Hemodynamic effects of felodipine at rest and during exercise in exertional angina pectoris

Effect of felodipine on regional blood supply and collateral vascular resistance in patients with peripheral arterial occlusive disease

This double-blinded, randomized, placebo-controlled study was designed to investigate the acute effect of felodipine on regional blood supply and collateral vascular resistance in patients with peripheral arterial occlusive disease (PAOD). Thirty men with PAOD were treated with a single dose of 5 mg felodipine or placebo. Systolic blood pressure (SBP), Doppler ankle pressure (DAP), calf blood flow (CBF) by venous occlusion plethysmography and calf transcutaneous oxygen tension (tcpO2) were measured during a cycle ergometry. Felodipine reduced SBP significantly (from 149 to 136 mmHg, p < 0.05), while placebo did not. DAP increased slightly but not significantly in both groups. The pressure gradient between SBP and DAP fell significantly in the felodipine group (60 vs 39 mmHg, p < 0.01) but not in the placebo group (59 vs 56 mmHg). There was a trend for lower velocity in tcpO2 decrease during the stress test and higher velocity of tcpO2 increase during recovery from exercise in the felodipine group although the differences between both groups were not significant. In the felodipine group, CBF increased by 35.6% (p < 0.05) whereas it did not change in the placebo group. In conclusion, while lowering SBP, felodipine increased slightly, or at least maintained, the blood supply to the calves in PAOD patients, which probably results from reducing collateral vascular resistance.

Hemodynamic and antiischemic effects of intravenous elgodipine, a new dihydropyridine calcium channel blocker, in patients with chronic stable angina

Elgodipine is a new second-generation dihydropyridine calcium antagonist. Its hemodynamic and antiischemic properties were evaluated in a single-blind, placebo-controlled trial in 22 males with chronic stable angina. Coronary artery disease was angiographically confirmed. Measurements were performed with a Swan-Ganz thermodilution catheter during a 30-minute period of rest and before the end of a 4-minute bicycle exercise test at maximum individual workload, both with placebo (IV infusion of 5 ml saline over 30 minutes) and elgodipine (10 micrograms/kg/2 min bolus IV, then IV infusion of 1 micrograms/kg/min for 28 minutes. Elgodipine caused very similar hemodynamic changes at rest and during exercise. Its major hemodynamic modification was the marked decrease in systemic vascular resistance, which was accompanied by an increase in cardiac index and stroke volume. Mean arterial blood pressure was slightly reduced, whereas the opposite small increase in heart rate meant that the double product remained unchanged. Contrary to resting conditions, pulmonary capillary wedge pressure, pulmonary artery pressures, pulmonary vascular resistance, and mean right atrial pressure remained normal or increased to a lesser extent during exercise after elgodipine. After elgodipine ischemic ST depression during exercise was diminished, and 11 of 16 assessable patients remained free from angina pectoris. We conclude that elgodipine is an efficacious antianginal drug. Its major mechanism of action is lowering of systemic vascular resistance. Thus elgodipine improves systolic cardiac function in patients with chronic stable angina and may delay the onset of ischemic diastolic dysfunction during exercise, as indicated by a normal left ventricular end-diastolic pressure (LVEDP). The data also suggest an improvement in coronary blood flow during exercise.

Treatment of hypertension with felodipine in patients with concomitant diseases

Coexisting medical conditions often complicate the selection of antihypertensive drugs. Felodipine, a new vascular-selective calcium antagonist with demonstrated antihypertensive efficacy, has not been found to alter lipid profiles in hypertensive patients. Studies in additional patient populations have yielded insights into the effects of the drug on other diseases that may coexist with hypertension. In individuals with stable angina pectoris or congestive heart failure, acute administration of felodipine reduces systemic vascular resistance and increases cardiac output and total coronary blood flow; myocardial contractility is not depressed at doses that produce a clinically significant reduction in vascular resistance. In patients with coronary stenoses, the drug increases vessel diameter in the vicinity of obstructive lesions. Single-dose and long-term studies in patients with exertional angina have found that felodipine reduces anginal frequency and improves exercise tolerance. In patients with congestive heart failure, chronic dosing with felodipine produces a persistent reduction in vascular resistance and an increase in cardiac output, both at rest and during exercise. Symptomatic improvement and increased exercise tolerance have been noted in some studies. In patients with Raynaud's phenomenon, felodipine has been associated with a dose-dependent improvement in symptomatology. Among individuals with exercise-induced bronchospasm, the drug has no effect on resting bronchial tone and may exert some positive effects during exercise. In hypertensive patients with Type II diabetes, felodipine has not been found to raise glucose levels significantly. The data obtained thus far suggest that felodipine is safe for use in hypertensive patients with a variety of concomitant diseases.

