Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Five placebo-controlled, double-blind, multicenter, parallel-design studies were performed to evaluate the antianginal and anti-ischemic characteristics of the novel T-channel-selective calcium antagonist, mibefradil, in the treatment of patients with chronic stable angina pectoris. Of the 5 studies, 2 were monotherapy dose-finding trials and 3 were conducted in patients receiving background antianginal therapy: either beta blockers (2 studies) or long-acting nitrates (1 study). A total of 865 patients were randomized to 1 of 4 mibefradil dose groups (25, 50, 100, and 150 mg; n = 565) and placebo (n = 300). The antianginal and anti-ischemic effects of mibefradil were assessed across all 5 studies by evaluating exercise tolerance test variables, weekly number of anginal attacks and short-acting nitroglycerin consumption, and in both dose-finding studies, the number and total duration of silent ischemic episodes (48-hour Holter monitoring). A statistically significant increase in exercise duration was achieved in 3 of 5 studies with the 50-mg dose of mibefradil and in 3 of 3 studies with the 100-mg dose of the compound over the effects observed in the placebo groups. A significant delay in time to onset of ischemia during exercise was induced in all studies with the 50- and 100-mg doses of mibefradil. The 25-mg dose of mibefradil was not significantly better than placebo, and the effects of the 150-mg dose of the compound were similar to those observed with the 100-mg dose. Across all studies, a dose-related decrease was observed in the number of weekly anginal attacks and in weekly nitroglycerin consumption. Similarly, a significant dose-related decrease in the number and duration of silent ischemic episodes was observed during Holter monitoring for 48 hours in the 2 dose-finding studies. The antianginal and anti-ischemic effects were associated with a dose-related decrease in heart rate and double product both at rest and at exercise termination. Treatment with the 50- and 100-mg doses of mibefradil was found to be well tolerated and safe compared with placebo, a finding that held true for patients on chronic beta-blocker or long-acting nitrate therapy. Taken together, these studies indicate that mibefradil is an effective and well-tolerated once-daily treatment for chronic stable angina pectoris at doses of 50 and 100 mg, which are the lowest and highest effective doses of the compound, respectively.
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PMID:Antianginal and anti-ischemic effects of mibefradil in the treatment of patients with chronic stable angina pectoris. 928 50

The ability of mibefradil, a new T-channel-selective calcium antagonist, to improve exercise tolerance and silent ischemic parameters in patients with chronic stable angina was compared in 3 separate trials with 2 other commonly used calcium antagonists: diltiazem SR (120 mg/twice daily) and amlodipine (10 mg/day). Compared with amlodipine, mibefradil 100 mg given once daily over a 3-week period resulted in a statistically significantly larger increase from baseline in total exercise tolerance test (ETT) duration (treatment difference of 40.9 sec, p = 0.04), time to onset of angina (treatment difference 61.2 sec, p < 0.001), and time to onset of ischemia (treatment difference of 54.4 sec, p = 0.004). The decrease in weekly anginal episodes was 58% with mibefradil versus 19% with amlodipine, and the reduction in nitroglycerin consumption was 58% with mibefradil versus a 10% increase with amlodipine. The decrease in the number of silent ischemic episodes detected by a 48-hour Holter recording was significantly larger (p = 0.03) with mibefradil 100 mg (88%) compared with amlodipine 10 mg (38%). Similarly, a larger decrease in the duration of silent ischemia was observed with mibefradil (69%) compared with that seen with amlodipine (38%). The preliminary results of a second trial comparing mibefradil with amlodipine were consistent with the first demonstrating that the improvement for all 3 ETT parameters was larger for mibefradil (ETT duration: 55.2 sec; delay in onset angina: 74.2 sec; time to onset of ischemia: 63.6 sec), but in this trial the treatment differences did not reach statistical significance. In the trial comparing mibefradil (100 mg once daily) with diltiazem SR (120 mg twice daily), both compounds had equivalent effects on all ETT parameters tested. Mibefradil produced a 21% increase in exercise duration compared with a 20% increase with diltiazem. Although mibefradil yielded larger increases in the time to onset of angina and the time to onset of 1-mm ST-segment depression (42% and 38%, respectively) than did diltiazem (34% and 25%, respectively), the treatment differences did not reach statistical significance. Both mibefradil and diltiazem SR were associated with at least a 70% reduction from baseline in anginal frequency and nitroglycerin consumption. Mibefradil-treated patients showed greater decreases in heart rate and the rate-pressure product at each stage of the ETT than patients treated with amlodipine or diltiazem SR. All 3 drugs were well tolerated. However, compared with mibefradil, amlodipine and diltiazem SR produced a higher incidence of leg edema. In conclusion, the effectiveness of mibefradil in improving all 3 ETT parameters was greater than that of amlodipine and equivalent to that of diltiazem SR. Moreover, mibefradil provided greater reductions in the heart rate and cardiac workload than did the other 2 drugs.
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PMID:Mibefradil in the treatment of chronic stable angina pectoris: comparative studies with other calcium antagonists. 928 52

