Nicardipine

INDICATIONS AND USAGE I. Stable Angina Nicardipine hydrochloride capsules are indicated for the management of patients with chronic stable angina (effort-associated angina). Nicardipine hydrochloride capsules may be used alone or in combination with beta-blockers. II. Hypertension Nicardipine hydrochloride capsules are indicated for the treatment of hypertension. Nicardipine hydrochloride capsules may be used alone or in combination with other antihypertensive drugs. In administering nicardipine hydrochloride it is important to be aware of the relatively large peak to trough differences in blood pressure effect (See DOSAGE AND ADMINISTRATION ).

Mechanism of Action Nicardipine hydrochloride capsules are a calcium entry blocker (slow channel blocker or calcium ion antagonist) that inhibits the transmembrane influx of calcium ions into cardiac muscle and smooth muscle without changing serum calcium concentrations. The contractile processes of cardiac muscle and vascular smooth muscle are dependent upon the movement of extracellular calcium ions into these cells through specific ion channels. The effects of nicardipine hydrochloride capsules are more selective to vascular smooth muscle than cardiac muscle. In animal models, Nicardipine hydrochloride capsules produce relaxation of coronary vascular smooth muscle at drug levels that cause little or no negative inotropic effect.

DOSAGE AND ADMINISTRATION Angina The dose should be individually titrated for each patient beginning with 20 mg three times daily. Doses in the range of 20 to 40 mg three times a day have been shown to be effective. At least 3 days should be allowed before increasing the nicardipine hydrochloride capsuels dose to ensure achievement of steady-state plasma drug concentrations. Concomitant Use With Other Antianginal Agents Sublingual NTG may be taken as required to abort acute anginal attacks during nicardipine hydrochloride capsules therapy. Prophylactic Nitrate Therapy: nicardipine hydrochloride capsules may be safely coadministered with short- and long-acting nitrates. Beta-blockers : Nicardipine hydrochloride capsules may be safely coadministered with beta-blockers (see Drug Interactions ). Hypertension The dose of nicardipine hydrochloride capsules should be individually adjusted according to the blood pressure response beginning with 20 mg three times daily. The effective doses in clinical trials have ranged from 20 mg to 40 mg three times daily. The maximum blood pressure lowering effect occurs approximately 1 to 2 hours after dosing. To assess the adequacy of blood pressure response, the blood pressure should be measured at trough (8 hours after dosing). Because of the prominent peak effects of nicardipine, blood pressure should be measured 1 to 2 hours after dosing, particularly during initiation of therapy (see PRECAUTIONS : Blood Pressure , INDICATIONS AND USAGE , CLINICAL PHARMACOLOGY , Effects in Hypertension ). At least 3 days should be allowed before increasing the nicardipine hydrochloride capsules dose to ensure achievement of steady-state plasma drug concentrations. Concomitant Use With Other Antihypertensive Agents 1. Diuretics: nicardipine hydrochloride capsules may be safety coadministered with thiazide diuretics. 2. Beta-blockers: nicardipine hydrochloride capsules may be safely coadministered with beta-blocker (see PRECAUTIONS , Drug Interactions ). Special Patient Population Renal Insufficiency Although there is no evidence that nicardipine hydrochloride capsules impair renal function, careful dose titration beginning with 20 mg tid is advised (see PRECAUTIONS ). Hepatic Insufficiency Nicardipine hydrochloride capsules should be administered cautiously in patients with severely impaired hepatic function. A suggested starting dose of 20 mg twice a day is advised with individual titration based on clinical findings maintaining the twice a day schedule (see PRECAUTIONS ). Congestive Heart Failure Caution is advised when titrating nicardipine hydrochloride capsules dosage in patients with congestive heart failure (see WARNINGS ).

