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

Nicardipine versus nitroglycerin for hypertensive acute heart failure syndrome: a single-center observational study

Objective: Nitroglycerin is a first-line treatment for hypertensive acute heart failure syndrome (AHFS). However, nicardipine is frequently used to treat hypertensive emergencies, including AHFS. In this study, we compared the effectiveness of nicardipine and nitroglycerin in patients with hypertensive AHFS.

Patients and Methods: This single-center, retrospective, observational study was conducted at the intensive care unit of a Japanese hospital. Patients diagnosed with AHFS and systolic blood pressure 140 mmHg on arrival between April 2013 and March 2021 were included. The outcomes were the time to optimal blood pressure control, duration of continuous infusion of antihypertensive agents, duration of positive pressure ventilation, need for additional antihypertensive agents, length of hospital stay, and body weight changes. Outcomes were compared between the nicardipine and nitroglycerin groups. We also compared these outcomes between the groups after excluding patients who received renal replacement therapy.

Results: Fifty-eight patients were enrolled (26 and 32 patients were treated with nitroglycerin and nicardipine, respectively). The nicardipine group had a shorter time to optimal blood pressure control (2.0 [interquartile range, 2.0–8.5] h vs. 1.0 [0.5–2.0] h), shorter duration of continuous anti-hypertensive agent infusion (3.0 [2.0–5.0] days vs. 2.0 [1.0–2.0] days), less frequent need for additional anti-hypertensive agents (1 patients [3.1%] vs. 11 patients [42.3%]), and shorter length of hospital stay (17.5 [10.0–33.0] days vs. 9.0 [5.0–15.0] days) than the nitroglycerin group. The duration of positive pressure ventilation and body weight changes were similar between the groups. The outcomes were similar after excluding patients who received renal replacement therapy.

Conclusion: Nicardipine may be more effective than nitroglycerin for treating hypertensive AHFS.

Comparison of the ability of nicardipine, theophylline and zaprinast to restore cardiovascular haemodynamics following inhibition of nitric oxide synthesis

1. The use of pharmacological inhibitors of nitric oxide (NO) synthesis to treat patients with septic shock is limited by the observation that they cause a fall in cardiac output in some subjects. The aim of this work was to investigate this fall and to test whether it was reversible by subsequent administration of nicardipine, theophylline or the cyclic GMP-selective phosphodiesterase inhibitor, zaprinast (M&B 22948). 2. In pentobarbitone-anaesthetized pigs, haemodynamic indices were measured before and after intravenous administration of NG-nitro-L-arginine methyl ester (L-NAME) in a dose-response protocol (0.2-20 mg kg-1; n = 6) and as a single bolus of 10 mg kg-1 either alone or followed by increasing doses of nicardipine, theophylline or zaprinast (n = 8 in each group). 3. L-NAME caused a dose-dependent rise in systemic vascular resistance and mean systemic arterial pressure and a dose-dependent fall in cardiac output. A single bolus of L-NAME (10 mg kg-1) produced these effects within 15 min. 4. Subsequent administration of nicardipine (0.05-0.2 mg kg-1) caused complete reversal of systemic vasoconstriction and hypertension and in doing so completely restored cardiac output. Theophylline (7.5-10 mg kg-1) partially reversed the rise in systemic vascular resistance and partially restored cardiac output but the effect was small compared to that of nicardipine. Zaprinast (1-5 mg kg-1) had no significant effect on any of these variables. 5. These results suggest that reduced cardiac output following inhibition of NO synthesis is an effect of increased afterload on the heart and is reversible by nicardipine and to a lesser extent by theophylline.These findings may have potential value for those using NO synthase inhibitors to treat patients with septic shock.

