Nicardipine for stable angina pectoris

Severe neuromuscular complications possibly associated with amlodipine

OBJECTIVE

To document a case of severe, progressive myopathy, myalgias, arthralgias, and weakness possibly caused by amlodipine in a patient with benign essential hypertension.

CASE SUMMARY

A 52-year-old white woman with asthma and newly diagnosed hypertension was initiated on zafirlukast therapy for asthma and amlodipine therapy for hypertension. Two months later, the patient reported severe, generalized muscle and joint pain, muscle stiffness, and weakness. The zafirlukast was discontinued without resolution of symptoms. Laboratory tests revealed an elevated C-reactive protein. The amlodipine dosage was increased. Her symptoms persisted and further laboratory tests revealed a positive anti-nuclear antibody screen, and negative single- and double-stranded DNA antibody tests. After another amlodipine dosage increase, the patient experienced a sudden onset of left-sided facial numbness, facial weakness, and a severe headache.The patient was admitted to rule out a possible cerebrovascular event or a metabolic neurologic process. Magnetic resonance imaging showed no abnormalities. The patient discontinued the amlodipine and reported complete resolution of the neurologic symptoms after 4 days. One month later, zafirlukast was reinitiated without a return of symptoms.

CONCLUSIONS

Amlodipine was not initially suspected as a cause of these symptoms because these effects are not commonly associated with amlodipine therapy. However, due to the temporal relationship and progression of symptoms with increasing amlodipine dosage, drug-related causes were eventually explored. Review of the medical literature suggests myalgias and arthralgias may be adverse effects common to dihydropyridine calcium-channel antagonists.

Nicardipine. A review of its pharmacology and therapeutic efficacy in older patients

Nicardipine is a second generation dihydropyridine calcium antagonist which selectively inhibits vascular smooth muscle contraction. In elderly patients, the drug has demonstrated clinical efficacy in the management of hypertension, angina pectoris and ischaemia-related cerebrovascular disease. In particular, nicardipine effectively controls blood pressure in elderly hypertensive patients with or without coexistent disease. In noncomparative trials, a regimen containing nicardipine has been associated with an improvement of symptoms in hypertensive patients with concurrent coronary artery, cerebrovascular or peripheral vascular disease, while in essentially 'healthy' elderly hypertensive patients, nicardipine monotherapy has resulted in improved indices of mobility and cognitive function. As yet, however, there is no evidence that nicardipine (and/or other calcium channel antagonists) decreases cardiovascular morbidity and mortality in elderly patients, as has been demonstrated for more established antihypertensive therapies, namely diuretics and/or beta-blockers. The pharmacokinetic properties of nicardipine in elderly hypertensive patients appear to be similar to those in younger patients. The main adverse events associated with nicardipine in the elderly are related to the vasodilator properties of the drug and include pedal oedema, headache and flushing. However, the drug does not exacerbate spontaneous postural hypotension in the elderly, nor does it adversely affect the coronary artery disease risk profile, even in patients with type II diabetes mellitus. In summary, widespread clinical experience in the elderly indicates that nicardipine monotherapy or a regimen containing nicardipine is useful for the treatment of hypertension, particularly in patients with coexistent coronary artery, cerebrovascular or peripheral vascular disease. Nicardipine monotherapy has also demonstrated efficacy in angina pectoris and shown promise in the management of ischaemia-related cerebrovascular diseases, notably subarachnoid haemorrhage.

Haemodynamic and radionuclide effects of amlodipine in coronary artery disease

1. The haemodynamic and radionuclide effects of a new long-acting slow-calcium channel blocking agent, amlodipine, were evaluated in 32 patients with coronary artery disease. 2. Haemodynamic measurements in 24 patients were made at rest and 10 to 15 min after 20 mg i.v. amlodipine. Amlodipine significantly reduced systemic arterial blood pressure and vascular resistance index with an increased heart rate and augmented cardiac index. Cardiac stroke volume index rose and stroke work fell without change in pulmonary artery occluded pressure (PAOP). 3. The exercise effects were determined by comparison of measurements during 4 min of supine bicycle exercise at a fixed workload before and after drug treatment. During dynamic exercise, amlodipine reduced systemic arterial pressure and vascular resistance index. Exercise cardiac index, stroke volume index and heart rate were higher. The left ventricular filling pressure was significantly reduced. 4. Radionuclide parameters were studied in 16 patients at rest and on exercise; ejection fraction was unaltered following amlodipine. 5. Pre-therapy haemodynamic values correlated with response following amlodipine for resting mean blood pressure, systemic vascular resistance and exercise PAOP. 6. Thus, the immediate impact of amlodipine in stable coronary artery disease was to reduce left ventricular afterload and thereby improve cardiac pumping performance.

