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Query: UMLS:C0018681 (headache)
 56,091 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Calcium channel blockers are recently developed antihypertensive drugs. In terms of mechanisms of action, their specificity is not so well established as that of angiotensin converting enzyme inhibitors but is better understood than that for diuretics or adrenergic-inhibiting drugs. Calcium channel blockers were originally developed for treatment of angina but were found to lower arterial pressure as well. Three of them are now in wide use in the United States; their therapeutic spectrum in regard to type of hypertension is broad. Sublingual nifedipine has replaced intravenously administered vasodilators as immediate treatment of severe hypertension, and all three drugs, given orally, have been shown to be effective in mild, moderate, and severe hypertension. The three drugs available in this country are verapamil, diltiazem, and nifedipine. Pharmacological studies have shown that verapamil has the most negative chronotropic and inotropic effects of the three, with nifedipine producing the most vasodilation and having the potential for causing reflex tachycardia. Actually in practice, these various pharmacological differences have proved to have less significance than previously thought, and the drugs seem to have about equal antihypertensive effectiveness. Comparisons of calcium entry blockers with other drugs have shown them to be equally effective in whites as propranolol but more effective in blacks. Responsiveness appears to be related, as well, to pretreatment plasma renin activity and age. Thus, the antihypertensive effect is directly related to age and inversely related to plasma renin activity. The side effects mostly relate to vasodilation, reflex tachycardia, palpitations, headache, and edema; they are not frequent, and the drugs are well tolerated.
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PMID:Calcium channel blockers. Potential medical benefits and side effects. 249 Aug 17

The efficacy of continuous and intermittent nitroglycerin patches (10 mg/day) was compared in a randomized, placebo-controlled trial in 36 patients with stable angina and reproducible, exercise-induced ST depression. Intermittent treatment was administered either 18 or 14 h/day with an intermission of 6 h or 10 h, respectively. Exercise tests were performed during the last 2 h of patch application. Compared with placebo, neither continuous nitroglycerin nor the two intermittent regimens prolonged total treadmill time or time to 1 mm ST depression. No treatment eliminated exercise-induced ST depression in greater than 1 of the 36 patients. Time to angina was prolonged (by 40 +/- 66 s) only during the "10 h off" treatment (p = 0.001); time to angina increased by greater than or equal to 20% in 13 patients. Responders to treatment could be predicted by a short history of angina (p less than 0.05) and a time to angina less than or equal to 250 s during the placebo test. For each treatment, greater than or equal to 25 of the patients reported headache; 4 additional patients dropped out because of severe headache and 2 others because of a coronary event in a washout period. Thus, in most patients with stable angina, side effects outweight any benefit demonstrable with this therapy.
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PMID:Limited usefulness of intermittent nitroglycerin patches in stable angina. 249 22

The anti-anginal effect of sustained release diltiazem, isosorbide-5-mononitrate (IS-5-MN) and their combination has been evaluated in 25 patients in 4 blinded treatment periods of 2 weeks each. The number of anginal attacks during each treatment period was reduced from a mean of 23 during placebo to 15 during diltiazem and 15 during combination therapy, but it was not significantly changed after IS-5-MN-20. A similar pattern was seen for nitroglycerin consumption and number of angina-free days. Maximal exercise capacity was also significantly improved following diltiazem and the drug combination, and it was not changed after IS-5-MN. ST segment depression was less pronounced after diltiazem and the combination compared to IS-5-MN. There was no difference in exercise capacity or ST segment change between diltiazem and the combination. The PR interval was slightly prolonged after diltiazem, but this was of no clinical importance. Adverse effects of diltiazem treatment were rare. Headache was common following IS-5-MN (13 patients) and the combination (11 patients). Thus, sustained-release diltiazem was of value in the treatment of chronic stable angina pectoris, whereas IS-5-MN was not effective, either as a single therapy or in combination with diltiazem. The reason for the inefficacy of IS-5-MN is not known, but the development of tolerance and an inadequate dose are possible explanations.
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PMID:Effects of diltiazem and isosorbide-5-mononitrate, alone and in combination, on patients with stable angina pectoris. 250 59

