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Biomedical subjects

N Bittar

Publications and source records attributed to N Bittar.

At least 19 recordsLinked to original sources
PubMed1998

Additional antianginal and anti-ischemic efficacy of mibefradil in patients concomitantly treated with long-acting nitrates for chronic stable angina pectoris.

BACKGROUND: Mibefradil, a newly approved antihypertensive and antianginal drug, is the first member of a new class of calcium antagonists (CAs), the tetralol derivatives, that selectively blocks T-type Ca2+ channels in contrast to classical CAs which, at therapeutic concentrations, block only L-type Ca2+ channels. Since patients with chronic stable angina pectoris typically may be treated with the combination of a long-acting nitrate and a CA, the additive efficacy and safety of mibefradil in combination with nitrate therapy needs to be determined. HYPOTHESIS: This study was designed to assess the efficacy, tolerability, and safety of mibefradil when added to long-acting nitrate therapy in patients with chronic stable angina pectoris. METHODS: Following a 1-week placebo run-in period, patients were randomized to receive either mibefradil 50 mg (n = 96) or placebo (n = 93) once daily in addition to their nitrate therapy. After 2 weeks of active treatment, patients receiving the mibefradil were force titrated to 150 mg once daily for an additional 2 weeks. Exercise tolerance tests (ETTs) were performed at the end of Weeks 2 and 4; patients also maintained an anginal diary during the 4-week treatment period. RESULTS: After 2 weeks of treatment with 50 mg mibefradil (within the current recommended dose range), a statistically significant but modest increase in total exercise duration was observed (treatment effect 16.4 s, p = 0.04). Similarly, there was a significant increase in time to onset of ischemia (treatment effect 26 s, p = 0.008). The adverse event profile of the 50 mg dose was indistinguishable from placebo, indicating that this dose was extremely well tolerated. At Week 4, the mibefradil-treated patients were taking 150 mg, which is above the current recommended dose range. The increase in total exercise duration was larger for the mibefradil 150 mg group than for the placebo group. For the intent-to-treat population, this difference did not reach statistical significance, whereas in the standard population it did (treatment effect 21 s, p = 0.05). The other two ETT variables, time to onset of angina and time to onset of 1 mm ST-segment depression, demonstrated significantly greater effect with mibefradil 150 mg (treatment effects 40 s, p = 0.002, and 55 s, p < 0.001, respectively, for the intent-to-treat population). Mibefradil 150 mg was associated with more adverse events than placebo, specifically, dizziness, leg edema, and postural hypotension. CONCLUSIONS: This study demonstrates that mibefradil 50 mg once daily in the setting of the background long-acting nitrate therapy produces additive antianginal and anti-ischemic effects and is extremely well tolerated.

Adolescent↗
PubMed1997

Clinical characteristics and management of acute stroke in patients with atrial fibrillation admitted to US university hospitals.

UNLABELLED: The optimal evaluation and management of patients with atrial fibrillation who suffer an acute ischemic stroke remains controversial. METHODS: Medical records of 171 consecutive patients with atrial fibrillation and acute stroke at six U.S. university hospitals were reviewed. Data collected included the use of antithrombotic therapy, brain and cardiac imaging, bleeding complications, stroke risk factors, and contraindications to anticoagulation. RESULTS: Mean age was 75.4 years. Cardiovascular risk factors associated with increased stroke risk were present in 87%; 35% had at least one contraindication to anticoagulation. Half of the patients with stroke risk factors and no contraindications to anticoagulation were not receiving any antithrombotic therapy at the time of admission. Of the 22 patients who were treated with warfarin, and had INR values on admission, 16 had levels of < 2.0; only six had INR values between 2.0 and 3.0. Transthoracic echocardiography was performed in 107 patients (63%); intracardiac thrombi were visualized in only 5%. Initial brain imaging revealed hemorrhagic transformation in nine. Heparin was used in 93 patients (54%), usually within 48 hours of stroke onset. Patients who received delayed heparin typically did not have repeat brain imaging prior to starting heparin. One patient had a delayed symptomatic cerebral hemorrhage. Of the survivors, 47% were discharged and treated with warfarin (or warfarin plus aspirin), 28% with ASA, 7% with other antithrombotic therapies, and 18% with no antithrombotic therapy. CONCLUSION: Antithrombotic therapy was underutilized and inadequately monitored in atrial fibrillation patients prior to stroke onset. After hospital admission, a wide range of diagnostic and management strategies, which often did not follow current recommendations, were employed.