Comparison of the cardiovascular effects of nifedipine and nicardipine in the presence of atenolol

A placebo controlled double blind crossover study was performed in 12 healthy volunteers to compare the cardiovascular effects of single oral doses of nifedipine (5, 10 and 15 mg) and nicardipine (20 and 30 mg) in the presence of atenolol 100 mg. Haemodynamic measurements were made by transthoracic electrical bioimpedance cardiography (TEBC) 2 h following drug administration during passive tilting, graded bicycle exercise (30-150 W) and recovery from exercise. In the absence of calcium channel blockade, atenolol reduced mean blood pressure, heart rate, and cardiac index, and increased stroke volume, peripheral resistance, pre-ejection period, and ventricular ejection time, particularly during and after exercise. In comparison with atenolol alone, addition of nifedipine or nicardipine reduced peripheral resistance but did not produce significant changes in stroke volume, cardiac output, dZ/dt [max], pre-ejection period (PEP). Ventricular ejection time (VET), PEP/VET, or Heather index at any point in the experiment. Similar reductions in peripheral resistance were produced by nifedipine 10 mg and nicardipine 20 and 30 mg. These apparently equivalent doses of nifedipine and nicardipine had similar effects on stroke volume, cardiac index, PEP/VET and Heather index. Thus the increases in ventricular performance previously demonstrated in association with nifedipine and nicardipine therapy were not observed in the presence of beta-adrenoceptor blockade. Under these conditions no important differences have been observed in the cardiovascular effects of these two calcium channel blockers.

Left ventricular diastolic function in patients with left ventricular systolic dysfunction due to coronary artery disease and effect of nicardipine

To assess the effect of nicardipine on left ventricular (LV) diastolic function independent of concurrent effects on loading conditions in patients with LV systolic dysfunction due to coronary artery disease, equihypotensive doses of intravenous nitroprusside and nicardipine were administered to 12 patients with congestive heart failure due to previous myocardial infarction (LV ejection fraction less than 0.40). LV micromanometer pressure and simultaneous radionuclide volume were obtained during a baseline period, during nitroprusside infusion, during a second baseline period and during nicardipine infusion. Mean systemic arterial pressure decreased an average of 21 mm Hg with nitroprusside and 19 mm Hg with nicardipine. A greater decrease in LV end-diastolic pressure was observed with nitroprusside (29 +/- 2 to 15 +/- 2 mm Hg, p less than 0.01) than with nicardipine (29 +/- 2 to 25 +/- 3 mm Hg, p less than 0.05). There was a decrease in the time constant of relaxation during nitroprusside but not during nicardipine infusion. There was enough overlap in LV volumes in the baseline and nitroprusside periods to compare diastolic pressure-volume relations over a common range of volumes in 4 patients, and enough overlap in the baseline and nicardipine periods in 11 patients. The relation was shifted downward in 3 of 4 patients taking nitroprusside and in 6 of 11 patients taking nicardipine. The relation between end-diastolic pressure and volume was not shifted with nicardipine.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy and safety of intravenous nicardipine in the control of postoperative hypertension. IV Nicardipine Study Group

In a double-blind, randomized, multicenter study, the efficacy and safety of intravenous (IV) nicardipine was compared with placebo in the control of postoperative hypertension in cardiac and noncardiac surgical patients. One hundred twenty-two patients (17 cardiac and 105 noncardiac surgery) met the entry criteria (systolic BP greater than or equal to 140 mm Hg or diastolic BP greater than or equal to 95 mm Hg) and were randomized (3:2) to receive IV nicardipine (n = 71) or placebo (n = 51). Therapeutic response (greater than or equal to 15 percent reduction in BP from baseline) was achieved in 94 percent of patients treated with IV nicardipine vs 12 percent with placebo (p less than 0.001). The mean response time and infusion rate for IV nicardipine were 11.5 (+/- 0.8) minutes and 12.8 (+/- 0.3) mg/h, respectively. The magnitude of BP reduction was similar in both cardiac and noncardiac postsurgical patients. Blood pressure control was sustained with minimal dose adjustments of IV nicardipine (3.0 +/- 0.2 mg/h) during a prolonged maintenance infusion period of 6.8 +/- 0.5 h. A reflex mean increase in heart rate of 5 bpm was seen in patients treated with IV nicardipine. Sixteen patients (15 noncardiac and one cardiac surgery) had a sustained heart rate of greater than 100 bpm, with a mean increase of 24 bpm from the baseline. In all these patients except three, tachycardia was resolved while receiving nicardipine. None of these patients who had development of tachycardia during nicardipine therapy had exhibited ST segment changes indicative of ischemia. One patient with tachycardia at baseline had exhibited ST segment depression (3 to 4 mm) during nicardipine treatment, which was resolved following discontinuation of nicardipine therapy and application of nitroglycerin (Nitropaste). Hemodynamic evaluation revealed that IV nicardipine significantly decreased mean arterial pressure, systemic vascular resistance, and significantly increased cardiac index with no change in heart rate. These hemodynamic changes were similar in cardiac and noncardiac surgical patients. Adverse experiences reported with IV nicardipine included hypotension (4.5 percent), tachycardia (2.7 percent), and nausea/vomiting (4.5 percent). In the placebo group, the incidence of adverse experience was 6 percent, with an equal distribution of hypotension (2 percent), nausea/vomiting (2 percent), and headache (2 percent). No clinically important changes in laboratory variables related to IV nicardipine were reported. In conclusion, these findings indicate that nicardipine, a titratable intravenous calcium channel blocker, can rapidly and effectively control postoperative hypertension in cardiac and noncardiac surgical patients.