Nitrates are old drugs, introduced into medical treatment more than 100 years ago, initially as a homeopathic remedy against headache (1850), and only later against angina pectoris (1867). Their typical hemodynamic, antiischemic effects were described in man in the 1950s and 1960s. They include: a reduction in venous return, lowering of the abnormally increased left ventricular enddiastolic pressure during ischemia, a decrease in left ventricular systolic wall stress, and changes in left ventricular geometry resulting in a decrease of myocardial oxygen consumption. The vasodilatory effect on large epicardial coronary arteries, especially on eccentric stenoses through relaxation of vascular smooth muscle tone was described even more recently (1980). This effect proved to be of considerable clinical importance both in angina at rest, that is during a primary increase in vasomotor tone (coronary artery spasm) as well as in angina provoked by exercise, where the increase in vasomotor tone and in the degree of stenosis is often due to a rise in alpha-sympathetic tone. The relaxing effect on the large coronary arteries is regarded as additive to the one on venous tone. The real clinical importance of nitrates became, however, evident only in the last decade with the discovery of EDRF, the so-called endothelial-derived relaxing factor, an endogenous compound of endothelial origin at least partly consisting of nitrous oxide and therefore, like nitrates, it exerts its effect through the stimulation of cGMP. The tendency for coronary arteries to constrict in presence of atherosclerosis is explained by the lack of EDRF, especially in the region of atherosclerotic plaques where the endothelium is often absent or has lost its endocrine function.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[The mechanism of action of nitrates, 1988 status]. 251 90

Nicorandil is a vasodilator that acts on the venous and arterial beds of the systemic circulation. It reduces both cardiac preload and afterload, as well as improving coronary blood flow. The present study assessed the efficacy, tolerability, duration of action and optimal single dose of nicorandil in patients with stable angina pectoris. Treadmill exercise tests were undertaken by 8 patients at 2 and 6 hours after single oral doses of 20, 40, and 60 mg of nicorandil, and placebo. Doses were administered at weekly intervals in this double-blind, cross-over study. The duration of exercise to onset of angina was increased by 58, 96 and 125 seconds over baseline values (p less than 0.01) with the 20-, 40- and 60-mg doses of nicorandil, respectively. Significant improvement in exercise capacity compared with the effects of placebo was maintained at 6 hours after administration. The antianginal activity was accompanied by a marked reduction in blood pressure both at rest and during exercise, which resulted in severe dizziness and fainting in 2 of 6 patients after the 60-mg dose. However, significant reflex tachycardia occurred only at 2 hours after the 60-mg dose. Plasma concentrations of nicorandil correlated with percent reductions in blood pressure at 2 hours after administration (p less than 0.001) and with increasing total exercise work load (p less than 0.01). The incidence of adverse events appeared to be dose related. Headache and dizziness accounted for most of the reported events. The 20-mg single dose of nicorandil was considered to provide the best combination of antianginal activity and tolerability in this study.
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PMID:A controlled single-dose study of the efficacy, dose response and duration of action of nicorandil in angina pectoris. 252 28

In 242 patients with hypertension and/or angina pectoris, a new cardioselective betablocker without ISA, bisoprolol (Concor), was tested. The average mean value of 168/102 mm Hg was lowered in the 174 hypertensive patients by a systolic value of 17 and a diastolic value of 11 mm Hg. A normal diastolic pressure of 95 mm Hg or below was attained within 4 weeks in 73% of patients. Angina pectoris improved from 7 attacks per week before treatment to 3 attacks after 2 weeks; patients with additional hypertension showed a further improvement after another two weeks to an average of 1.7 attacks per week. Side effects were most frequently dizziness, headache and fatigue and also a few patients with gastrointestinal symptoms, an unusual side effect with this treatment. The results show the effective antihypertensive and antianginal action of bisoprolol in a large group of outpatients.
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PMID:[A new beta 1-receptor blocker in the therapy of essential hypertension and angina pectoris]. 256 85