Acute Disease↗
PubMed1996

Status of antithrombotic therapy for patients with atrial fibrillation in university hospitals.

BACKGROUND: The risk of stroke in patients with atrial fibrillation can be significantly reduced with antithrombotic therapy. Despite this, many physicians remain hesitant to prescribe warfarin sodium or aspirin therapy for patients with atrial fibrillation. OBJECTIVE: To assess the use of antithrombotic therapy in patients with atrial fibrillation at 6 academic hospitals in the United States. METHODS: Records were reviewed from consecutive hospital admissions of 309 patients with atrial fibrillation at 6 members of the University Health System Consortium, Oak Brook, III, which is a member driven alliance of 70 academic health centers in the United States. Risk factors for stroke, contraindications to anticoagulant therapy, and use of antithrombotic therapy at admission and discharge were recorded. RESULTS: The mean age of patients was 71.6 years, 54% had chronic, 22% paroxysmal, and 24% new-onset atrial fibrillation. Eighty-two percent of the patients had cardiovascular risk factors that have been associated with increased risk of stroke. At least 1 relative contraindication to anticoagulant therapy was present in 44%. At the time of admission. 32% of the patients with previously diagnosed atrial fibrillation (n = 235) were receiving warfarin (or warfarin plus aspirin), 31% were receiving aspirin alone, and 36% were receiving no antithrombotic therapy. At discharge (n = 230), 41% of these patients were taking warfarin (or warfarin plus aspirin) and 36% were taking aspirin. Forty-four percent of the patients with risk factors for stroke and no contraindications to anticoagulation (n = 134) were discharged on a regimen of warfarin (or warfarin plus aspirin), 34% were discharged on a regimen of aspirin, and 22% received no antithrombotic therapy. CONCLUSIONS: About half of the patients with atrial fibrillation admitted to these academic hospitals had clinical risk factors that are associated with increased risk of stroke and no contraindications to anticoagulation. Antithrombotic therapy was underused in these patients.

Academic Medical Centers↗
PubMed1996

Pharmacologic profile of survivors of acute myocardial infarction at United States academic hospitals.

Optimal drug therapy for patients with acute myocardial infarction (AMI) is well described in the medical literature. However, data on the actual pharmacologic management of patients surviving AMI at academic hospitals is unavailable. The purpose of this study was to document treatment profiles in 500 patients surviving AMI at 12 academic hospitals in the United States. These profiles were compared with established guidelines and were evaluated for trends. Overall, thrombolytics (streptokinase > or = tissue-type plasminogen activator) were administered in 29% of the patients, with a greater proportion of patients receiving beta-blockers than calcium channel antagonists in the initial 72 hours (61% vs 40%; p < 0.005) and at discharge (51% vs 35%; p < 0.005). Further, women were less likely than men to receive thrombolytic therapy (odds ratio [OR] = 0.61; confidence interval [CI], 0.54 to 0.69) or beta-blocker therapy within the first 72 hours (OR = 0.61; CI, 0.55 to 0.67) or at hospital discharge (OR = 0.53; CI, 0.48 to 0.58). Overall, improvements could still be made in the number of patients who receive thrombolytic and acute and chronic beta-blocker therapies after AMI, particularly in women. Changes in treatment profiles may be a reflection of the publication of large clinical trials.

Adrenergic beta-Antagonists↗
PubMed1995

Maintaining long-term control of blood pressure: the role of improved compliance.

Mild-to-moderate essential hypertension is a major risk factor for stroke and cardiovascular mortality and morbidity. Morbidity can be reduced significantly by lowering high blood pressure, and with the effective antihypertensive drugs now available, it is ever more important to identify and treat the estimated 50 to 60 million hypertensive persons in the United States. Yet a high percentage of persons being treated stop taking their medication and refuse to comply with their therapeutic regimen. Many problems relate to maintaining long-term therapy in the hypertensive population. They include the cost of medication, a lack of written instructions, unclear instructions, noninvolvement of the patient in designing the treatment plan, lack of patient education about the disease, side effects, and inconvenient dosing schedules. Numerous studies have found that compliance increases as drug-dosage frequency decreases, as with the use of once-daily or sustained-release drug preparations. Other contributors to compliance include prescription-refill reminders, appointment reminders, simple written instructions about drug use, and patient education about the need for treatment and the consequences of noncompliance. Many classes of antihypertensive drugs are available, and more are in development. With such an extensive armamentarium available, all patients, regardless of coexisting medical conditions, should be able to be given effective, individualized antihypertensive therapy.