Randomized double-blind comparison of side effects of nicardipine and nifedipine in angina pectoris. The Nicardipine Investigators Group

Nicardipine and nifedipine are structurally similar dihydropyridine calcium channel blockers with demonstrated efficacy in the treatment of stable angina pectoris. The present study was a prospective randomized trial designed to evaluate the relative incidence of dizziness, flushing, headache, pedal edema, and palpitations during use of these drugs in patients with angina pectoris. Of 250 patients who entered into the comparative treatment part of the study, 140 patients were susceptible to developing symptoms to nifedipine as identified during a 1-month open-label treatment with nifedipine. These patients were compared with a parallel cohort of 110 patients, who were identified during the same open-label period, but remained mostly asymptomatic. After a 1-week washout of nifedipine, equal numbers of patients in each cohort began an 8-week period of randomized, double-blind treatment with nifedipine (20 mg three times daily) or nicardipine (30 mg three times daily). Patients who experienced these symptoms during the open-label nifedipine treatment had a higher incidence of the same symptoms during the blinded treatment regimen. Nicardipine-treated patients had a lower incidence of each of the symptoms than did the nifedipine-treated patients. Statistically significant differences were reported for dizziness, the most common of the side effects. Patients who were free of these symptoms in the open-label period usually remained free of them in the blinded comparison. However, even among those free of dizziness during the open-label nifedipine treatment, more patients reported experiencing dizziness in the blinded phase from nifedipine than from nicardipine (18% vs 6%; p = 0.02).

Acute pharmacokinetic and hemodynamic effects of intravenous bolus dosing of nicardipine

The antihypertensive effects, duration of action, and pharmacokinetics of intravenous bolus doses of nicardipine were investigated in a series of patients with mild-to-moderate hypertension. Patients with a supine diastolic blood pressure between 95 and 114 mm Hg and a heart rate less than 90 beats/min who received no other antihypertensive medications were included in the study. On separate study days, single intravenous bolus doses of 0.125, 0.25, 0.5, 1, 3, 5, and 7 mg of nicardipine were administered over a 2-minute period. Blood pressure and heart rate were measured for 6 hours after an intravenous bolus of nicardipine was given, and serum nicardipine levels were measured throughout the study. Although the antihypertensive effect occurred immediately during the bolus infusion, peak average decreases in systolic and diastolic pressure ranged from 20 to 25 and 15 to 44 mm Hg, respectively, and occurred 2.5 +/- 0.6 minutes after infusion. Heart rate increased by 12 to 40 beats/min during the peak effect. The mean duration of action after an intravenous bolus dose was 24 +/- 5 minutes. A dose-response relationship was observed, as both nicardipine dosage and plasma nicardipine concentration correlated with reduction in blood pressure. These data indicate that bolus administration of nicardipine may provide a practical approach for the rapid parenteral treatment of hypertensive states.

Efficacy of nicardipine in angina pectoris

The dose-related efficacy and safety of nicardipine, a new calcium antagonist of the dihydropyridine class, was assessed by exercise tolerance testing in a randomized, double-blinded, placebo-controlled study in 19 patients with chronic, stable effort angina pectoris. Four patients were assigned to each of four treatment sequences receiving nicardipine three times daily in an extended Latin-Square study design. An increase in total exercise capacity, time to onset of angina and time to 1 mm ST segment depression was observed with nicardipine 90 mg/day compared to placebo (P less than .05). Gradual upward dose titration in 30 mg/day increments starting from 30 mg/day appeared to produce maximal increase in exercise capacity. Two patients developed adverse side effects attributable to the drug when administered nicardipine 90 mg/day directly from placebo.