New calcium antagonists: relevance of vasoselectivity

The calcium antagonists are a heterogeneous class of drugs used to treat a number of cardiovascular disorders. A new generation of calcium antagonists under development have a higher degree of selectivity for vascular smooth muscle and coronary vasculature compared with verapamil, nifedipine, and diltiazem. The clinical relevance of vasoselectivity and its impact on drug selection are discussed. The newer calcium antagonists are important alternatives to older agents and may be associated with improved tolerance and a reduced incidence of adverse effects. Their place in therapy has yet to be defined by comparative studies of efficacy and safety.

The cardiovascular effects of oral nifedipine and nicardipine: a double-blind comparison in healthy volunteers using transthoracic bioimpedance cardiography

The cardiovascular effects of single oral doses of nifedipine (5 and 10 mg) and nicardipine (20 and 30 mg) were compared in a placebo controlled double-blind crossover study involving 8 healthy male volunteers. Two hours following drug administration stroke volume and cardiac index were measured non-invasively using transthoracic electrical bioimpedance cardiography during passive tilting, graded bicycle exercise, and recovery from exercise. Two separate experiments were performed in the absence of active drug to allow the reproducibility of the measurements to be assessed. Coefficients of variation (within experiment/between experiments) for cardiac index were 7.0%/19.9% at rest and 11.5%/9.3% at 180 W exercise. Both nifedipine and nicardipine increased stroke volume and cardiac index and reduced total peripheral resistance (mean blood pressure/cardiac index) at all times in the experiment. Reductions in peripheral resistance were similar for nifedipine 10 mg and nicardipine 20 mg but in these doses slightly larger increases in heart rate were produced by nifedipine, and in stroke volume and cardiac index with nicardipine. The study shows that the cardiovascular effects of nifedipine and nicardipine can be detected using impedance cardiography which is a simple, safe, and inexpensive technique. The differences between the effects of the two drugs were small. Although some were of statistical significance and are consistent with a less marked cardiodepressant effect for nicardipine, the clinical importance of these observations is uncertain. Further studies to examine the effect of oral nifedipine and nicardipine in patients with impaired ventricular function may be helpful in clarifying this tissue.

Techniques for assessing inotropic effects of drugs in patients with heart failure: application to the evaluation of nicardipine

Evaluation of new drugs for the treatment of patients with heart failure requires assessment of the inotropic effects of these agents. Use of traditional indexes of contractility has been limited by the confounding effects of load on these measures of contractile function, although they have yielded meaningful conclusions in some studies. Recently, the end-systolic pressure volume relation (ESPVR) has emerged as a relatively load-independent measure of contractility. Because it is difficult to construct the relation in the clinical setting, several approximations have been introduced, some of which have significant limitations. We have applied the ESPVR to the assessment of the inotropic effect of the new dihydropyridine calcium channel blocker, nicardipine, in 15 patients with heart failure caused by systolic dysfunction. We constructed left ventricular pressure-volume loops from micromanometer pressure and radionuclide volume and manipulated afterload with nitroprusside. In response to intravenous nicardipine, mean arterial pressure fell from 91 +/- 4 (mean +/- SEM) to 72 +/- 2 mm Hg, left ventricular end-diastolic pressure fell from 27 +/- 2 to 23 +/- 3 mm Hg, cardiac index increased from 1.7 +/- 0.1 to 2.4 +/- 0.1 L/min/m2, and left ventricular ejection fraction increased from 0.15 +/- 0.01 to 0.19 +/- 0.01 (all p less than 0.05). Heart rate did not change. A rightward shift of the ESPVR, indicating a negative inotropic effect of nicardipine, was observed in 12 of 14 patients (p less than 0.05). We conclude that nicardipine improves left ventricular pump performance despite its negative inotropic effect in patients with severe heart failure. The improvement in pump performance can be attributed to afterload reduction.