Blood Pressure↗
PubMed1995

Antianginal and antiischemic efficacy of monotherapy extended-release nisoldipine (Coat Core) in chronic stable angina.

A double-blind, randomized, placebo-controlled study was conducted to test the peak and trough antianginal and antiischemic monotherapy efficacy and safety of a new extended-release formulation of nisoldipine (nisoldipine Coat Core [Bayer Corporation], 20 mg, 40 mg, and 60 mg once daily compared to placebo). Study patients had a history of chronic, stable angina pectoris, exercise-induced angina in association with ST segment depression, and exercise test reproducibility. Of the 483 patients enrolled in the study, results were valid for safety analysis for 312 and for efficacy analysis for 284. There was a statistically significant improvement in total exercise time at both peak and trough for patients taking 20 mg and 60 mg of nisoldipine compared with patients taking placebo, but the group taking 60 mg was not better than the group taking 20 mg (33.9 and 33.7 seconds, respectively, at trough). The results were similar for the secondary endpoints (time to onset of angina and time to 1 mm ST segment depression). No correlation was evident between plasma nisoldipine levels and total exercise duration. Headache and peripheral edema were the most frequently reported adverse events and were dose related. There were no discontinuations due to adverse events in patients randomized to the 20-mg nisoldipine group. No deaths occurred while patients were receiving active nisoldipine therapy. Therapy with this extended-release formulation of nisoldipine is an effective once-daily treatment for chronic stable angina pectoris. It represents one of the few dihydropyridine calcium channel antagonists that has shown efficacy when administered as monotherapy to patients with angina.

Adult↗
PubMed1994

Dose-response evaluation of once-daily therapy with a new formulation of diltiazem for stable angina pectoris. Diltiazem CD Study Group.

Diltiazem hydrochloride in a once-daily capsule formulation (DCD) has recently been approved in the United States for the treatment of mild to moderate hypertension and chronic stable angina pectoris. This trial evaluated the dose response of DCD in patients with chronic stable angina pectoris. In a multicenter, randomized, double-blind, parallel-design trial, the effects and tolerability of once-daily therapy with placebo or DCD (60, 120, 240, 360, or 480 mg) were evaluated 24 hours after dosing, following 3 weeks of therapy in 227 patients with reproducible stable exertional angina pectoris. A significant linear dose trend (p = 0.004) was present across the 6 treatment groups for the primary end point--time to exercise termination at 24 hours after dosing--using a standard Bruce treadmill exercise test. A significant linear dose trend was also seen for time to 1 mm ST-segment depression at 24 hours after dosing. Similar effects on exercise parameters were also seen at 4 hours after dosing. A linear dose trend (p = 0.04) was noted relative to the overall anginal attacks during daily activities and for anginal attacks during exercise (p = 0.02). Overall frequency of treatment-related adverse effects was dose-related and occurred in 24.4% and 17.5% of patients treated with DCD and placebo, respectively. At a dose up to 240 mg/day, improvement in exercise tolerance was achieved without an associated increase in the rate of treatment-related adverse events compared with placebo.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Antianginal and anti-ischemic efficacy of immediate-release nisoldipine in chronic stable angina pectoris.

A double-blind, randomized, placebo-controlled, crossover study tested peak and trough efficacy of immediate-release nisoldipine (20 mg twice daily) added to existent beta-adrenergic blocking therapy. Patients were randomized with a history of chronic stable angina, while receiving a stable regimen of a beta-blocking agent, with exercise test-induced angina in association with 1 mm horizontal or downsloping ST-segment depression and exercise test reproducibility of +/- 15%. Ambulatory electrocardiographic monitoring (48-hour) was performed at 3 of 5 centers (44 patients). Efficacy was achieved in 53 patients (26 taking immediate-release nisoldipine/placebo in sequence and 27 taking placebo/immediate-release nisoldipine in sequence). Total exercise time increased compared with placebo at peak, but only a trend was seen at trough. Time to 1 mm ST-segment depression at peak and trough and ambulatory electrocardiographic parameters were also improved. Adverse effects were mild. This trial confirms that immediate-release nisoldipine when added to existent beta-blocker therapy is an active antianginal and anti-ischemic agent, but that the immediate-release formulation loses its antianginal effect at the end of its dosing interval (9 to 14 hours). This drug is therefore being examined in a new extended-release formulation (Coat-Core).

Adrenergic beta-Antagonists↗
PubMed1994

Betaxolol in the treatment of stable angina pectoris.