Twenty-four-hour activity of felodipine extended release in chronic stable angina pectoris

To investigate the antiischemic efficacy and duration of action of the dihydropyridine calcium antagonist felodipine, 15 patients with stable exertional angina were enrolled in a double-blind, crossover study comparing 2 doses (5 and 10 mg) of felodipine extended release (ER) and placebo given once daily for 1 week. Bicycle exercise tests were repeated at the end of each treatment period 4 and 24 hours after dosing. Four hours after dosing with both felodipine doses, only 5 patients discontinued the exercise test because of greater than 2 mm of ST-segment depression, whereas 10 continued until exhaustion (p less than 0.01 vs placebo). Compared with placebo, total exercise time was increased by 19% (p less than 0.001), with no difference between doses. After 24 hours, exercise duration was prolonged up to physical exhaustion in 6 patients taking felodipine 10 mg (p less than 0.05 vs both placebo and felodipine 5 mg); moreover, 11 patients taking 10 mg and 5 taking 5 mg increased time to 1 mm of ST depression greater than or equal to 15% compared with exercise time during the placebo test. Mean time to 1 mm of ST depression at 24 hours was increased by 8% with 5 mg and by 18% with 10 mg (p less than 0.001 vs placebo; p less than 0.01 between doses). Total exercise time at 24 hours was increased with both doses (p less than 0.001), with greater efficacy with the 10-mg dose (p less than 0.05 vs 5 mg).(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of felodipine in angina pectoris

The clinical response to felodipine, in addition to a beta-blocker, was evaluated and compared with placebo in this double-blind cross-over study. Twenty patients with exertional angina pectoris completed the study. Felodipine reduced the number of angina attacks and the Glyceryl Trinitrate (GTN) consumption. The median exercise capacity was increased 33% after 4 weeks' felodipine treatment compared with placebo. At maximal exercise, systolic blood pressure and rate pressure product were reduced by felodipine while no change was seen in heart rate or ST-depression. Felodipine reduced both supine and erect blood pressure. The mean supine blood pressure at rest was 138/82 mm Hg after four weeks' placebo treatment compared with 114/71 mmHg after felodipine 5-10 mg b.i.d. Felodipine has overall a modest but significant anti-anginal benefit when combined with a beta-blocker.

Felodipine in severe chronic congestive heart failure: acute effects on central hemodynamics and regional blood flow distribution

In order to assess the effect of felodipine, a new calcium antagonist with vascular selectivity, on regional blood flow distribution at rest in chronic congestive heart failure, ten patients were studied during an acute test. Right heart catheterization allowed the evaluation of hemodynamic parameters; renal blood flow was calculated using paraamino-hippuric acid clearance; hepatic blood flow measurement was based on indocyanine green clearance; and limb blood flow was assessed with venous occlusion plethysmography. Blood samples were collected for the analysis of plasma catecholamines, renin, and aldosterone. All parameters were recorded in duplicate under basal conditions and after felodipine infusion. The infusion of felodipine induced a significant increase in cardiac index, stroke work index, and limb blood flow. Systemic and pulmonary arterial blood pressure, pulmonary wedge pressure, and systemic resistance underwent a significant decrease. The heart rate, pulmonary resistance, renal blood flow, and hepatic blood flow were not changed. In conclusion, felodipine was of benefit in congestive heart failure at rest in an acute test, acting through a marked decrease in vascular resistance and a consequent improvement in cardiac output and limb blood flow. No changes in renal and hepatic blood flow were observed.

Ambulatory blood pressure monitoring during sustained treatment with conventional and extended-release felodipine in mild-to-moderate hypertension

To assess the duration of the antihypertensive effect of the dihydropiridine calcium antagonist felodipine in conventional (C-F) and slow-release (ER-F) formulations, 12 patients with essential hypertension underwent ambulatory blood pressure monitoring (ABPM) at the end of a 2-week treatment period with C-F 5 mg b.d., ER-F 10 mg once daily (o.d.) and placebo. C-F, ER-F and placebo were given in a double-blind 3 x 3 latin square design 4 times replicated. There was no systematic change in the ABP profile over the three study periods regardless of the treatment. In comparison to placebo, the mean 24-h systolic and diastolic blood pressures showed a significant and similar reduction after both formulations of F. Compared to placebo, C-F and ER-F induced a significant reduction in systolic blood pressure for 15 and 21 h, respectively, and of diastolic blood pressure for 16 and 21 h, respectively. Three patients complained of headache (mild in 2, moderately severe in 1), and two patients of nocturia, with either formulation of F.