ADVERSE REACTIONS In multiple-dose U.S. and foreign controlled short-term (up to 3 months) studies 1910 patients received nicardipine hydrochloride capsules alone or in combination with other drugs. In these studies adverse events were reported spontaneously; adverse experiences were generally not serious but occasionally required dosage adjustment and about 10% of patients left the studies prematurely because of them. Peak responses were not observed to be associated with adverse effects during clinical trials, but physicians should be aware that adverse effects associated with decreases in blood pressure (tachycardia, hypotension, etc.) could occur around the time of the peak effect. Most adverse effects were expected consequences of the vasodilator effects of nicardipine hydrochloride capsules. Angina The incidence rates of adverse effects in anginal patients were derived from multicenter, controlled clinical trials. Following are the rates of adverse effects for nicardipine hydrochloride capsules (n=520) and placebo (n=310), respectively, that occurred in 0.4% of patients or more. These represent events considered probably drug-related by the investigator (except for certain cardiovascular events that were recorded in a different category). Where the frequency of adverse effects for nicardipine hydrochloride capsules and placebo is similar, causal relationship is uncertain. The only dose-related effects were pedal edema and increased angina. Table 2 Percent of Patients With Adverse Effects in Controlled Studies (Incidence of Discontinuations Shown in Parentheses) Adverse Experience NICARDIPINE HYDROCHLORIDE CAPSULES (n= 520) PLACEBO (n= 310) Pedal Edema 7.1 (0) 0.3 (0) Dizziness 6.9 (1.2) 0.6 (0) Headache 6.4 (0.6) 2.6 (0) Asthenia 5.8 (0.4) 2.6 (0) Flushing 5.6 (0.4) 1.0 (0) Increased Angina 5.6 (3.5) 4.2 (1.9) Palpitations 3.3 (0.4) 0.0 (0) Nausea 1.9 (0) 0.3 (0) Dyspepsia 1.5 (0.6) 0.6 (0.3) Dry Mouth 1.4 (0) 0.3 (0) Somnolence 1.4 (0) 1.0 (0) Rash 1.2 (0.2) 0.3 (0) Tachycardia 1.2 (0.2) 0.6 (0) Myalgia 1.0 (0) 0.0 (0) Other Edema 1.0 (0) 0.0 (0) Paresthesia 1.0 (0.2) 0.3 (0) Sustained Tachycardia 0.8 (0.6) 0.0 (0) Syncope 0.8 (0.2) 0.0 (0) Constipation 0.6 (0.2) 0.6 (0) Dyspnea 0.6 (0) 0.0 (0) Abnormal ECG 0.6 (0.6) 0.0 (0) Malaise 0.6 (0) 0.0 (0) Nervousness 0.6 (0) 0.3 (0) Tremor 0.6 (0) 0.0 (0) In addition, adverse events were observed that are not readily distinguishable from the natural history of the atherosclerotic vascular disease in these patients. Adverse events in this category each occurred in <0.4% of patients receiving nicardipine hydrochloride capsules and included myocardial infarction, atrial fibrillation, exertional hypotension, pericarditis, heart block, cerebral ischemia, and ventricular tachycardia. It is possible that some of these events were drug-related. Hypertension The incidence rates of adverse effects in hypertensive patients were derived from multicenter, controlled clinical trials. Following are the rates of adverse effects for nicardipine hydrochloride capsules (n= 1390) and placebo (n= 211), respectively, that occurred in 0.4% of patients or more. These represent events considered probably drug-related by the investigator. Where the frequency of adverse effects for nicardipine hydrochloride capsules and placebo is similar, causal relationship is uncertain. The only dose-related effect was pedal edema. Table 3 Percent of Patients with Adverse Effects in Controlled Studies (Incidence of discontinuations shown in parentheses) Adverse Experience NICARDIPINE HYDROCHLORIDE CAPSULES (n = 1390) PLACEBO (n = 211) Flushing 9.7 (2.1) 2.8 (0) Headache 8.2 (2.6) 4.7 (0) Pedal Edema 8.0 (1.8) 0.9 (0) Asthenia 4.2 (1.7) 0.5 (0) Palpitations 4.1 (1.0) 0.0 (0) Dizziness 4.0 (1.8) 0.0 (0) Tachycardia 3.4 (1.2) 0.5 (0) Nausea 2.2 (0.9) 0.9 (0) Somnolence 1.1 (0.1) 0.0 (0) Dyspepsia 0.8 (0.3) 0.5 (0) Insomnia 0.6 (0.1) 0.0 (0) Malaise 0.6 (0.1) 0.0 (0) Other Edema 0.6 (0.3) 1.4 (0) Abnormal Dreams 0.4 (0)

WARNINGS Increased Angina About 7% of patients in short-term, placebo-controlled angina trials have developed increased frequency, duration or severity of angina on starting nicardipine hydrochloride capsules or at the time of dosage increases, compared with 4% of patients on placebo. Comparisons with beta-blockers also show a greater frequency of increased angina, 4% vs 1%. The mechanism of this effect has not been established (see ADVERSE REACTIONS ). Use in Patients With Congestive Heart Failure Although preliminary hemodynamic studies in patients with congestive heart failure have shown that nicardipine hydrochloride capsules reduced afterload without impairing myocardial contractility, it has a negative inotropic effect in vitro and in some patients. Caution should be exercised when using the drug in congestive heart failure patients, particularly in combination with a beta-blocker. Beta-Blocker Withdrawal Nicardipine hydrochloride capsules are not a beta-blocker and therefore gives no protection against the dangers of abrupt beta-blocker withdrawal; any such withdrawal should be by gradual reduction of the dose of beta-blocker, preferably over 8 to 10 days.

CONTRAINDICATIONS Nicardipine hydrochloride capsules are contraindicated in patients with hypersensitivity to the drug. Because part of the effect of nicardipine hydrochloride capsules are secondary to reduced afterload, the drug is also contraindicated in patients with advanced aortic stenosis. Reduction of diastolic pressure in these patients may worsen rather than improve myocardial oxygen balance.

OVERDOSAGE Overdosage with a 600-mg single dose (15 to 30 times normal clinical dose) has been reported. Marked hypotension (blood pressure unobtainable) and bradycardia (heart rate 20 bpm in normal sinus rhythm) occurred, along with drowsiness, confusion and slurred speech. Supportive treatment with a vasopressor resulted in gradual improvement with normal vital signs approximately 9 hours posttreatment. Based on results obtained in laboratory animals, overdosage may cause systemic hypotension, bradycardia (following initial tachycardia) and progressive atrioventricular conduction block. Reversible hepatic function abnormalities and sporadic focal hepatic necrosis were noted in some animal species receiving very large doses of nicardipine. For treatment of overdose standard measures (for example, evacuation of gastric contents, elevation of extremities, attention to circulating fluid volume, and urine output) including monitoring of cardiac and respiratory functions should be implemented. The patient should be positioned so as to avoid cerebral anoxia. Frequent blood pressure determinations are essential. Vasopressors are clinically indicated for patients exhibiting profound hypotension. Intravenous calcium gluconate may help reverse the effects of calcium entry blockade.