Inotropic effect of nicardipine in patients with heart failure: assessment by left ventricular end-systolic pressure-volume analysis

Nicardipine, a new dihydropyridine calcium channel blocker, has been investigated for the treatment of coronary artery disease and heart failure. To assess the inotropic effect of nicardipine in humans independent of its vasodilator effect, equihypotensive doses of intravenous nitroprusside (mean infusion rate 65 +/- 13 micrograms/min) and nicardipine (mean dose 5.2 +/- 0.4 mg) were administered to 15 patients with heart failure (New York Heart Association functional classes II to IV, radionuclide left ventricular ejection fraction 0.15 +/- 0.02). Left ventricular micromanometer pressure and simultaneous radionuclide left ventricular volume were obtained at baseline, during nitroprusside infusion, during a second baseline period and during nicardipine infusion. Heart rate did not change significantly with either nitroprusside or nicardipine. Mean systemic arterial pressure decreased by an average of 21 mm Hg with both drugs. A greater decrease in left ventricular end-diastolic pressure occurred with nitroprusside (27 +/- 2 to 14 +/- 2 mm Hg, p less than 0.01) than with nicardipine (27 +/- 2 to 23 +/- 3 mm Hg, p less than 0.05), and pulmonary capillary wedge pressure decreased significantly only with nitroprusside. Cardiac index increased from 1.8 +/- 0.1 to 2.1 +/- 0.1 liters/min per m2 (p less than 0.05) with nitroprusside and to a greater extent from 1.7 +/- 0.1 to 2.4 +/- 0.1 liters/min per m2 (p less than 0.01) with nicardipine. Left ventricular ejection fraction increased with nicardipine (0.15 +/- 0.01 to 0.19 +/- 0.01, p less than 0.01), but not with nitroprusside. Peak positive first derivative of left ventricular pressure (dP/dt) decreased by 9% with both agents.(ABSTRACT TRUNCATED AT 250 WORDS)

Intracoronary injections of salbutamol demonstrate the presence of functional beta 2-adrenoceptors in the human heart

To demonstrate the presence of functional cardiac beta 2-adrenoceptors in man, we studied the responses to intracoronary injections of salbutamol in three groups of six patients. We injected salbutamol, a selective beta 2-adrenoceptor agonist, into the right coronary artery to avoid peripheral vasodilator action and to stimulate the sinoatrial node directly. Salbutamol injections caused a sinus tachycardia. The same doses of salbutamol injected into the aortic root caused no change in heart rate, ruling out a systemic effect. The mean dose required to cause an increase in heart rate of 30 beats/min (IHR30) was 2.6 micrograms in the first group of six patients. In 12 other patients salbutamol was given after beta-blockade to confirm the beta 2-selectivity of the responses. Doses of practolol (beta 1-selective blockade) and of propranolol (beta 1- and beta 2-blockade) that had equal beta 1-blocking activity were used. In six patients who were given practolol, the mean IHR30 dose was 2.1 micrograms. In six patients who were given propranolol, the mean IHR30 dose was significantly greater at 64 micrograms (p less than 0.001, practolol vs. propranolol). This study demonstrates that direct cardiac beta 2-adrenoceptor stimulation in man has a positive chronotropic effect.