Betaxolol, a long-acting cardioselective beta-blocker, was tested alone and in combination with long-acting nitrates in a multicenter, double-blind, parallel, placebo-controlled study of 3 weeks duration in patients with stable angina pectoris. All patients underwent exercise tolerance tests (ETTs) using Bruce's protocol. During the 3- to 4-week single-blind placebo baseline phase, all other drugs except sublingual nitroglycerin and long-acting nitrates were withdrawn. Those patients (n = 115) whose time to onset of moderate angina was between 2.5 and 7.5 min and was within +/- 15% in 2 consecutive ETTs were randomized to betaxolol 20 mg/day (n = 54) or placebo (n = 53). Betaxolol, compared to placebo, increased time to onset of angina, time to 1 mm S-T segment depression, and total exercise time and decreased the double product, weekly anginal attacks, and sublingual nitroglycerin consumption (p < 0.01). Our results indicate that betaxolol given in fixed 20-mg daily doses was efficacious in stable angina pectoris and its combination with long-acting nitrates potentiated its effect.

Angina Pectoris↗
PubMed1993

Efficacy and safety of extended-release isosorbide mononitrate for stable effort angina pectoris.

The efficacy and safety of extended-release isosorbide mononitrate tablets were evaluated in patients with stable effort angina. In a double-blind study, 313 patients with stable effort-induced angina were randomized to receive placebo or extended-release isosorbide mononitrate: 30, 60, 120 or 240 mg once daily in the morning. Serial exercise testing was performed using the standard Bruce treadmill protocol on days 1, 7, 14, 28 and 42 immediately before morning drug administration, and 4 and 12 hours after administration. After initial dosing, all groups that received extended-release isosorbide mononitrate had significant (p < 0.01) increases in mean total exercise time of approximately 30 to 50 seconds in relation to placebo 4 and 12 hours after administration. On day 42, mean changes from baseline in total exercise time of patients who received 120 or 240 mg of extended-release isosorbide mononitrate exceeded placebo by approximately 50 to 60 seconds 4 hours after dosing (p < 0.01), and by 30 to 35 seconds 12 hours after dosing (p < or = 0.05). No significant difference was detected between responses to extended-release isosorbide mononitrate and placebo 24 hours after administration (i.e., immediately before the next dose). Thus, there was neither significant activity nor demonstrable rebound of effort-induced angina (zero-hour effect) at the end of the dosing interval. Transient headache was the most prevalent adverse experience. Extended-release isosorbide mononitrate (120 and 240 mg administered orally once daily) significantly prolonged exercise time to development of moderate effort-induced angina 4 and 12 hours after dosing during long-term therapy, without development of nitrate tolerance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Effects of 8:00 a.m. and 2:00 p.m. doses of isosorbide-5-mononitrate during twice-daily therapy in stable angina pectoris.

"Trough" plasma concentrations of isosorbide-5-mononitrate (IS-5-MN), an active metabolite of isosorbide dinitrate, of less than 95 ng/ml are considered necessary to prevent development of tolerance to isosorbide dinitrate and IS-5-MN. In a double-blind, crossover, placebo-controlled study, the effects of IS-5-MN during twice daily eccentric therapy were evaluated in 18 patients with reproducible exercise-induced angina who were nitrate responders. In a random order, patients received either placebo or IS-5-MN (20 mg) at 8 a.m. and 2 p.m. for 1 week each. Average trough plasma IS-5-MN concentrations before the 8 a.m. and 2 p.m. doses were 67 and 226 ng/ml, respectively, and increased to 382 and 488 ng/ml 2 hours after the 8 a.m. and 2 p.m. doses, respectively. Despite a more than threefold higher trough plasma IS-5-MN concentration before the 2 p.m. dose than before the 8 a.m. dose, the increase in exercise duration 2 hours after the doses was similar (1.21 minutes [21%] after 8 a.m. dose, and 1.08 minutes [19%] after 2 p.m. dose). These increases in exercise duration after IS-5-MN were significantly (p less than 0.01) greater than those observed after placebo (0.17 minutes [3%] after 8 a.m. dose, and -0.05 minute [-0.5%] after 2 p.m. dose). Reduction in standing systolic blood pressure at 2 hours after the doses was also nearly identical after the 8 a.m. and 2 p.m. doses of IS-5-MN (21 [15%] and 19 [14%] mm Hg, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Double-blind, dose-response, placebo-controlled multicenter study of nisoldipine. A new second-generation calcium channel blocker in angina pectoris.

