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Amlodipine Besylate and Benazepril Hydrochloride Capsules

TABLE OF CONTENTS

1. DESCRIPTION 7. WARNINGS AND PRECAUTIONS
2. INDICATIONS AND USAGE 8. ADVERSE REACTIONS
3. DOSAGE AND ADMINISTRATION 9. OVERDOSAGE
4. CONTRAINDICATIONS 10. DRUG INTERACTIONS
5. MECHANISM OF ACTION 11. PHARMACOKINETICS
6. USE IN SPECIFIC POPULATIONS 12. HOW SUPPLIED/STORAGE AND HANDLING

 

BLACK BOX WARNING


WARNING: FETAL TOXICITY

When pregnancy is detected, discontinue amlodipine/benazepril as soon as possible.

Drugs that act directly on the renin-angiotensin system can cause injury and death to the developing fetus. See Warnings: Fetal Toxicity.


 

1. DESCRIPTION

Amlodipine and benazepril capsules is a combination of amlodipine besylate and benazepril hydrochloride. Amlodipine besylate is the besylate salt of amlodipine, a dihydropyridine calcium channel blocker. Benazeprilat, the active metabolite of benazepril, is a nonsulfhydryl angiotensin converting enzyme (ACE) inhibitor. Benazepril is converted to benazeprilat by hepatic cleavage of the ester group.

Benazepril hydrochloride has empirical formula of C24H28N2O5•HCl, and its molecular weight is 460.96, its structural formula is:

Amlodipine besylate has empirical formula of C20H25ClN2O5•C6H6O3S, and its molecular weight is 567.1, its structural formula is:

The inactive ingredients of the capsules are calcium phosphate, cellulose compounds, colloidal silicon dioxide, crospovidone, gelatin, hydrogenated castor oil (not present in 5/40 mg or 10/40 mg strengths), iron oxides, lactose, magnesium stearate, polysorbate 80, silicon dioxide, sodium lauryl sulfate, sodium starch (potato) glycolate, starch (corn), talc, and titanium dioxide.

2. INDICATIONS AND USAGE

2.1 Hypertension

Amlodipine and benazepril is indicated for the treatment of hypertension in patients not adequately controlled on monotherapy with either agent.

3. DOSAGE AND ADMINISTRATION

3.1 General considerations

The recommended initial dose of amlodipine/benazepril is one capsule of amlodipine 2.5 mg/benazepril 10 mg orally once daily.

It is usually appropriate to begin therapy with amlodipine/benazepril only after a patient has either (a) failed to achieve the desired antihypertensive effect with amlodipine or benazepril monotherapy, or (b) demonstrated inability to achieve adequate antihypertensive effect with amlodipine therapy without developing edema.

The antihypertensive effect of amlodipine/benazepril is largely attained within 2 weeks. If blood pressure remains uncontrolled, the dose may be titrated up to amlodipine 10 mg/benazepril 40 mg once daily. The dosing should be individualized and adjusted according to the patient’s clinical response.

Amlodipine is an effective treatment of hypertension in once-daily doses of 2.5-10 mg while benazepril is effective in doses of 10-80 mg. In clinical trials of amlodipine/benazepril combination therapy using amlodipine doses of 2.5-10 mg and benazepril doses of 10-40 mg, the antihypertensive effects increased with increasing dose of amlodipine in all patient groups, and the effects increased with increasing dose of benazepril in nonblack groups.

3.2 Dosage adjustment in renal impairment

Renal Impairment: Amlodipine/benazepril is not recommended in patients with creatinine clearance ≤ 30 mL/min. No dose adjustment of amlodipine/benazepril is required in patients creatinine clearance > 30 mL/min (serum creatinine roughly ≤3 mg/dL or 265 μmol/L). [see Warnings and Precautions, Use in Specific Populations].

3.3 Replacement Therapy

Amlodipine/benazepril may be substituted for the titrated components.

4. CONTRAINDICATIONS

• Do not co-administer aliskiren with angiotensin receptor blockers, ACE inhibitors, including amlodipine/benazepril in patients with diabetes.

• Amlodipine/benazepril is contraindicated in patients with a history of angioedema, with or without previous ACE inhibitor treatment, or patients who are hypersensitive to benazepril, to any other ACE inhibitor, to amlodipine, or to any of the excipients of amlodipine/benazepril.

5. MECHANISM OF ACTION

Benazepril and benazeprilat inhibit angiotensin-converting enzyme (ACE) in human subjects and in animals. ACE is a peptidyl dipeptidase that catalyzes the conversion of angiotensin I to the vasoconstrictor substance angiotensin II. Angiotensin II also stimulates aldosterone secretion by the adrenal cortex.

