Generic Name: AMLODIPINE BESYLATE
Brand Name: Amlodipine Besylate
- Substance Name(s):
- AMLODIPINE BESYLATE
7 Do not exceed doses greater than 20 mg daily of simvastatin. (7.2) 7.1 Impact of Other Drugs on Amlodipine CYP3A Inhibitors Co-administration with CYP3A inhibitors (moderate and strong) results in increased systemic exposure to amlodipine and may require dose reduction. Monitor for symptoms of hypotension and edema when amlodipine is co-administered with CYP3A inhibitors to determine the need for dose adjustment [see CLINICAL PHARMACOLOGY (12.3)]. CYP3A Inducers No information is available on the quantitative effects of CYP3A inducers on amlodipine. Blood pressure should be closely monitored when amlodipine is co-administered with CYP3A inducers. Sildenafil Monitor for hypotension when sildenafil is co-administered with amlodipine [see CLINICAL PHARMACOLOGY (12.2)]. 7.2 Impact of Amlodipine on Other Drugs Simvastatin Co-administration of simvastatin with amlodipine increases the systemic exposure of simvastatin. Limit the dose of simvastatin in patients on amlodipine to 20 mg daily [see CLINICAL PHARMACOLOGY (12.3)]. Immunosuppressants Amlodipine may increase the systemic exposure of cyclosporine or tacrolimus when co-administered. Frequent monitoring of trough blood levels of cyclosporine and tacrolimus is recommended and adjust the dose when appropriate [see CLINICAL PHARMACOLOGY (12.3)].
10 Overdosage might be expected to cause excessive peripheral vasodilation with marked hypotension and possibly a reflex tachycardia. In humans, experience with intentional overdosage of amlodipine is limited. Single oral doses of amlodipine maleate equivalent to 40 mg amlodipine/kg and 100 mg amlodipine/kg in mice and rats, respectively, caused deaths. Single oral amlodipine maleate doses equivalent to 4 or more mg amlodipine/kg or higher in dogs (11 or more times the maximum recommended human dose on a mg/m2 basis) caused a marked peripheral vasodilation and hypotension. If massive overdose should occur, initiate active cardiac and respiratory monitoring. Frequent blood pressure measurements are essential. Should hypotension occur, provide cardiovascular support including elevation of the extremities and the judicious administration of fluids. If hypotension remains unresponsive to these conservative measures, consider administration of vasopressors (such as phenylephrine) with attention to circulating volume and urine output. As amlodipine is highly protein bound, hemodialysis is not likely to be of benefit.
11 Amlodipine besylate is the besylate salt of amlodipine, a long-acting calcium channel blocker. Amlodipine besylate is chemically described as 3-Ethyl-5-methyl (±)-2-[(2-aminoethoxy)methyl]-4-(2-chlorophenyl)-1,4-dihydro-6-methyl-3,5-pyridinedicarboxylate, monobenzenesulphonate. Its empirical formula is C20H25ClN2O5•C6H6O3S, and its structural formula is: Amlodipine besylate is a white crystalline powder with a molecular weight of 567.1. It is slightly soluble in water and sparingly soluble in ethanol. Amlodipine besylate tablets USP are formulated as white to off-white tablets equivalent to 2.5 mg, 5 mg and 10 mg of amlodipine for oral administration. In addition to the active ingredient, amlodipine besylate, each tablet contains the following inactive ingredients: dibasic calcium phosphate anhydrous, magnesium stearate, microcrystalline cellulose and sodium starch glycolate. Amlodipine Besylate
14 14.1 Effects in Hypertension Adult Patients The antihypertensive efficacy of amlodipine has been demonstrated in a total of 15 double-blind, placebo-controlled, randomized studies involving 800 patients on amlodipine and 538 on placebo. Once daily administration produced statistically significant placebo-corrected reductions in supine and standing blood pressures at 24 hours postdose, averaging about 12/6 mmHg in the standing position and 13/7 mmHg in the supine position in patients with mild to moderate hypertension. Maintenance of the blood pressure effect over the 24-hour dosing interval was observed, with little difference in peak and trough effect. Tolerance was not demonstrated in patients studied for up to 1 year. The 3 parallel, fixed dose, dose response studies showed that the reduction in supine and standing blood pressures was dose-related within the recommended dosing range. Effects on diastolic pressure were similar in young and older patients. The effect on systolic pressure was greater in older patients, perhaps because of greater baseline systolic pressure. Effects were similar in black patients and in white patients. Pediatric Patients Two hundred sixty-eight hypertensive patients aged 6 to 17 years were randomized first to amlodipine 2.5 or 5 mg once daily for 4 weeks and then randomized again to the same dose or to placebo for another 4 weeks. Patients receiving 2.5 mg or 5 mg at the end of 8 weeks had significantly lower systolic blood pressure than those secondarily randomized to placebo. The magnitude of the treatment effect is difficult to interpret, but it is probably less than 5 mmHg systolic on the 5 mg dose and 3.3 mmHg systolic on the 2.5 mg dose. Adverse events were similar to those seen in adults. 