The effects of treatment with felodipine as a single agent in coronary artery disease

In an earlier study one dose of the vasodilator felodipine improved haemodynamic function in patients with angina without having a negative inotropic effect. The haemodynamic response of sustained treatment with felodipine as a single agent in stable angina was investigated in a double blind crossover study of 25 patients. The dosage of felodipine was increased from 5 mg twice daily to 10 mg twice daily after two weeks. Twenty one patients completed the study, two were withdrawn because of acute myocardial infarction, and a further two because of symptoms of vasodilatation. Felodipine reduced both supine and erect blood pressure and increased the resting heart rate. Median exercise time was increased by 10% at two weeks and 7% at four weeks. There was a sustained reduction in the number of angina attacks and use of sublingual nitrate on active treatment. Felodipine has antianginal effects but these are limited and seem less than those of other related compounds. This finding is unexpected and possibly related to increased heart rate.

The role of nitrates, beta blockers, and calcium antagonists in stable angina pectoris

Numerous controlled studies have shown that nitrates, beta blockers, and calcium antagonists are effective in the treatment of stable angina pectoris. The pharmacokinetics, pharmacodynamics, and hemodynamic effects of these agents are different, and thus combination therapy offers additive improvement and also counterbalancing of the undesirable side effects of each drug. The choice of therapy depends on the severity of symptoms, associated diseases, compliance, side effects, and status of left ventricular function. The main mechanism of improvement is a decrease in myocardial oxygen consumption, though an increase in coronary blood flow is another potential reason for the use of calcium blockers. This review considers the properties of these drugs, their mechanism of action, and the results of randomized studies.

Acute effects of felodipine in exertional angina pectoris

To investigate the antianginal efficacy, duration of action and tolerability of 2 doses of the new calcium antagonist felodipine, 15 patients (14 men and 1 woman, mean age 62 years) with stable exertional angina pectoris and angiographically demonstrated coronary artery disease were randomly given felodipine, 5 and 10 mg, and placebo on 3 different days. A bicycle ergometer exercise test was performed 3 and 10 hours after dosing. In comparison with placebo, felodipine 5 and 10 mg significantly increased resting heart rate and decreased resting systolic and diastolic blood pressure 3 hours after administration (p less than 0.001). Ten hours after administration, only supine systolic blood pressure was still significantly lower (p less than 0.001). Anginal (time to mild chest pain) and ischemic (time to 1 mm ST depression) thresholds, as well as duration of exercise and total work at peak exercise, were higher in comparison with placebo at 3 and 10 hours (p less than 0.001). In comparison with the lower dose, 10 mg felodipine induced a decrease in supine (p less than 0.05) and sitting (p less than 0.01) systolic blood pressure at rest and an increase in total work to anginal threshold (p less than 0.01), as well as in total work and duration of exercise at peak exercise (p less than 0.05). These results suggest that a single administration of felodipine, 5 and 10 mg, may improve exercise capacity over a 10-hour period in patients with stable exercise-induced angina due to atherosclerotic heart disease.

Hemodynamic effects of felodipine in congestive heart failure

The hemodynamic effects of increasing dosages of felodipine, a new calcium antagonist with selective vasodilator properties, were studied in 13 patients with chronic cardiac failure. A Swan-Ganz thermodilution catheter was positioned in the pulmonary artery and hemodynamic parameters were monitored from 9 am to 6 pm for five days. On the first and the fifth day patients received placebo (P) and on the second, third, and fourth day patients received felodipine 5, 10, and 20 mg, respectively. Symptom-limited exercise tests with a bicycle ergometer were performed on both days of P and on the fourth day. A marked reduction of systemic vascular resistance (SVR) and a significant increase of cardiac index without increments of heart rate (HR) were observed after felodipine at rest. A dose response effect could be demonstrated. During exercise a significant increment of cardiac index and decrease of pulmonary wedge pressure was observed after felodipine. Felodipine showed a potent vasodilator action on systemic circulation with significant changes on both stroke volume and filling pressures at rest and during exercise without side effects.

