly. However, the outcome of dizziness in some patients over 65 yr old during the first few days of treatment with these drugs has to be considered. Five cases of "malaise" have been mentioned, which occurred during the first few days of treatment. The imputability of the drug in question has been evaluated. Additional factors have been found, ie orthostatic hypotension whatever its mechanism, and association with diuretics, with or without hyponatremia. The above-mentioned cases led to a study in 10 supine elderly women (mean age 85 +/- 3 yr) with normal blood pressure. In this study, systolic and diastolic blood pressure were monitored after a 20-mg oral dose of nicardipine for 3 h. Even in the supine position, a significant fall in blood pressure was observed as early as the 15th min after administration, which could be significant, occasionally reaching 45% of the initial value. Before administering a calcium channel antagonist to an elderly person, orthostatic hypotension has to be investigated. Association with a diuretic results in high risk due to hypovolemia that can enhance the vasodilatory effect of calcium antagonists.
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PMID:Dizziness in the elderly and calcium channel antagonists. 204 56

The use of calcium channel blockers is usual in cardiology today, but seem to spread to others specialties, particularly in the field of neuropsychiatry. The authors report the major clinical studies in neurology (treatment of migraines, epilepsia, dizziness and ischemic stroke) where flunarizine and nimodipine seem to have an important role. In psychiatry, their introduction is more recent. However, some encouraging results have been noted in the treatment of panic disorder, Gilles de la Tourette disease and mania.
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PMID:[Use of calcium inhibitors in neuropsychiatric pathology]. 219 69

We report the effects of the addition of nifedipine, a calcium channel antagonist, to the antiepileptic therapy of 20 patients with severe medically refractory epilepsy. Six patients developed side effects and in two the drug had to be discontinued because of these. The commonest side effects were headaches, dizziness and lethargy. Two patients experienced deterioration in seizure control and only 2 patients showed improved seizure control. One of these patients subsequently developed tolerance at 5 months. In 16 patients there was no change.
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PMID:Nifedipine as an add-on drug in the management of refractory epilepsy. 235 58

Nicardipine and nifedipine are structurally similar dihydropyridine calcium channel blockers with demonstrated efficacy in the treatment of stable angina pectoris. The present study was a prospective randomized trial designed to evaluate the relative incidence of dizziness, flushing, headache, pedal edema, and palpitations during use of these drugs in patients with angina pectoris. Of 250 patients who entered into the comparative treatment part of the study, 140 patients were susceptible to developing symptoms to nifedipine as identified during a 1-month open-label treatment with nifedipine. These patients were compared with a parallel cohort of 110 patients, who were identified during the same open-label period, but remained mostly asymptomatic. After a 1-week washout of nifedipine, equal numbers of patients in each cohort began an 8-week period of randomized, double-blind treatment with nifedipine (20 mg three times daily) or nicardipine (30 mg three times daily). Patients who experienced these symptoms during the open-label nifedipine treatment had a higher incidence of the same symptoms during the blinded treatment regimen. Nicardipine-treated patients had a lower incidence of each of the symptoms than did the nifedipine-treated patients. Statistically significant differences were reported for dizziness, the most common of the side effects. Patients who were free of these symptoms in the open-label period usually remained free of them in the blinded comparison. However, even among those free of dizziness during the open-label nifedipine treatment, more patients reported experiencing dizziness in the blinded phase from nifedipine than from nicardipine (18% vs 6%; p = 0.02).
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PMID:Randomized double-blind comparison of side effects of nicardipine and nifedipine in angina pectoris. The Nicardipine Investigators Group. 240 16

Throughout the developed world, populations are growing older. Blood pressure, especially systolic blood pressure, increases with aging, and this increase leads to increased risks of cardiovascular morbidity and mortality. Clinical trials demonstrate that treatment of hypertension in the elderly reduces overall cardiovascular mortality, cardiac mortality, nonfatal cardiovascular events, congestive heart failure, progression to severe hypertension, and strokes. Drug treatment has been well tolerated, but diuretic therapy has been known to increase plasma glucose, uric acid, and creatinine. Therapeutic trials of nonpharmacologic treatment may be indicated in those with mild elevation in blood pressure and no serious end organ disease. However, most people up to age 80 will require drug treatment. Many drugs are effective in the elderly, but, some like beta-blockers, may not be as effective as in younger patients. Controlled clinical trials demonstrate that nitrendipine, a calcium channel blocking drug, significantly reduced mean systolic and diastolic blood pressure in older hypertensive patients, (successfully controlling pressure in a high percentage) and was well tolerated. Drug effects persist for 12 h or more. The drug decreased the exercise-induced rise in the rate-pressure product. Although there is a temporary increase in heart rate, this returns to baseline after a short time. Side effects include headache, flushing, dizziness, edema, and palpitations. Therefore, nitrendipine offers a reasonable and useful alternative to many other drugs in the treatment of combined systolic and diastolic hypertension in the elderly.
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PMID:Epidemiologic aspects of elderly hypertensive patients and the results of treatment with nitrendipine. 248 68