Effects of nicardipine on chronic stable effort angina: a non-invasive assessment

The effects of 60 mg/day nicardipine hydrochloride were evaluated in a 4-week single-blind study on 12 patients with chronic stable effort angina. All patients completed the treatment with few reports of adverse effects. Nicardipine hydrochloride was effective in reducing the incidence of anginal attacks and consumption of glyceryl trinitrate. Treadmill exercise time, angina onset time and the time to 1 mm ST-segment depression were increased. The extent of ST-segment depression was reduced at maximum comparable exercise, with a reduced rate-pressure product and, at maximum exercise, with an increased rate-pressure product. Myocardial stress 201Tl scintillography was carried out in eight of the patients and showed improved washout in antero-septal, infero-apical and postero-lateral segments. Echocardiographic measures of left ventricular function were enhanced because of reduction of afterload. Systemic vascular resistance and end-systolic stress were also decreased and a significant correlation was found between the increase in ejection fraction and reduction of systolic blood pressure. It is concluded that nicardipine hydrochloride is effective in the control of stable effort angina by reducing myocardial oxygen consumption and enhancing coronary blood flow thereby improving left ventricular function.

Effects of nicardipine on coronary blood flow

Nicardipine, a new 1,4 dihydropyridine calcium antagonist, has chemical properties that permit both oral and stable intravenous preparations. These preparations have prominent effects on indices of myocardial ischemia, coronary blood flow, and myocardial oxygen consumption. Data are reviewed from animal models of myocardial ischemia and patient studies that suggest that nicardipine has very prominent effects acting to increase coronary blood flow and reduce myocardial oxygen demand, in addition to favorable effects on myocardial metabolism and function.

'Second generation' dihydropyridine calcium antagonists. Greater vascular selectivity and some unique applications

The newer dihydropyridine calcium antagonists are structurally related to nifedipine, but may provide greater vascular selectivity and wider clinical utility. Five new dihydropyridines-nisoldipine, nicardipine, nimodipine, felodipine and nitrendipine-are reviewed with regard to their preclinical pharmacology, haemodynamic effects and clinical indications. Nisoldipine is a potent arterial vasodilator with minimal electrophysiological and negative inotropic effects. Although data are still preliminary, the drug has shown some efficacy in both exertional angina and essential hypertension. The dosing interval is not yet clearly established, but may be twice daily. Utility in congestive heart failure awaits confirmation, but preliminary studies are promising. Nicardipine is an especially potent peripheral, cerebral and coronary arterial vasodilator that causes 10-fold less myocardial depression in animals than nifedipine, and may provide important cardioprotective effects during ischaemia. Human haemodynamic studies have confirmed nicardipine's lack of negative inotropism, its ability to reduce coronary and peripheral vascular resistance, and its lack of effect on cardiac conduction. Several controlled trials have documented its efficacy in exertional angina, vasospastic angina, and essential hypertension. Nicardipine's potential as an antiatherosclerotic agent is currently under investigation. Nimodipine is undergoing a unique clinical development programme aimed at cerebrovascular disorders. In almost all species, nimodipine selectively increases cerebral blood flow and reverses cerebral artery spasm without altering cerebral oxidative metabolism or systemic blood pressure. In humans, a large, double-blind, placebo-controlled trial in subarachnoid haemorrhage showed that nimodipine significantly reduced the severity of neurological deficits associated with delayed cerebral vasospasm. Several uncontrolled trials with larger numbers of patients support these results. Nimodipine has also proved useful in reducing cerebral artery spasm during intracranial surgery, and in the prophylactic treatment of migraine headaches. A preliminary study of nimodipine in acute stroke showed promising results in limiting neurological disability. Felodipine is a very potent systemic arterial vasodilator with negligible myocardial depressant activity. It is also a renal artery vasodilator. Unlike the other new dihydropyridines, felodipine prolongs the A-H interval on electrophysiological testing, but only to about 50% of that observed with verapamil. Felodipine is undergoing clinical trials in essential hypertension.(ABSTRACT TRUNCATED AT 400 WORDS)

Acute and chronic hemodynamic effects of nicardipine hydrochloride in patients with heart failure