Inhibition of ACE results in decreased plasma angiotensin II, which leads to decreased vasopressor activity and to decreased aldosterone secretion. The latter decrease may result in a small increase of serum potassium. Hypertensive patients treated with benazepril and amlodipine for up to 56 weeks had elevations of serum potassium up to 0.2 mEq/L.

While the mechanism through which benazepril lowers blood pressure is believed to be primarily suppression of the renin-angiotensin-aldosterone system, benazepril has an antihypertensive effect even in patients with low-renin hypertension.

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. 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.

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.

6. USE IN SPECIFIC POPULATIONS

6.1 Usage in Pregnancy

Pregnancy Category D

Use of drugs that act on the renin-angiotensin system during the second and third trimesters of pregnancy reduces fetal renal function and increases fetal and neonatal morbidity and death. Resulting oligohydramnios can be associated with fetal lung hypoplasia and skeletal deformations. Potential neonatal adverse effects include skull hypoplasia, anuria, hypotension, renal failure, and death. When pregnancy is detected, discontinue amlodipine/benazepril as soon as possible. These adverse outcomes are usually associated with use of these drugs in the second and third trimester of pregnancy. Most epidemiologic studies examining fetal abnormalities after exposure to antihypertensive use in the first trimester have not distinguished drugs affecting the renin-angiotensin system from other antihypertensive agents. Appropriate management of maternal hypertension during pregnancy is important to optimize outcomes for both mother and fetus.

In the unusual case that there is no appropriate alternative to therapy with drugs affecting the renin-angiotensin system for a particular patient, apprise the mother of the potential risk to the fetus. Perform serial ultrasound examinations to assess the intra-amniotic environment. If oligohydramnios is observed, discontinue amlodipine/benazepril, unless it is considered lifesaving for the mother. Fetal testing may be appropriate, based on the week of pregnancy. Patients and physicians should be aware, however, that oligohydramnios may not appear until after the fetus has sustained irreversible injury. Closely observe infants with histories of in utero exposure to amlodipine/benazepril for hypotension, oliguria, and hyperkalemia [see Use in Specific Populations].

6.2 Labor and Delivery

The effect of amlodipine/benazepril on labor and delivery has not been studied.

6.3 Nursing Mothers

Minimal amounts of unchanged benazepril and of benazeprilat are excreted into the breast milk of lactating women treated with benazepril, so that a newborn child ingesting nothing but breast milk would receive less than 0.1% of the maternal doses of benazepril and benazeprilat.

It is not known whether amlodipine is excreted in human milk. Nursing or drug should be discontinued.

6.4 Pediatric Use

Neonates with a history of in utero exposure to amlodipine/benazepril:

If oliguria or hypotension occurs, direct attention toward support of blood pressure and renal perfusion. Exchange transfusions or dialysis may be required as a means of reversing hypotension and/or substituting for disordered renal function. Benazepril, which crosses the placenta, can theoretically be removed from the neonatal circulation by these means; there are occasional reports of benefit from these maneuvers, but experience is limited.

6.5 Geriatric Use

In geriatrics, exposure to amlodipine is increased, thus consider lower initial doses of amlodipine/benazepril.

Of the total number of patients who received amlodipine/benazepril in U.S. clinical studies of amlodipine/benazepril, over 19% were 65 or older while about 2% were 75 or older. Overall differences in effectiveness or safety were not observed between these patients and younger patients. Clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

6.6 Hepatic Impairment

Exposure to amlodipine is increased in patients with hepatic insufficiency, thus consider using lower doses of amlodipine/benazepril.

6.7 Renal Impairment

In patients with severe renal impairment systemic exposure to benazepril is increased. The recommended dose of benazepril in this subgroup is 5 mg which is not an available strength with amlodipine/benazepril. Amlodipine/benazepril is not recommended in patients with severe renal impairment. No dose adjustment of amlodipine/benazepril is needed in patients with mild or moderate impairment of renal function [see Dosing and Administration, Warnings and Precaution].

7. WARNINGS AND PRECAUTIONS

7.1 Anaphylactoid and Possibly Related Reactions

Presumably because angiotensin-converting enzyme inhibitors affect the metabolism of eicosanoids and polypeptides, including endogenous bradykinin, patients receiving ACE inhibitors (including amlodipine and benazepril capsules) may be subject to a variety of adverse reactions, some of them serious. These reactions usually occur after one of the first few doses of the ACE inhibitor, but they sometimes do not appear until after months of therapy.