1. The antihypertensive efficacy of a long acting formulation of the calcium channel blocking drug, nicardipine, was assessed using clinic and ambulatory (Remler M2,000) blood pressure measurements. 2. Eleven patients with essential hypertension (mean +/- s.e. mean; 173 +/- 6.6/103 +/- 1.9 mmHg) completed a randomised double-blind, placebo-controlled, cross-over study. The dose of nicardipine used was 60 mg twice daily for 4 weeks. 3. Mean ambulatory blood pressure was reduced from 164 +/- 5.3/97 +/- 2.9 to 151 +/- 5.2/88 +/- 2.4 mmHg (P less than 0.01); this effect was shown to be sustained for 8 h after the morning dose. Mean ambulatory heart rate was not significantly affected by treatment. 4. Clinic lying systolic blood pressure was reduced on treatment from 169 +/- 7.1 to 157 +/- 5.9 mmHg (P less than 0.2) and diastolic blood pressure from 99 +/- 3.6 to 89 +/- 3.9 mmHg (P less than 0.05). 5. One patient was withdrawn because of dizziness and flushing while on nicardipine; vasodilatory side effects such as headache, palpitations and flushing on nicardipine were noted by three patients. 6. We conclude that the long acting formulation of nicardipine studied in a dose of 60 mg twice daily is effective as monotherapy and is relatively well tolerated in mild hypertension. 7. This study highlights the importance of ambulatory blood pressure measurement in detecting significant changes in blood pressure, thereby permitting the study of small numbers of patients.
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PMID:The effect of slow-release nicardipine on ambulatory and clinic blood pressure in mild hypertension. 267 16

Most side-effects of calcium channel blockers are related to their pharmacological properties. This is best illustrated by the most common cardiovascular side-effects, which reflect the differences between the drugs of such a heterogeneous group. Side-effects related to excessive vasodilating activity (headache, dizziness, flushing, peripheral edema, and palpitations) are most likely with drugs such as nifedipine and other dihydropyridines, which are most active on vascular smooth muscle. Those related to depressed cardiac contraction and conduction are more likely with verapamil, whereas diltiazem is intermediate between the other two drugs. In the event of the occurrence of these adverse reactions, factors such as pharmacokinetics, galenic form, and the administration mode play a role. The pathological status of the patient also comes into play. Other less common reactions such as neuropsychic, gastrointestinal and endocrine effects and gingival hyperplasia appear as a consequence of the numerous sites of action of these molecules. Hepatic, haematological and cutaneous reactions appear to be relevant to immunological mechanisms. Therefore, most of the adverse effects of calcium channel blockers originate in the common mechanism of action of these drugs.
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PMID:[Side-effects of calcium inhibitors]. 267 81

The pharmacokinetics and relative bioavailability of oral isradipine, a dihydropyridine calcium channel blocking agent, were determined in 42 normal male volunteers participating in two separate studies. Eighteen of the subjects received 2.5-, 5-, and 10-mg oral doses of isradipine solution (Study 1). The remaining 24 subjects received four 2.5-mg capsules, one 10-mg capsule, and 10 mg of isradipine as an oral solution (Study 2). Venous blood samples were obtained prior to and at frequent intervals after administration of each dose form. Plasma isradipine concentrations were measured by radioimmunoassay. No significant dose effect occurred with respect to any pharmacokinetic parameter except AUC and Cmax in Study 1. In Study 2, Cmax, tmax, and MRT were significantly different after the solution compared with the capsular formulations. The respective pharmacokinetic parameters (mean +/- SD) for the 10-mg solution and 10-mg capsule in Study 2 were time to maximum concentration, 0.40 +/- .28 and 1.57 +/- 0.44 hours; oral clearance, 284.9 +/- 105.3 and 317.0 +/- 138.4 L/hr; elimination half-life, 5.36 +/- 1.8 and 6.63 +/- 2.4 hrs, respectively. Headache, dizziness, and tachycardia were the most frequent adverse effects in both studies.
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PMID:The pharmacokinetics of oral isradipine in normal volunteers. 296 65


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