Acute and chronic hemodynamic effects at rest and during exercise of a new dihydropyridine calcium antagonist, nicardipine hydrochloride, were studied in 10 patients with chronic heart failure. Acute intravenous administration of nicardipine resulted in a significant decrease in arterial blood pressure, systemic vascular resistance, and pulmonary capillary wedge pressure. There was a significant increase in cardiac index, stroke volume index, and the left ventricular stroke work index. Cardiac index measured at peak exercise increased significantly when compared with the cardiac index obtained at peak exercise before the infusion. After 9 days of continuous therapy with nicardipine, 30 mg three times a day, a significant decrease in arterial blood pressure and systemic vascular resistance and a significant increase in the cardiac index, stroke volume index, and left ventricular stroke work index at rest were observed in response to a single oral dose of 30 mg nicardipine. Data at peak exercise were also obtained before and 2 hours after the oral administration of nicardipine. With this comparison there was a significant increase in cardiac index, stroke work index, and exercise duration. It is concluded that in this group of patients with severe chronic heart failure, nicardipine enhanced myocardial performance during rest and exercise and this enhancement is sustained after 9 days of oral therapy.

Effects of nicardipine on exercise- and pacing-induced myocardial ischemia in angina pectoris

To define the effects of nicardipine, a new dihydropyridine calcium antagonist drug, on exercise- and pacing-induced myocardial ischemia, 15 men with coronary artery disease were studied during cardiac catheterization. Nicardipine was administered intravenously as a 2-mg bolus followed by an infusion titrated to maintain a 10- to 20-mm Hg decrease in systolic arterial pressure. At rest, nicardipine decreased systemic and coronary vascular resistances, left ventricular end-diastolic pressure and increased coronary blood flow, heart rate and myocardial oxygen consumption. During bicycle exercise-induced myocardial ischemia, nicardipine significantly prolonged exercise duration and time to 1 mm of ST-segment depression. These changes were associated with no alteration in the product of systolic pressure and heart rate, decreased left ventricular end-diastolic pressure, systemic and coronary vascular resistances and increased coronary blood flow, as well as myocardial oxygen consumption. During atrial pacing, the heart rate threshold for myocardial ischemia was not changed by nicardipine administration, despite improvement in the ratio of coronary blood flow to myocardial oxygen consumption and hemodynamic changes otherwise similar to those during exercise. Nicardipine favorably influenced myocardial metabolic state, as indexed by lactate extraction during pacing-induced ischemia. Nicardipine is a potent coronary and systemic vasodilating drug that improves exercise tolerance and myocardial metabolic response to pacing stress, the mechanism for which appears to be partially mediated through increased coronary blood flow.

Myocardial protection by intracoronary nicardipine administration during percutaneous transluminal coronary angioplasty

To determine if the calcium antagonist nicardipine protects the myocardium against ischemia, myocardial lactate, hypoxanthine and prostanoid function was studied in 12 patients during percutaneous transluminal coronary angioplasty (PTCA). Values were obtained before balloon inflation and during 4 minutes after deflation. Intracoronary injection of 0.2 mg of nicardipine distal to the stenosis was done randomly before the first or second inflation; the other inflation served as a control. One minute after deflation, coronary sinus flow levels were similar during the nicardipine and control procedure (161 +/- 61 vs 159 +/- 72 ml/min); lactate (-9 +/- 21% vs -17 +/- 21%, p less than 0.025) and hypoxanthine production (-107 +/- 85% vs -218 +/- 153%, p less than 0.05) were less severe after nicardipine pretreatment than after control. All patients reverted to lactate extraction 4 minutes after inflation plus nicardipine infusion, whereas lactate was still produced 4 minutes after control inflation. No significant changes in thromboxane B2 or prostacyclin levels were observed in the coronary sinus 1 minute after inflation, but higher arterial thromboxane B2 values were observed after control inflation than after inflation with nicardipine infusion (median values 169 vs 78 pg/ml, p less than 0.05). In conclusion, intracoronary infusion of nicardipine reduced signs of ischemia and alterations in prostanoid handling after coronary occlusion. The mechanisms of myocardial protection appeared unrelated to coronary sinus blood flow changes or to a systemic effect of nicardipine.