Head and Neck Angioedema: Angioedema of the face, extremities, lips, tongue, glottis, and larynx has been reported in patients treated with ACE inhibitors. In U.S. clinical trials, symptoms consistent with angioedema were seen in none of the subjects who received placebo and in about 0.5% of the subjects who received benazepril. Angioedema associated with laryngeal edema can be fatal. If laryngeal stridor or angioedema of the face, tongue, or glottis occurs, treatment with amlodipine and benazepril capsules should be discontinued and appropriate therapy instituted immediately. When involvement of the tongue, glottis, or larynx appears likely to cause airway obstruction, appropriate therapy, e.g., subcutaneous epinephrine injection 1:1000 (0.3-0.5 mL), should be promptly administered (see ADVERSE REACTIONS).

Intestinal Angioedema: Intestinal angioedema has been reported in patients treated with ACE inhibitors. These patients presented with abdominal pain (with or without nausea or vomiting); in some cases there was no prior history of facial angioedema and C-1 esterase levels were normal. The angioedema was diagnosed by procedures including abdominal CT scan or ultrasound, or at surgery, and symptoms resolved after stopping the ACE inhibitor. Intestinal angioedema should be included in the differential diagnosis of patients on ACE inhibitors presenting with abdominal pain.

Anaphylactoid Reactions During Desensitization: Two patients undergoing desensitizing treatment with hymenoptera venom while receiving ACE inhibitors sustained life-threatening anaphylactoid reactions. In the same patients, these reactions were avoided when ACE inhibitors were temporarily withheld, but they reappeared upon inadvertent rechallenge.

Anaphylactoid Reactions During Membrane Exposure: Anaphylactoid reactions have been reported in patients dialyzed with high-flux membranes and treated concomitantly with an ACE inhibitor. Anaphylactoid reactions have also been reported in patients undergoing lowdensity lipoprotein apheresis with dextran sulfate absorption.

Increased Angina and/or Myocardial Infarction: Rarely, patients, particularly those with severe obstructive coronary artery disease, have developed documented increased frequency, duration, and/or severity of angina or acute myocardial infarction on starting calcium channel blocker therapy or at the time of dosage increase. The mechanism of this effect has not been elucidated.

7.2 Increased Angina and/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.

7.3 Patients with Aortic and Mitral Valve Stenosis, Obstructive Hypertrophic Cardiomyopathy

As with all other vasodilators, special caution is required when using amlodipine in patients suffering from aortic or mitral stenosis, or obstructive hypertrophic cardiomyopathy.

7.4 Hypotension

Amlodipine/benazepril can cause symptomatic hypotension. Symptomatic hypotension is most likely to occur in patients who have been volume or salt depleted as a result of diuretic therapy, dietary salt restriction, dialysis, diarrhea, or vomiting. Volume and/or salt depletion should be corrected before starting therapy with benazepril. If hypotension occurs, the patient should be placed in the supine position and if necessary given physiological saline i.v. Treatment with benazepril can be continued once blood pressure and volume have returned to normal.

In patients with congestive heart failure, with or without associated renal insufficiency, ACE inhibitor therapy may cause excessive hypotension, which may be associated with oliguria, azotemia, and (rarely) with acute renal failure and death. In such patients, amlodipine and benazepril capsules therapy should be started under close medical supervision; they should be followed closely for the first 2 weeks of treatment and whenever the dose of the benazepril component is increased or a diuretic is added or its dose increased.

Symptomatic hypotension is also possible in patients with severe aortic stenosis.

7.5 Fetal Toxicity

Pregnancy Category D

Use of drugs that act on the renin-angiotensin system during the second and third trimesters of pregnancy reduces fetal renal function and increases fetal and neonatal morbidity and death. Resulting oligohydramnios can be associated with fetal lung hypoplasia and skeletal deformations. Potential neonatal adverse effects include skull hypoplasia, anuria, hypotension, renal failure, and death. When pregnancy is detected, discontinue amlodipine/benazepril as soon as possible [see Use in Specific Populations].

7.6 Hepatitis and Hepatic Failure

There have been rare reports of predominantly cholestatic hepatitis and isolated cases of acute liver failure, some of them fatal, in patients on ACE inhibitors. The mechanism is not understood. Patients receiving ACE inhibitors who develop jaundice or marked elevation of hepatic enzymes should discontinue the ACE inhibitor and be kept under medical surveillance.

7.7 Impaired Renal Function

Monitor renal function periodically in patients treated with amlodipine/benazepril. Changes in renal function, including acute renal failure, can be caused by drugs that affect the renin-angiotensin system. Patients whose renal function may depend in part on the activity of the renin-angiotensin system (e.g., patients with renal artery stenosis, severe heart failure, post-myocardial infarction or volume depletion) or who are on NSAIDS or angiotensin receptor blockers may be at particular risk of developing acute renal failure on amlodipine/benazepril. Consider withholding or discontinuing therapy in patients who develop a clinically significant decrease in renal function on amlodipine/benazepril.