14.2 Effects in Chronic Stable Angina The effectiveness of 5 to 10 mg/day of amlodipine in exercise-induced angina has been evaluated in 8 placebo-controlled, double-blind clinical trials of up to 6 weeks duration involving 1038 patients (684 amlodipine, 354 placebo) with chronic stable angina. In 5 of the 8 studies, significant increases in exercise time (bicycle or treadmill) were seen with the 10 mg dose. Increases in symptom-limited exercise time averaged 12.8% (63 sec) for amlodipine 10 mg, and averaged 7.9% (38 sec) for amlodipine 5 mg. Amlodipine 10 mg also increased time to 1 mm ST segment deviation in several studies and decreased angina attack rate. The sustained efficacy of amlodipine in angina patients has been demonstrated over long-term dosing. In patients with angina, there were no clinically significant reductions in blood pressures (4/1 mmHg) or changes in heart rate (+0.3 bpm). 14.3 Effects in Vasospastic Angina In a double-blind, placebo-controlled clinical trial of 4 weeks duration in 50 patients, amlodipine therapy decreased attacks by approximately 4/week compared with a placebo decrease of approximately 1/week (p<0.01). Two of 23 amlodipine and 7 of 27 placebo patients discontinued from the study due to lack of clinical improvement. 14.4 Effects in Documented Coronary Artery Disease In PREVENT, 825 patients with angiographically documented coronary artery disease were randomized to amlodipine (5 to 10 mg once daily) or placebo and followed for 3 years. Although the study did not show significance on the primary objective of change in coronary luminal diameter as assessed by quantitative coronary angiography, the data suggested a favorable outcome with respect to fewer hospitalizations for angina and revascularization procedures in patients with CAD. CAMELOT enrolled 1318 patients with CAD recently documented by angiography, without left main coronary disease and without heart failure or an ejection fraction <40%. Patients (76% males, 89% Caucasian, 93% enrolled at U.S. sites, 89% with a history of angina, 52% without PCI, 4% with PCI and no stent, and 44% with a stent) were randomized to double-blind treatment with either amlodipine (5 to 10 mg once daily) or placebo in addition to standard care that included aspirin (89%), statins (83%), beta-blockers (74%), nitroglycerin (50%), anti-coagulants (40%), and diuretics (32%), but excluded other calcium channel blockers. The mean duration of follow-up was 19 months. The primary endpoint was the time to first occurrence of one of the following events: hospitalization for angina pectoris, coronary revascularization, myocardial infarction, cardiovascular death, resuscitated cardiac arrest, hospitalization for heart failure, stroke/TIA, or peripheral vascular disease. A total of 110 (16.6%) and 151 (23.1%) first events occurred in the amlodipine and placebo groups, respectively, for a hazard ratio of 0.691 (95% CI: 0.540 to 0.884, p = 0.003). The primary endpoint is summarized in Figure 1 below. The outcome of this study was largely derived from the prevention of hospitalizations for angina and the prevention of revascularization procedures (see Table 1). Effects in various subgroups are shown in Figure 2. In an angiographic substudy (n=274) conducted within CAMELOT, there was no significant difference between amlodipine and placebo on the change of atheroma volume in the coronary artery as assessed by intravascular ultrasound. Figure 1 – Kaplan-Meier Analysis of Composite Clinical Outcomes for Amlodipine versus Placebo Figure 2 – Effects on Primary Endpoint of Amlodipine versus Placebo across Sub-Groups Table 1 below summarizes the significant composite endpoint and clinical outcomes from the composites of the primary endpoint. The other components of the primary endpoint including cardiovascular death, resuscitated cardiac arrest, myocardial infarction, hospitalization for heart failure, stroke/TIA, or peripheral vascular disease did not demonstrate a significant difference between amlodipine and placebo. Table 1. Incidence of Significant Clinical Outcomes for CAMELOT Clinical Outcomes N (%) Amlodipine ( N = 663 ) Placebo ( N = 655 ) Risk Reduction ( p – value ) Composite CV Endpoint 110 ( 16 . 