One of the most difficult problems related to coronary artery disease is the detection and eventual treatment of silent myocardial ischemia (SMI). After defining the concept of SMI and total ischemia burden, the author approaches the pathophysiology of myocardial ischemia and focuses on the ischemic cascade. Concerning the detection of SMI the importance of exercise testing and Holter ECG is stressed. Following the classification of SMI proposed by P. F. Cohn, the author analyzes SMI type III with particular interest. He refers the prevalence of SMI in patients suffering from chronic stable angina, and focuses on the prognostic importance of SMI. Afterwards, the problem of treatment and prognostic implications is approached. The paper ends with mention of the results of the most important clinical trials in this field: CASIS, CAPE, TIBBS, ASIST, ACIP, TIBET.
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PMID:[Angina pectoris. Silent ischemia]. 934 Oct 23

The optimal treatment of patients with single-vessel coronary artery disease (CAD) and chronic stable angina is controversial. Therapeutic options include medical therapy with pharmacologic agents and/or coronary revascularization via surgery (coronary artery bypass grafting [CABG]), percutaneous transluminal coronary angioplasty (PTCA), and/or other transcatheter techniques. Early studies found no difference in survival between medical and surgical treatment of patients with single-vessel disease and chronic stable angina. Although PTCA has been shown to improve symptoms and quality of life in patients with single-vessel disease and severe symptoms, improvement in survival and prevention of future events are not established and multiple PTCA procedures or subsequent surgical treatment may be necessary. Medical therapy may be preferred in patients with mild or no symptoms. In patients with chronic stable angina, PTCA practice may not be consistent with current guidelines, particularly obtaining laboratory evidence of ischemia before the procedure. Stenoses that may lead to future coronary events cannot be accurately identified by angiography without evidence of ischemia or symptoms. Currently available comparative studies of patients with CAD do not reflect the impact of stent procedures and aggressive lipid lowering. Therefore, diagnostic and treatment options should be individualized in patients with single-vessel disease and chronic stable angina, and additional randomized trials are necessary to determine the optimal management of these patients.
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PMID:Pathophysiology and treatment of single-vessel coronary artery disease. 937 36

Mibefradil is the first of a new class of calcium antagonists with a unique structure and pharmacology. Its novel mechanism of action is characterized by L-type and selective T-type calcium channel blockade. Mibefradil is selective for smooth muscle over cardiac muscle and selectively dilates the coronary vasculature over the peripheral vasculature. In animal studies, mibefradil increases coronary blood flow during induced ischemia. In addition, in vitro studies demonstrated that mibefradil decreases smooth muscle proliferation in response to vascular injury. The most intriguing effects of mibefradil include a lack of negative inotropy and reflex tachycardia, as well as inhibition of pathologic hypertrophy and remodeling in response to vascular injury. In clinical trials, mibefradil (100 mg) was more effective than diltiazem dual-release capsules (360 mg) and as effective as amlodipine (10 mg) in treating mild-to-moderate hypertension; mibefradil (100 mg) also resulted in a greater reduction in sitting diastolic blood pressure than did nifedipine GITS (60 mg) in patients with moderate-to-severe hypertension. In patients with chronic stable angina, mibefradil (100 mg) was as effective as diltiazem SR capsules (120 mg) twice daily and more effective than amlodipine (10 mg) in improving exercise tolerance and reducing ischemic episodes. Mibefradil improved survival in a rat model of heart failure as effectively as the angiotensin-converting enzyme (ACE) inhibitor, cilazapril. The apparent lack of negative inotropic activity and neurohormonal activity with mibefradil, as well as its favorable effects on cardiac remodeling in experimental models, suggest that this agent may be beneficial in congestive heart failure. This hypothesis is being tested in the ongoing Mortality Assessment in Congestive Heart Failure (MACH-1) trial.
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PMID:Mibefradil: a selective T-type calcium antagonist. 937 39