7.8 Hyperkalemia

Monitor serum potassium periodically in patients receiving amlodipine/benazepril. Drugs that affect the renin-angiotensin system can cause hyperkalemia. Risk factors for the development of hyperkalemia include renal insufficiency, diabetes mellitus, and the concomitant use of potassium-sparing diuretics, potassium supplements, and/or potassium-containing salt substitutes. . In U.S. placebo-controlled trials of amlodipine/benazepril, hyperkalemia (serum potassium at least 0.5 mEq/L greater than the upper limit of normal) not present at baseline occurred in approximately 1.5% of hypertensive patients receiving amlodipine/benazepril. Increases in serum potassium were generally reversible.

7.9 Cough

Presumably due to the inhibition of the degradation of endogenous bradykinin, persistent nonproductive cough has been reported with all ACE inhibitors, generally resolving after discontinuation of therapy. Consider ACE inhibitor-induced cough in the differential diagnosis of cough.

7.10 Surgery/Anesthesia

In patients undergoing surgery or during anesthesia with agents that produce hypotension, benazepril will block the angiotensin II formation that could otherwise occur secondary to compensatory renin release. Hypotension that occurs as a result of this mechanism can be corrected by volume expansion.

8. ADVERSE REACTIONS

8.1 Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The adverse reaction information from clinical trials does, however, provide a basis for identifying the adverse events that appear to be related to drug use and for approximating rates.

Amlodipine and benazepril has been evaluated for safety in over 2,991 patients with hypertension; over 500 of these patients were treated for at least 6 months, and over 400 were treated for more than 1 year.

In a pooled analysis of 5 placebo-controlled trials involving amlodipine and benazepril doses up to 5/20, the reported side effects were generally mild and transient, and there was no relationship between side effects and age, sex, race, or duration of therapy. Discontinuation of therapy due to side effects was required in approximately 4% of patients treated with amlodipine and benazepril and in 3% of patients treated with placebo.

The most common reasons for discontinuation of therapy with amlodipine and benazepril in these studies were cough and edema (including angioedema).

The peripheral edema associated with amlodipine use is dose-dependent. When benazepril is added to a regimen of amlodipine, the incidence of edema is substantially reduced.

The addition of benazepril to a regimen of amlodipine should not be expected to provide additional antihypertensive effect in African-Americans. However, all patient groups benefit from the reduction in amlodipine-induced edema.

The side effects considered possibly or probably related to study drug that occurred in these trials in more than 1% of patients treated with amlodipine and benazepril are shown in the table below. Cough was the only adverse event with at least possible relationship to treatment that was more common on amlodipine and benazepril (3.3%) than on placebo (0.2%).

Table 1: Percent Incidence in U.S. Placebo-Controlled Trials

* Edema refers to all edema, such as dependent edema, angioedema, facial edema.

__________________________________________________________________

The incidence of edema was greater in patients treated with amlodipine monotherapy (5.1%) than in patients treated with amlodipine and benazepril (2.1%) or placebo (2.2%).

8.2 Post-marketing Experience

Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

In postmarketing experience with benazepril, there have been rare reports of Stevens-Johnson syndrome, pancreatitis, hemolytic anemia, pemphigus, thrombocytopenia, paresthesia, dysgeusia, orthostatic symptoms and hypotension, angina pectoris and arrhythmia, pruritus, photosensitivity reaction, arthralgia, arthritis, myalgia, BUN increase, serum creatinine increased, renal impairment, impaired vision, agranulocytosis, neutropenia.

Rare reports in association with use of amlodipine: gingival hyperplasia, tachycardia, jaundice, and hepatic enzyme elevations (mostly consistent with cholestasis severe enough to require hospitalization) ,leucocytopenia, allergic reaction, hyperglycemia, dysgeusia, hypoestheia, paresthesia, syncope, peripheral neuropathy, hypertonia, visual impairment, diplopia, hypotension, vasculitis, rhinitis, gastritis, hyperhidrosis, pruritis, skin discoloration, urticaria, erythema multiform, muscle spasms, arthralgia, micturition disorder, nocturia, erectile dysfunction, malaise, weight decrease or gain.

Other potentially important adverse experiences attributed to other ACE inhibitors and calcium channel blockers include: eosinophilic pneumonitis (ACE inhibitors) and gynecomastia (CCBs). Other infrequently reported events included chest pain, ventricular extrasystole, gout, neuritis, tinnitus, alopecia, upper respiratory tract infection, palpitations and somnolence.