6 ) 151 ( 23 . 1 ) 31 % ( 0 . 003 ) Hospitalization for AnginaTotal patients with these events 51 (7.7) 84 (12.8) 42% (0.002) Coronary Revascularization 78 (11.8) 103 (15.7) 27% (0.033) 14.5 Studies in Patients with Heart Failure Amlodipine has been compared to placebo in four 8 to 12 week studies of patients with NYHA Class II/III heart failure, involving a total of 697 patients. In these studies, there was no evidence of worsened heart failure based on measures of exercise tolerance, NYHA classification, symptoms, or left ventricular ejection fraction. In a long-term (follow-up at least 6 months, mean 13.8 months) placebo- controlled mortality/morbidity study of amlodipine 5 to 10 mg in 1153 patients with NYHA Classes III (n=931) or IV (n=222) heart failure on stable doses of diuretics, digoxin, and ACE inhibitors, amlodipine had no effect on the primary endpoint of the study which was the combined endpoint of all-cause mortality and cardiac morbidity (as defined by life-threatening arrhythmia, acute myocardial infarction, or hospitalization for worsened heart failure), or on NYHA classification, or symptoms of heart failure. Total combined all-cause mortality and cardiac morbidity events were 222/571 (39%) for patients on amlodipine and 246/583 (42%) for patients on placebo; the cardiac morbid events represented about 25% of the endpoints in the study. Another study (PRAISE-2) randomized patients with NYHA Class III (80%) or IV (20%) heart failure without clinical symptoms or objective evidence of underlying ischemic disease, on stable doses of ACE inhibitors (99%), digitalis (99%), and diuretics (99%), to placebo (n=827) or amlodipine (n=827) and followed them for a mean of 33 months. There was no statistically significant difference between amlodipine and placebo in the primary endpoint of all-cause mortality (95% confidence limits from 8% reduction to 29% increase on amlodipine). With amlodipine there were more reports of pulmonary edema. Figure 1 – Kaplan-Meier Analysis of Composite Clinical Outcomes for Amlodipine versus Placebo Figure 2 – Effects on Primary Endpoint of Amlodipine versus Placebo across Sub-Groups
16 /STORAGE AND HANDLING 2.5 mg Tablets Amlodipine Besylate Tablets USP, 2.5 mg – (amlodipine besylate equivalent to 2.5 mg of amlodipine per tablet) are supplied as white to off-white, diamond shaped, flat faced, beveled edge tablets, debossed with ‘LU’ on one side and ‘H11’ on the other side and supplied as follows: NDC 68180-750-09 Bottles of 90 5 mg Tablets Amlodipine Besylate Tablets USP, 5 mg – (amlodipine besylate equivalent to 5 mg of amlodipine per tablet) are supplied as white to off-white, elongated octagonal, flat faced, beveled edge tablets, debossed with ‘LU’ on one side and ‘H12’ on the other side and supplied as follows: NDC 68180-751-09 Bottles of 90 NDC 68180-751-17 Bottles of 300 NDC 68180-751-03 Bottles of 1000 10 mg Tablets Amlodipine Besylate Tablets USP, 10 mg – (amlodipine besylate equivalent to 10 mg of amlodipine per tablet) are supplied as white to off-white, round, flat faced, beveled edge tablets, debossed with ‘LU’ on one side and ‘H13’ on the other side and supplied as follows: NDC 68180-752-09 Bottles of 90 NDC 68180-752-03 Bottles of 1000 Storage Store at 20° to 25°C (68° to 77°F) [see USP controlled room temperature] and dispense in tight, light-resistant containers (USP). Manufactured for: Lupin Pharmaceuticals, Inc. Baltimore, Maryland 21202 United States MADE IN INDIA. Revised: December 2015 ID#: 243431
8.5 Geriatric Use Clinical studies of amlodipine did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. Elderly patients have decreased clearance of amlodipine with a resulting increase of AUC of approximately 40 to 60%, and a lower initial dose may be required [see DOSAGE AND ADMINISTRATION (2.1)] .
DOSAGE FORMS AND STRENGTHS
3 Tablets: 2.5 mg, 5 mg, and 10 mg (3) Tablets: 2.5 mg white to off-white, diamond shaped, flat faced, beveled edge tablets, debossed with ‘LU’ on one side and ‘H11’ on the other side. Tablets: 5 mg white to off-white, elongated octagonal, flat faced, beveled edge tablets, debossed with ‘LU’ on one side and ‘H12’ on the other side. Tablets: 10 mg white to off-white, round, flat faced, beveled edge tablets, debossed with ‘LU’ on one side and ‘H13’ on the other side.