Usefulness of nicardipine as monotherapy for chronic, stable angina

Using a double-blind, Latin square protocol designed to detect dose response, nicardipine hydrochloride, a new calcium antagonist, was studied as monotherapy for stable exertional angina. Eighty-one patients were enrolled in the trial and 62 patients were included in greater than or equal to 1 primary efficacy analyses. Patients received 1 to 2 weeks of placebo run-in, then 5 weeks of treatment with placebo and with 10, 20 and 30 mg of nicardipine given 3 times daily. Patients completed symptom diaries, were monitored with 24-hour electrocardiographic Holter monitors and underwent serial exercise treadmill tests. By 1 hour, 10, 20 and 30 mg of nicardipine administered 3 times daily produced statistically significant, dose-related improvements in all key exercise parameters, which persisted at the 4-hour evaluation. The systolic blood pressure at rest and during exercise decreased, but the pulse slightly increased. The peak rate-pressure product was unchanged. The side effects were not severe. Nicardipine hydrochloride is an effective, well-tolerated medication for the treatment of stable exertional angina, and is a good alternative to currently available calcium antagonists.

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.

Comparison of nicardipine and verapamil in the management of chronic stable angina

Twenty-two patients with stable angina were studied in a randomised double-blind, placebo-controlled crossover trial to compare the antianginal effects of nicardipine (30 mg) and verapamil (120 mg), each given three times a day. Efficacy was assessed using treadmill exercise testing and 24-hour ambulatory electrocardiographic monitoring performed after an initial 2-week placebo phase and at the end of each 4-week active treatment period. Exercise time (mean +/- standard error of mean) increased from 7.4 +/- 0.5 min on placebo to 8.4 +/- 0.7 min on nicardipine (P less than 0.05) and to 9.9 +/- 0.7 min on verapamil (P less than 0.001). Resting heart rate was decreased by verapamil (P less than 0.002) and increased by nicardipine (P less than 0.02). Exercise heart rate was increased on nicardipine (P less than 0.005) but heart rate gain was higher on verapamil (P less than 0.01). Blood pressure and peak ST segment depression were unaltered by either drug but the time to 1 mm ST segment depression increased on both drugs. Ambulatory heart rates were lower on verapamil than on nicardipine and patient subjective preference was in favour of verapamil. This study confirms that both nicardipine and verapamil improve exercise capacity, but verapamil produces a greater improvement in exercise tolerance and indices of myocardial ischaemia whilst nicardipine is associated with an increase in the number of episodes of ST segment depression on ambulatory monitoring.

Calcium channel blockers in systemic hypertension

Alterations in transmembrane flux of calcium ions may be playing a role in the pathophysiology of systemic hypertension. Calcium channel blockers have been shown to be effective antihypertensive drugs with excellent safety profiles. They are efficacious in the long term treatment of systemic hypertension in all population subgroups, and have special applicability for treating patients with hypertensive urgencies and individuals with concomitant diseases such as angina pectoris and arrhythmias.

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.

Usefulness of nicardipine for angina pectoris

Nicardipine treatment has been evaluated in patients with chronic stable effort angina or with angina at rest due to coronary spasm. Acute studies in patients with effort angina suggest a very favorable hemodynamic profile characterized by coronary vasodilatation and reduction in determinants of myocardial oxygen demand. Both open and controlled trials in patients with effort angina show that long-term oral administration increases exercise time and time to onset of 1 mm ST-segment depression and decreases angina frequency. With treatment for up to 6 months, antiischemic effects were maintained without serious adverse reactions. Other studies indicate that nicardipine is generally comparable to propranolol and nifedipine in prolonging exercise time and time to onset of ST-segment depression. Nicardipine, however, does not depress heart rate at rest, and maximal exercise workload is higher with nicardipine than with either placebo or propranolol. In a controlled study of patients with angina at rest due to coronary spasm, nicardipine decreased angina frequency and nitroglycerin consumption by approximately 80%. Episodes of symptomatic and asymptomatic ST-segment shift, as recorded by ambulatory electrocardiographic monitoring, showed a trend to decrease in number. Nicardipine appeared similarly effective in patients with coronary spasm superimposed on significant coronary disease and with spasm in the absence of significant coronary disease. Nicardipine appears to be safe and effective in the management of patients with angina pectoris.

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.