Nicardipine. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic efficacy, in the treatment of angina pectoris, hypertension and related cardiovascular disorders

Nicardipine is an antagonist of calcium influx through the slow channel of the cell membrane and has been shown to be an effective and relatively well-tolerated treatment for stable effort angina and rest angina due to coronary artery spasm, and mild to moderate hypertension. Although its exact mechanism of action in these disease states has not been precisely defined, the potent coronary and peripheral arterial dilator properties of nicardipine, with concomitant improvements in oxygen supply/demand and reductions in systemic vascular resistance, are of major importance. Clinical studies have shown that nicardipine appears to be effective in the treatment of chronic stable exercise-induced angina pectoris and possibly in angina at rest due to coronary artery spasm. In the treatment of stable angina, nicardipine has proved to be equally as effective as nifedipine. However, haemodynamic and clinical studies indicate that nicardipine may have a further advantage of not depressing cardiac conduction or left ventricular function, even in patients with compromised cardiac pumping ability. Nicardipine also appears to be useful as initial monotherapy or in combination with other antihypertensive drugs when used in the treatment of mild to moderate hypertension, and may have some advantages over other vasodilators in this regard in that it may not be as frequently associated with fluid retention or weight gain as other similar drugs. In the treatment of hypertension nicardipine has been shown to be as effective as drugs such as hydrochlorothiazide, cyclopenthiazide, propranolol and verapamil in short term studies although confirmation of its long term usefulness in well-designed clinical trials is still required. Similarly, although the use of nicardipine in other disorders such as congestive heart failure and cerebrovascular disease has provided encouraging preliminary results, more studies are needed to clarify its place in their treatment. Side effects appear to be dose related and more frequent within the first few weeks of therapy. Most of these effects are minor and transient in nature and include headache, flushing and peripheral oedema. Thus, there is no doubt that nicardipine provides a suitable alternative to other drugs available for the treatment of angina and hypertension. However, further well-designed comparative clinical trials are needed to clarify its relative place in the long term management of these disorders.

Metabolic and hemodynamic effects of nicardipine during pacing-induced angina pectoris

During repeat exercise testing in 10 patients with stable angina, individual optimal doses of nicardipine were determined. Hemodynamic values and cardiac metabolism were studied during 2 pacing periods carried out before and after this dose (mean 5.3 mg). Postpacing ST-segment depression diminished (1 mm) after nicardipine administration (p less than 0.05), whereas pacing time to onset of angina did not change. Nicardipine administration increased heart rate 16% (p less than 0.005) and reduced systolic (10%) and diastolic (8%) blood pressures (both p less than 0.005). Coronary blood flow increased 16% (p less than 0.05) and coronary vascular resistance decreased 24% (p less than 0.01). Myocardial oxygen consumption was unchanged despite an 11% decrease in rate-pressure product during pacing (p less than 0.02). In the control state before nicardipine administration, metabolic signs of ischemia included release of lactate across the heart in 7 patients, decreased mean free fatty acid and glutamate uptake and alanine release during pacing, together with increased glucose uptake and citrate release during recovery. After nicardipine lactate release decreased in 5 of the 7 patients, pacing no longer changed free fatty acid, glutamate and alanine uptake/release from the level at rest. During recovery glucose uptake was reduced and citrate release was unaffected. The hemodynamic data indicate that nicardipine is a systemic and coronary vasodilator, increasing oxygen supply to the ischemic myocardium. The metabolic results indicate a change in substrate utilization toward that of normal heart, suggesting improved aerobic energy supply.

The acute haemodynamic effects of nicardipine in patients with chronic left ventricular failure

Nicardipine is a new slow channel calcium blocker. It has been shown to be effective in the treatment of hypertension and angina pectoris. Nine patients with mild to moderate left ventricular failure were given intravenous infusions of nicardipine and the haemodynamic effects measured. In patients receiving 20 mg of nicardipine, mean cardiac index rose to a peak 1.81 X min-1 X m-2 (64%) above the preinfusion level, stroke volume index rose by 12 ml X m-2 (35%) and heart rate rose by 16 beats X min-1 (20%). There was a significant fall in systemic vascular resistance of 50% manifested by a reduction of 22 mm Hg in systolic blood pressure (18%) and 18 mm Hg in diastolic blood pressure (22%). Pulmonary vascular resistance fell by 45%. Mean pulmonary artery pressure and capillary wedge pressure did not change significantly. This study suggests that concomitant mild to moderate left ventricular failure is not a contra-indication to nicardipine therapy in patients with angina.