BACKGROUND: Nisoldipine is a potent 1:4 dihydropyridine calcium channel antagonist, and doses of 5 or 10 mg administered either once or twice daily have been claimed to exert antianginal effects. There is, however, little information regarding the dose-response relation and whether the drug exerts any consistent effects throughout the dosing interval. In this placebo-controlled, parallel-design study, the dose-response relation of monotherapy with nisoldipine administered twice daily was studied in patients with stable angina pectoris. METHODS AND RESULTS: Two hundred thirty-one patients received single-blind placebo for 2 weeks; of these, 185 patients who reproducibly stopped treadmill exercise because of angina of moderate severity and had greater than or equal to 1 mm ST segment depression during exercise and experienced an average of three episodes of anginal attacks per week were randomized in a double-blind manner to one of the four treatment groups: placebo (n = 48), nisoldipine 2.5 mg (n = 47), nisoldipine 5 mg (n = 44), or nisoldipine 10 mg (n = 46). Nisoldipine or placebo was administered twice daily for 4 weeks and symptom-limited exercise tests were repeated at 2 and 10-14 hours after the double-blind medication. One hundred sixty-eight patients completed the study and 181 patients were valid for efficacy analysis. Compared with double-blind placebo, there were marginally significant trends toward increases for time to onset of angina for the 10-mg-b.i.d. group (83 versus 108 seconds, p = 0.08), time to 1 mm ST segment depression for the 5-mg-b.i.d. group (54 versus 83 seconds, p = 0.08), and total exercise time for the 5- (30 versus 50 seconds, p = 0.10) and 10-mg-b.i.d. (30 versus 58 seconds, p = 0.06) groups at 2 hours after the dose (peak effect) after 4 weeks of therapy. At 10-14 hours after the dose (trough effect), no differences between placebo and any of the nisoldipine doses on any of the exercise parameters were found after 4 weeks of therapy. A subset analysis of patients who stopped exercise within 10 minutes because of angina of moderate severity during single-blind placebo therapy (n = 123) revealed significant increase in total exercise duration and time to 1 mm ST segment depression at 2 hours after the dose in the 5- and 10-mg-b.i.d. dose groups compared with double-blind placebo (p less than 0.04). No significant trough effects, however, were observed even in this subgroup after any of the doses of nisoldipine. The frequency of anginal attacks decreased by 44%, 41%, 30%, and 41% after twice-daily therapy with 2.5 mg, 5 mg, 10 mg nisoldipine, and placebo groups, respectively (p = NS, nisoldipine versus placebo). The incidence of adverse events (minor and major) was 43.8% in the placebo group and 42.6%, 45.5%, and 56.5% in the nisoldipine 2.5-, 5-, and 10-mg-b.i.d. groups, respectively (p = NS compared with placebo). However, four patients developed unstable angina while on nisoldipine therapy (two in the 2.5-mg, one in the 5-mg, and one in the 10-mg-b.i.d. group) and two patients died suddenly in the nisoldipine 10-mg-b.i.d. group. CONCLUSIONS: Monotherapy with 2.5, 5, and 10 mg nisoldipine twice a day was not superior to placebo therapy in treating patients with angina pectoris, and the 10-mg-b.i.d. therapy resulted in a statistically insignificant but clinically important increase in the incidence of serious adverse events.

Adult↗
PubMed1990

Exogenous superoxide dismutase and catalase promote recovery of function in isolated rat heart after regional ischemia and may be transported from capillaries into myocytes.

The effects of infusing superoxide dismutase (SOD) and catalase (CAT) into the coronary circulation were investigated in isolated, working rat hearts prior to and during a 15 minute episode of regional ischemia followed by 30 minutes reperfusion. Aortic output, left ventricular pressure and dP/dT were recorded. Compared to untreated hearts, SOD and CAT significantly improved function during reperfusion, but had no effect during the pre-ischemic or the ischemic period. To investigate possible transport of SOD and CAT into rat myocytes, cryotome sections of isolated, Langendorff perfused rat hearts were exposed to rabbit antibody prepared against the exogenous SOD and CAT. Bound antibody was detected by the indirect-fluorescent antibody test. The interior of myocytes from rat hearts exposed to SOD and CAT bound antibodies prepared against these enzymes, whereas myocytes from rat hearts not exposed to exogenous SOD and CAT only bound the CAT antibodies. This indicates the anti-SOD we prepared is specific for exogenous SOD, and also suggests exogenous SOD can gain access to the cytoplasm of myocytes from the coronary circulation.