Felodipine-induced dilatation of epicardial coronary arteries. A randomized, double-blind study

Dilatation of large coronary arteries is of potential value in the treatment of angina pectoris. In this double-blind study, the acute effect of felodipine or placebo on coronary artery dilatation was studied in patients with severe angina pectoris with the aid of coronary arteriography. There were two parallel groups, one with 9 patients who received felodipine, the other with 12 patients who received placebo. Measurements of vessel diameters were performed at a proximal position of the affected artery, at the site of the stenosis, and distal to the lesion. The mean plasma felodipine concentration was 17+/-6 nmol/l. The systolic blood pressure was reduced from 156+/-15 to 145+/-13 mm Hg after felodipine (p less than 0.05), but was unaffected by placebo. The heart rate and arterial catecholamine levels were basically unchanged in both groups of patients. The proximal arterial segment was dilated 7% after felodipine (p = 0.05), the stenosis area 9% (N.S.) and the distal part of the vessel 7% (p less than 0.05). There were no changes in coronary diameters in the placebo group. In conclusion, felodipine dilates large coronary arteries, and this mode of action may be valuable in the treatment of patients with coronary artery disease, especially in cases where coronary spasm is a prominent feature.

Acute haemodynamic effects of felodipine in congestive heart failure

The haemodynamic effects of felodipine 0.1 mg/kg p.o., a new arteriolar dilator, were studied in 7 patients with severe congestive heart failure of NYHA Class IV (Group A) and in 3 patients in Class II-III (Group B). In Group A, measurements were made before and 1 and 4 h after felodipine administration. There was a substantial fall in systemic arterial pressure, which was not associated with a compensatory tachycardia. In fact, there was a fall in heart rate from 92 to 82 beats/min 1 h after drug administration. The pulmonary capillary wedge pressure was reduced from 22 to 14 mm Hg and the cardiac index and stroke volume index rose significantly. Consequently, there was a marked reduction in systemic vascular resistance. In Group B measurements were performed at rest and during exercise before and 1 h after felodipine. The pulmonary wedge capillary pressure during exercise was lower than in the control situation. Coronary sinus flow was increased and there was a pronounced fall in coronary vascular resistance. The results would suggest that felodipine, by virtue of its ventricular unloading potency, might be a valuable drug in the treatment of congestive heart failure.

Effects of nicardipine on coronary blood flow, left ventricular inotropic state and myocardial metabolism in patients with angina pectoris

The effects of intravenous nicardipine (2.5 mg) on the left ventricular (LV) inotropic state, LV metabolism, and coronary haemodynamics were analysed in 22 patients with angina pectoris. Measurements were made at fixed heart rate (atrial pacing), under basal state, and during a cold pressor test. After nicardipine, coronary blood flow and oxygen content in the coronary sinus increased significantly. The indices of inotropic state increased slightly, and the rate of isovolumic LV pressure fall improved. Myocardial oxygen consumption was unchanged despite the significant reduction in pressure-rate product, but LV lactate uptake increased, particularly during the cold pressor test. When nicardipine was administered after propranolol, the indices of inotropic state were unaffected. The lack of direct effect of nicardipine on LV inotropic state was further confirmed by intracoronary injection of 0.1 and 0.2 mg in a separate group of 10 patients. It is concluded that the nicardipine-induced coronary dilatation seems to improve perfusion and aerobic metabolism in areas with chronic ischaemia, resulting in reduced lactate production and augmented oxygen consumption.

Effects of nicardipine and nisoldipine on myocardial metabolism, coronary blood flow and oxygen supply in angina pectoris

The effects of the calcium antagonists nicardipine and nisoldipine on left ventricular (LV) metabolism were analyzed in 32 patients with angina pectoris. Measurements were made at a fixed heart rate under the basal state and during a cold pressor test (CPT). After administration of the drugs, coronary blood flow increased significantly and the mean aortic pressure decreased by 10% (p less than 0.01) in the basal state and by 11% (p less than 0.01) during CPT. Despite the reduction in pressure-rate product, myocardial oxygen consumption was unchanged in the basal state (18 +/- 4 vs 19 +/- 4 ml/min, difference not significant) and during CPT (21 +/- 5 vs 21 +/- 5 ml/min, difference not significant); this discrepancy between a reduced pressure-rate product and an unchanged oxygen consumption was also noted when nicardipine was given after propranolol (0.1 mg/kg; 12 patients). Both agents also increased LV lactate uptake, particularly during CPT (+13 mumol/min, p less than 0.05 vs control CPT) and reduced LV glutamine production. In 10 patients in whom 14C-lactate was infused, the chemical LV lactate extraction ratio increased more than the 14C-lactate extraction ratio after administration of the drugs, indicating a reduction in LV lactate production. The data are consistent with the hypothesis that nicardipine and nisoldipine improve perfusion and aerobic metabolism in chronically ischemic areas, resulting in an augmented oxygen consumption and in a reduced lactate production.