Recently, there has been some controversy concerning calcium antagonists, suggesting the need for further debate on this heterogeneous class of drugs. Three chemical families, dihydropyridines (DHP), phenylalkylamines (verapamil) and benzothiazepines (diltiazem) bind to the type L receptors of the calcium channels with different binding, modulation and tissue selectivity characteristics. DHP are selective for type L receptors and block the extracellular portion of the channel leading to vigorous vasodilatation and little or no cardiodepressive effect. Diltiazem and verapamil also interfere with type T channel receptors. These drugs have a cardiodepressive and a bradycardia effect. Verapamil blocks the intracellular portion of the calcium channel at the site where part of the catecholamine effect occurs, leading to less reflex sympathetic activation than with other calcium antagonists (namely DHP). Deleterious sympathetic stimulation is proportional to the intensity and degree of rapid onset of arterial vasodilatation and is attenuated with slow-release formulations. Calcium antagonists in general have an anti-angina effect but high-dose short-acting DHP can cause excessive vasodilatator leading to subsequent ischemia. In chronic stable angina, slow-release verapamil has been shown to have a preventive clinical effect comparable to that of beta blockers. Slow-release nifedipine is effective and safe but must be associated with betablockers. In unstable angina, only those calcium antagonists with a bradycardia effect appear to have an effect similar to beta blockers. Beta blockers are nevertheless to be preferred in these patients (excepting Prinzmetal angina) until results of convincing clinical studies are available. After the initial phase of myocardial infarction, again only calcium antagonists with a bradycardia effect have been shown to have a beneficial effect, in patients without cardiac failure: diltiazem in infarction without Q-wave and verapamil in all infarctions, in case of residual ischemia to reduce the risk of recurrence.
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PMID:[Calcium antagonists in ischemic heart disease]. 941 Oct 6

MIBEFRADIL IN THE TREATMENT OF HYPERTENSION: The antihypertensive efficacy of mibefradil, a new selective transient (T)-channel calcium antagonist, was studied in eight randomized, double-blind, parallel-design trials: four placebo-controlled and four active drug-controlled versus other calcium antagonists. These studies established that at doses of 50 and 100 mg, mibefradil is an effective, well tolerated and safe treatment for high blood pressure. The antihypertensive effect of mibefradil was achieved gradually, with the full activity reached within 1-2 weeks. The decrease in arterial pressure was smooth and sustained over the entire 24-h dosing interval. The antihypertensive action was associated with a dose-related reduction in the heart rate. The efficacy results were similar across all demographic subpopulations studied, including high-risk groups: individuals with chronic renal failure; the elderly; and hydrochlorothiazide-treated patients. In studies comparing mibefradil with other calcium antagonists at their recommended doses, 100 mg mibefradil demonstrated significantly better antihypertensive efficacy than controlled-dose (CD) diltiazem at 360 mg or slow release (SR) nifedipine at 40 mg twice a day, and similar efficacy to that of 10 mg amlodipine or 60 mg nifedipine gastrointestinal therapeutic system (GITS). MIBEFRADIL IN THE TREATMENT OF ANGINA PECTORIS: The efficacy, safety, and tolerability of 50 and 100 mg mibefradil in the treatment of chronic stable angina pectoris was tested in six randomized parallel-design studies. Significant increases in exercise duration and a significant delay in the onset of ischemia during exercise were found in most studies with the 50-mg dose and in all studies with the 100-mg dose. Weekly anginal attacks and nitroglycerine consumption decreased significantly in a dose-related manner and, similarly, a significant dose-related decrease in the number and duration of silent ischemic episodes was observed on 48-h Holter monitoring. In the two studies with active drug controls, 100 mg mibefradil was significantly better than 10 mg amlodipine and equivalent to 120 mg diltiazem SR twice a day in improving anti-anginal and anti-ischemic parameters. In all studies, mibefradil treatment produced a dose-related reduction in the heart rate and the rate-pressure product at rest and at the end of exercise, and the magnitude of these decreases was larger than that observed with the other two calcium antagonists. SAFETY AND TOLERABILITY: An integrated analysis of combined data on the safety and tolerability of mibefradil from studies on hypertension and angina pectoris confirmed that mibefradil and diltiazem were equally well tolerated, but the incidence of leg edema was clearly higher in patients treated with the dihydropyridine calcium antagonists amlodipine and nifedipine.
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PMID:Differential properties of mibefradil in hypertension and angina. 948 14