Animals↗
PubMed1990

Evidence for transcytosis of exogenous superoxide dismutase and catalase from coronary capillaries into dog myocytes.

Infusion of superoxide dismutase (SOD) and catalase (CAT) into the coronary circulation protects myocardial tissue from free radical injury and improves recovery of myocardial function after a short episode of ischaemia. To investigate the ultrastructure of myocardium treated with SOD and CAT, these enzymes were injected into the left atrium of dogs prior to and during 15 min of regional myocardial ischaemia, allowing 30 min of reperfusion, and then fixing the tissue for electron microscopy. The exogenous SOD + CAT was found to promote recovery of both function and structure in these hearts. In addition, electron dense material was unexpectedly found in vesicles of capillary endothelia, between capillaries and myocyte, and in vesicles within myocytes. This occurred only in hearts treated with SOD and/or CAT, suggesting SOD and CAT was concentrated and transported across the capillary endothelium and into myocytes. The rate of transcytosis, as measured by the number of intra-endothelial vesicles, was increased in tissue subjected to ischaemia and reperfusion in the presence of SOD and CAT. These observations suggest transcytosis of SOD and CAT is an important part of the process by which these enzymes provide protection to myocardium during reperfusion after ischaemia.

Animals↗
PubMed1989

Usefulness of nifedipine for myocardial ischemia and the nifedipine gastrointestinal therapeutic system.

Although conventional treatment of angina pectoris with nifedipine capsules involves frequent daily dosing, a new vehicle for the once-daily delivery of this potent but insoluble calcium channel blocking agent has been developed. With the gastrointestinal therapeutic system (GITS) formulation, constant effective drug levels of nifedipine are delivered for a full 24-hour period. When nifedipine GITS 30, 60 or 90 mg was administered once daily to patients with stable angina pectoris taking beta blockers, clinical effectiveness was demonstrated both by an increase in time to angina and by exercise time compared with placebo. Improvement was noted to be more significant with the higher doses of nifedipine administered once daily. This study indicates that nifedipine GITS provides additional antianginal protection in patients with exercise-induced angina secondary to coronary artery disease who are receiving a fixed dose of beta blocker.

Angina Pectoris↗
PubMed1989

Inhibitors of adenosine catabolism improve recovery of dog myocardium after ischemia.

The effects of inhibitors of adenosine catabolism on contractile function and metabolites were assessed during 15 minutes of ischemia followed by 30 minutes of reperfusion in the open-chest dog heart. As compared to sham treatment, pretreatment with erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA) and dipyridamole (DP) protected contractile function during ischemia, and improved recovery of high energy phosphate content and contractile function during reperfusion following ischemia. Testing EHNA and DP in a free-radical generating system indicated both compounds have some scavenging ability, suggesting the effect of EHNA + DP may not be on adenosine nucleotide metabolism alone. Comparison of end diastolic segment lengths to contractile function indicated the results were not affected by changes in preload resulting from peripheral vasodilation.

Adenine↗
PubMed1989

The efficacy and safety of dilevalol in patients with chronic stable angina pectoris.

This is the first reported large clinical trial of the antianginal and acute ischemic effectiveness and safety of dilevalol (the R, R-isomer of labetalol) in patients with chronic stable angina pectoris. This was a multicenter double blind fixed-dose parallel group placebo controlled trial. Patients with chronic stable angina and positive and reproducible exercise tests (+/- 20%) were included. If randomized, patients entered one of four fixed dose groups (twice a day placebo, 100 mgm, 200 mgm and 400 mgm bid for 2 weeks). Exercise testing was performed at 2 hours (peak) and 12 hours (trough) postdosing. This was followed by a 2-week once-a-day dosing regimen in which patients received the same total daily dose as the prior 2 weeks, with the full dose in the morning and a matched placebo in the evening. Exercise testing was performed at 2 hours (peak) and 24 hours (trough) postdosing. Anginal frequency and NTG consumption were significantly reduced, and equally so, by qd and bid regimens. The time of exercise to the onset of angina increased and the proportion of patients terminating exercise because of moderate angina decreased in a dose response fashion for both peak and trough tests and for both qd and bid regimens. There was also a dose related decrease in exercise induced ST segment depression and an increase in time to 1 mm ST depression. In 15 patients, 24-hour ambulatory monitoring also revealed a decrease in episodes of silent ischemia. No significant side effects related to the study drug occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