MECHANISM OF ACTION
12.1 Mechanism of Action Amlodipine is a dihydropyridine calcium antagonist (calcium ion antagonist or slow-channel blocker) that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle. Experimental data suggest that amlodipine binds to both dihydropyridine and nondihydropyridine binding sites. 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. Amlodipine inhibits calcium ion influx across cell membranes selectively, with a greater effect on vascular smooth muscle cells than on cardiac muscle cells. Negative inotropic effects can be detected in vitro but such effects have not been seen in intact animals at therapeutic doses. Serum calcium concentration is not affected by amlodipine. Within the physiologic pH range, amlodipine is an ionized compound (pKa=8.6), and its kinetic interaction with the calcium channel receptor is characterized by a gradual rate of association and dissociation with the receptor binding site, resulting in a gradual onset of effect. Amlodipine is a peripheral arterial vasodilator that acts directly on vascular smooth muscle to cause a reduction in peripheral vascular resistance and reduction in blood pressure. The precise mechanisms by which amlodipine relieves angina have not been fully delineated, but are thought to include the following: Exertional Angina In patients with exertional angina, amlodipine reduces the total peripheral resistance (afterload) against which the heart works and reduces the rate pressure product, and thus myocardial oxygen demand, at any given level of exercise. Vasospastic Angina Amlodipine has been demonstrated to block constriction and restore blood flow in coronary arteries and arterioles in response to calcium, potassium epinephrine, serotonin, and thromboxane A2 analog in experimental animal models and in human coronary vessels in vitro. This inhibition of coronary spasm is responsible for the effectiveness of amlodipine in vasospastic (Prinzmetal’s or variant) angina.
INDICATIONS AND USAGE
1 Amlodipine besylate tablets USP are calcium channel blocker and may be used alone or in combination with other antihypertensive and antianginal agents for the treatment of: •Hypertension (1.1) о Amlodipine besylate tablets USP are indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. •Coronary Artery Disease (1.2) о Chronic Stable Angina о Vasospastic Angina (Prinzmetal’s or Variant Angina) о Angiographically Documented Coronary Artery Disease in patients without heart failure or an ejection fraction < 40% 1.1 Hypertension Amlodipine besylate tablets USP are indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes including amlodipine besylate. Control of high blood pressure should be part of comprehensive cardiovascular risk management, including, as appropriate, lipid control, diabetes management, antithrombotic therapy, smoking cessation, exercise, and limited sodium intake. Many patients will require more than one drug to achieve blood pressure goals. For specific advice on goals and management, see published guidelines, such as those of the National High Blood Pressure Education Program's Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC). Numerous antihypertensive drugs, from a variety of pharmacologic classes and with different mechanisms of action, have been shown in randomized controlled trials to reduce cardiovascular morbidity and mortality, and it can be concluded that it is blood pressure reduction, and not some other pharmacologic property of the drugs, that is largely responsible for those benefits. The largest and most consistent cardiovascular outcome benefit has been a reduction in the risk of stroke, but reductions in myocardial infarction and cardiovascular mortality also have been seen regularly. Elevated systolic or diastolic pressure causes increased cardiovascular risk, and the absolute risk increase per mmHg is greater at higher blood pressures, so that even modest reductions of severe hypertension can provide substantial benefit. Relative risk reduction from blood pressure reduction is similar across populations with varying absolute risk, so the absolute benefit is greater in patients who are at higher risk independent of their hypertension (for example, patients with diabetes or hyperlipidemia), and such patients would be expected to benefit from more aggressive treatment to a lower blood pressure goal. Some antihypertensive drugs have smaller blood pressure effects (as monotherapy) in black patients, and many antihypertensive drugs have additional approved indications and effects (e.g., on angina, heart failure, or diabetic kidney disease). These considerations may guide selection of therapy. Amlodipine besylate tablets USP may be used alone or in combination with other antihypertensive agents. 1.2 Coronary Artery Disease (CAD) Chronic Stable Angina Amlodipine besylate tablets USP are indicated for the symptomatic treatment of chronic stable angina. Amlodipine besylate tablets USP may be used alone or in combination with other antianginal agents. Vasospastic Angina (Prinzmetal's or Variant Angina) Amlodipine besylate tablets USP are indicated for the treatment of confirmed or suspected vasospastic angina. Amlodipine besylate tablets USP may be used as monotherapy or in combination with other antianginal agents. Angiographically Documented CAD In patients with recently documented CAD by angiography and without heart failure or an ejection fraction <40%, amlodipine besylate tablets USP are indicated to reduce the risk of hospitalization for angina and to reduce the risk of a coronary revascularization procedure.