Pharmacotherapy with nitrates, beta-blockers, and calcium antagonists is the cornerstone of management of patients with chronic stable angina pectoris. While these agents are all effective, their use may be limited by pharmacologic tolerance, side effects, and drug interactions. Mibefradil is a recently developed calcium antagonist with a unique chemical structure, pharmacologic profile, and mode of action. Unlike all previously available calcium antagonists, mibefradil acts primarily by selective blockade of T-type calcium channels, rather than L-type channels, at clinically relevant concentrations. It has been evaluated as a treatment for angina in placebo-controlled and active-controlled clinical trials. Treatment with 50 mg mibefradil resulted in a significant improvement in exercise tolerance test duration in three of the five placebo-controlled trials, and a significant improvement in time to onset of angina in two of the five trials. Time to onset of ischemia as evaluated by 0.1 mV ST-segment depression was increased in all five placebo-controlled trials. Treatment with 100 mg mibefradil resulted in significant improvement in all three exercise tolerance test parameters in all studies. Mibefradil further improved exercise tolerance test duration and other efficacy parameters when administered concomitantly to patients on background beta-blocker or nitrate therapy. In addition, treatment with mibefradil was associated with a dose-dependent decrease in heart rate, double product, frequency of anginal attacks, nitroglycerin consumption, and both frequency and duration of silent ischemic episodes. In comparative trials, 100 mg mibefradil once daily was superior in efficacy to 10 mg amlodipine once daily and was at least equivalent to diltiazem in both efficacy and tolerability. Mibefradil was safe and well tolerated in all studies.
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PMID:Mibefradil, a T-type channel-selective calcium antagonist: clinical trials in chronic stable angina pectoris. 960 73

The Circadian Anti-ischemia Program in Europe (CAPE) trial was a large, 10-week, double-blind study of the antiischemic effects of the third-generation calcium antagonist, amlodipine, in patients with chronic stable angina. The study showed that, compared with the addition of placebo to conventional medical therapy (if any), the addition of amlodipine significantly reduced the total ischemic burden. Both symptomatic and asymptomatic ischemic events were reduced, over 24 hours, with no change in the heart rate profile. The next logical step is to compare amlodipine with other agents, as monotherapy and in combination therapy, which is the basis for the CAPE II trial. This European multicenter project will recruit patients with coronary artery disease and chronic stable angina in order to compare the efficacy of the intrinsically long-acting amlodipine with an artificially extended-release formulation of diltiazem, a calcium antagonist with a short plasma half-life. The impact of these agents will also be compared during irregular dosing periods. An agent with an intrinsically long half-life, such as amlodipine, may maintain better clinical efficacy than a short-acting drug with a prolonged delivery system in these circumstances. The CAPE II trial will investigate whether this results in improved management of the circadian pattern of transient myocardial ischemia. In addition, basic therapy will be augmented by the addition of a beta-blocker to amlodipine and the addition of a nitrate to diltiazem to evaluate which of these frequently prescribed treatment approaches results in optimal ischemia suppression. Both the subjective endpoints of angina and patient well-being, as well as the objective measures of myocardial ischemia in exercise testing and ambulatory electrocardiography (ECG) monitoring, will be employed. Answers to these issues will help to define the optimal medical approach to ischemia suppression in patients with coronary artery disease and will complement the findings from large-scale prognosis trials currently being performed.
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PMID:Amlodipine versus diltiazem CR in the reduction of the total ischemic burden: the Circadian Anti-Ischemia Program in Europe (CAPE) II trial--clinical rationale and methodology. 980 53

This multicenter, randomized, double-blind, parallel group, placebo lead-in, placebo-controlled study compared the antianginal and anti-ischemic effects of once-daily bedtime dosing of controlled-onset extended-release (COER-24) verapamil to a once-daily morning dosing of amlodipine +/- atenolol in patients with chronic stable angina. A total of 551 patients with exercise-induced myocardial ischemia and evidence of coronary artery disease were randomized to a 4-week, forced-dose titration treatment period with (1) COER-24 verapamil 240 mg titrated to 480 mg at bedtime (n = 173), (2) amlodipine 5 mg titrated to 10 mg/day (n = 149), (3) amlodipine 5 mg (titrated to 10 mg) plus atenolol 50 mg/day in the A.M. (n = 154), or (4) placebo (n = 75). Treadmill exercise tolerance testing (standard Bruce protocol), and 48-hour ambulatory electrocardiographic (Holter) monitoring were performed at the end of placebo lead-in and double-blind treatment. Each active treatment significantly improved symptom-limited exercise duration and time to moderate angina (p < or = 0.01 vs placebo). For patients with baseline ischemia, amlodipine resulted in a statistically significant increase in total duration of ischemic episodes compared with placebo, whereas COER-24 verapamil and amlodipine plus atenolol resulted in statistically significant decreases compared with placebo and amlodipine. Heart rate at onset of ischemic episodes and ST product were also significantly increased with amlodipine (p < 0.05) compared with either COER-24 or amlodipine plus atenolol. COER-24 and amlodipine alone or in combination with atenolol improved exercise capacity in patients with angina pectoris. COER-24 verapamil monotherapy or amlodipine plus atenolol combination therapy were more effective than amlodipine monotherapy in decreasing ambulatory myocardial ischemia, especially during the hours of 6 A.M. to 12 noon.
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PMID:Comparison of controlled-onset, extended-release verapamil with amlodipine and amlodipine plus atenolol on exercise performance and ambulatory ischemia in patients with chronic stable angina pectoris. 1007 52


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