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

Within the last decade it became obvious that the treatment of angina pectoris alone is not sufficient. Modern goals include the optimization of anti-ischemic treatment ("silent myocardial ischemia") without compromising quality of life, as well as the reduction of fatal and non-fatal cardiac events. The failure of nitrates to continuously protect from myocardial ischemia ("nitrate tolerance") requires a modification of the current step-care recommendations for medical treatment. Numerous combinations of nitrates, betablockers and calcium channel blockers compensate for each other regarding their effects on heart rate, contractility, peripheral resistance and coronary blood flow. Recommendations for combination therapy decisively depend on the choice of the first-line drug. Only nitrates reduce myocardial preload by venodilation and substitute for EDRF-deficiency. After headaches disappear, nitrates do not affect quality of life and they are cheap. The nitrate-induced acceleration of heart rate should be compensated by the addition of beta-blockers or heart rate-decreasing calcium channel blockers. Therefore, the combination of nitrates with heart-rate-increasing calcium channel blockers, such as nifedipine, should be avoided. Many studies have proven the superiority of different double and triple therapies, as compared to their single components. A few reports, however, did not confirm this increase of anti-ischemic efficacy with combination therapy. The improvement of prognosis is proven for beta blockers without ISA in subgroups of patients with acute or post myocardial infarction and can be assumed for nitrates as well. With regard to prognosis, calcium channel blockers were inferior to nitrates and beta blockers. The combination of nitrates with a non-ISA betablocker should be preferred in post myocardial infarction patients with ventricular arrhythmias, whereas the combination of nitrates with a heart rate decreasing calcium channel blocker should be preferred in patients with COPD, severe peripheral arterial disease or severe diabetes. The combination of nitrates with a heart-rate-increasing calcium channel blocker should be considered in patients with sinus bradycardia, first degree AV-block, or proven coronary spasm. In patients with congestive heart failure, betablockers and calcium channel blockers should be avoided. To optimize medical treatment of ischemic heart disease, intermittent high dosage ISDN plus a beta blocker without ISA or ISDN plus a calcium channel blocker like verapamil are recommended. Frequently, however, the patient decides by himself, based on unacceptable side effects.
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PMID:[Combination of anti-angina drugs]. 257 81

The primary aim of this multicentre, randomised, double-blind, crossover study in 529 patients with stable angina pectoris was to compare the tolerability of epanolol, a novel antianginal agent, administered as a single oral daily dose of 200mg, with an oral retard formulation of twice-daily nifedipine 20mg and to determine patient preference (VISA 2). Confirmation of equal efficacy and safety monitoring were secondary aims of the study. Treatment consisted of 4 weeks on each therapy, and at the end of the study each patient was asked to state their treatment preference. 448 patients (85%) answered the preference question. Preliminary analysis of the data showed that 61% of patients preferred epanolol vs 31% who preferred nifedipine (p less than 0.001). Reason for a preference for epanolol were mainly fewer adverse experiences (11% vs. 23% with nifedipine), a general improvement in well-being (16% vs 10% with nifedipine) and a decrease in the number of angina attacks (11% vs 10% with nifedipine). A tolerability questionnaire comprising 43 questions and covering 7 different body systems showed that epanolol had a better profile than nifedipine for the following 7 side effects: poor sleep, abdominal pain, flushing, swollen ankles, palpitations, headache and a general feeling of being unwell. Four patients died during the study; none of the deaths were associated with the study treatment. Treatment with nifedipine resulted in 63 patient withdrawals compared with 31 patient withdrawals during epanolol treatment; there were 5 patient withdrawals from both treatments. The main reasons for withdrawal of patients from nifedipine treatment were adverse events (9% vs 4% with epanolol) and a lack of efficacy (3% vs 2% with epanolol).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Comparative multicentre study of the tolerability and efficacy of epanolol versus nifedipine in patients with stable angina pectoris. 257 83

A clinical study was carried out in 20 patients in coronary angiography to compare two low-osmolar contrast media, sodium-meglumine ioxaglate and iopromide. Ten patients presented a stage III coronary disease and the other ten had a stage IV coronary disease. In the latter group, 70% of the patients received sodium-meglumine ioxaglate and 30% were given iopromide. None of the patients given iopromide had a previous history of allergic-like reactions to contrast media as opposed to the sodium-meglumine ioxaglate group where two patients had a previous hypersensitivity reaction to contrast agents. In spite of these adverse conditions in the sodium-meglumine ioxaglate group, no significant difference was found between both preparations as to overall tolerability. The following side effects were observed: slight nausea and wheezing in a patient given sodium-meglumine ioxaglate; medium intense nausea, vomiting and headache in a patient administered iopromide; one case of angina pectoris occurring 8 minutes post-injection of iopromide. Similarly, no significant difference in overall cardiac tolerability could be found between the two contrast media, although sodium-meglumine ioxaglate would tend to be better tolerated in terms of heart rate and contractility. Radiographic efficacy was considered to be equivalent for both contrast agents though the test solutions had different iodine concentrations. In summary, the two low osmolar contrast media proved well tolerated and showed satisfactory diagnostic efficacy in this population at high cardiovascular risk.
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PMID:Comparison of sodium-meglumine ioxaglate and iopromide in coronary angiography. 266 84


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