8.4 Pediatric Use Amlodipine besylate (2.5 to 5 mg daily) is effective in lowering blood pressure in patients 6 to 17 years [see CLINICAL STUDIES (14.1)]. Effect of Amlodipine besylate on blood pressure in patients less than 6 years of age is not known.
8.1 Pregnancy Pregnancy Category C There are no adequate and well-controlled studies in pregnant women. Amlodipine should be used during pregnancy only if the potential benefit justifies the risk to the fetus. No evidence of teratogenicity or other embryo/fetal toxicity was found when pregnant rats and rabbits were treated orally with amlodipine maleate at doses up to 10 mg amlodipine/kg/day (respectively, 8 times2 and 23 times2 the maximum recommended human dose of 10 mg on a mg/m2 basis) during their respective periods of major organogenesis. However, litter size was significantly decreased (by about 50%) and the number of intrauterine deaths was significantly increased (about 5-fold) in rats receiving amlodipine maleate at a dose equivalent to 10 mg amlodipine/kg/day for 14 days before mating and throughout mating and gestation. Amlodipine maleate has been shown to prolong both the gestation period and the duration of labor in rats at this dose. 2Based on patient weight of 50 kg.
8.3 Nursing Mothers It is not known whether amlodipine is excreted in human milk. In the absence of this information, it is recommended that nursing be discontinued while amlodipine is administered.
WARNING AND CAUTIONS
5 WARNINGS AND PRECAUTIONS Symptomatic hypotension is possible, particularly in patients with severe aortic stenosis. However, acute hypotension is unlikely. (5.1) Worsening angina and acute myocardial infarction can develop after starting or increasing the dose of amlodipine, particularly in patients with severe obstructive coronary artery disease. (5.2) Titrate slowly in patients with severe hepatic impairment. (5.3) 5.1 Hypotension Symptomatic hypotension is possible, particularly in patients with severe aortic stenosis. Because of the gradual onset of action, acute hypotension is unlikely. 5.2 Increased Angina or Myocardial Infarction Worsening angina and acute myocardial infarction can develop after starting or increasing the dose of amlodipine, particularly in patients with severe obstructive coronary artery disease. 5.3 Patients with Hepatic Failure Because amlodipine besylate is extensively metabolized by the liver and the plasma elimination half-life (t1/2) is 56 hours in patients with impaired hepatic function, titrate slowly when administering amlodipine besylate to patients with severe hepatic impairment.
DOSAGE AND ADMINISTRATION
2 •Adult recommended starting dose: 5 mg once daily with maximum dose 10 mg once daily. (2.1) о Small, fragile, or elderly patients, or patients with hepatic insufficiency may be started on 2.5 mg once daily. (2.1) •Pediatric starting dose: 2.5 mg to 5 mg once daily. (2.2) Important Limitation: Doses in excess of 5 mg daily have not been studied in pediatric patients. (2.2) 2.1 Adults The usual initial antihypertensive oral dose of amlodipine besylate tablet is 5 mg once daily and the maximum dose is 10 mg once daily. Small, fragile, or elderly patients, or patients with hepatic insufficiency may be started on 2.5 mg once daily and this dose may be used when adding amlodipine besylate tablet USP to other antihypertensive therapy. Adjust dosage according to blood pressure goals. In general, wait 7 to 14 days between titration steps. Titrate more rapidly, however, if clinically warranted, provided the patient is assessed frequently. Angina The recommended dose for chronic stable or vasospastic angina is 5 to 10 mg, with the lower dose suggested in the elderly and in patients with hepatic insufficiency. Most patients will require 10 mg for adequate effect. Coronary artery disease The recommended dose range for patients with coronary artery disease is 5 to 10 mg once daily. In clinical studies, the majority of patients required 10 mg [see CLINICAL STUDIES (14.4)] . 2.2 Children The effective antihypertensive oral dose in pediatric patients ages 6 to 17 years is 2.5 mg to 5 mg once daily. Doses in excess of 5 mg daily have not been studied in pediatric patients [see CLINICAL PHARMACOLOGY (12.4), CLINICAL STUDIES (14.1)] .