9. OVERDOSAGE

Only a few cases of human overdose with amlodipine have been reported. One patient was asymptomatic after a 250-mg ingestion; another, who combined 70 mg of amlodipine with an unknown large quantity of a benzodiazepine, developed refractory shock and died.

Human overdoses with any combination of amlodipine and benazepril have not been reported. In scattered reports of human overdoses with benazepril and other ACE inhibitors, there are no reports of death.

Treatment:

Patients should be admitted to hospital and, generally, should be managed in an intensive care setting, with continuous monitoring of cardiac function, blood gases, and blood biochemistry. Emergency supportive measures such as artificial ventilation or cardiac pacing should be instituted if appropriate.

In the event of a potentially life-threatening oral overdose, use induction of vomiting or gastric lavage and/or activated charcoal to remove the drug from the gastrointestinal tract (only if presented within 1 hour after ingestion of amlodipine/benazepril).

Other clinical manifestations of overdose should be managed symptomatically based on modern methods of intensive care.

To obtain up-to-date information about the treatment of overdose, a good resource is your certified Regional Poison-Control Center. Telephone numbers of certified poison control centers are listed in the Physicians’ Desk Reference (PDR). In managing overdose, consider the possibilities of multiple-drug overdoses, drug-drug interactions, and unusual drug kinetics in your patient.

The most likely effect of overdose with amlodipine and benazepril capsules is vasodilation, with consequent hypotension and tachycardia. Simple repletion of central fluid volume (Trendelenburg positioning, infusion of crystalloids) may be sufficient therapy, but pressor agents (norepinephrine or high-dose dopamine) may be required. Overdoses of other dihydropyridine calcium channel blockers are reported to have been treated with calcium chloride and glucagon, but evidence of a dose-response relation has not been seen, and these interventions must be regarded as unproven. With abrupt return of peripheral vascular tone, overdoses of other dihydropyridine calcium channel blockers have sometimes progressed to pulmonary edema, and patients must be monitored for this complication.

Analyses of bodily fluids for concentrations of amlodipine, benazepril, or their metabolites are not widely available. Such analyses are, in any event, not known to be of value in therapy or prognosis.

No data are available to suggest physiologic maneuvers (e.g., maneuvers to change the pH of the urine) that might accelerate elimination of amlodipine, benazepril, or their metabolites. Benazeprilat is only slightly dialyzable; attempted clearance of amlodipine by hemodialysis or hemo-perfusion has not been reported, but amlodipine’s high protein binding makes it unlikely that these interventions will be of value.

Angiotensin II could presumably serve as a specific antagonist-antidote to benazepril, but angiotensin II is essentially unavailable outside of scattered research laboratories.

10. DRUG INTERACTIONS

Amlodipine

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.

CYP3A4 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 CYP3A4 inhibitors to determine the need for dose adjustment.

CYP3A4 Inducers: No information is available on the quantitative effects of CYP3A4 inducers on amlodipine. Blood pressure should be monitored when amlodipine is co-administered with CYP3A4 inducers.

Benazepril

Potassium Supplements and Potassium-Sparing Diuretics: Benazepril can attenuate potassium loss caused by thiazide diuretics. Potassium-sparing diuretics (spironolactone, amiloride, triamterene, and others) or potassium supplements can increase the risk of hyperkalemia. If concomitant use of such agents is indicated, the patient’s serum potassium should be monitored frequently.

Lithium: Increased serum lithium levels and symptoms of lithium toxicity have been reported in patients receiving ACE inhibitors during therapy with lithium. When coadministering amlodipine/benazepril and lithium, frequent monitoring of serum lithium levels is recommended.

Gold: Nitritoid reactions (symptoms include facial flushing, nausea, vomiting and hypotension) have been reported rarely in patients on therapy with injectable gold (sodium aurothiomalate) and concomitant ACE inhibitor therapy.

Non-Steroidal Anti-Inflammatory Agents including Selective Cyclooxygenase-2 Inhibitors (COX-2 Inhibitors): In patients who are elderly, volume-depleted (including those on diuretic therapy), or with compromised renal function, co-administration of NSAIDs, including selective COX-2 inhibitors, with ACE inhibitors, including benazepril, may result in deterioration of renal function, including possible acute renal failure. These effects are usually reversible. Monitor renal function periodically in patients receiving benazepril and NSAID therapy.

The antihypertensive effect of ACE inhibitors, including benazepril, may be attenuated by NSAIDs.

Antidiabetic agents: In rare cases, diabetic patients receiving an ACE inhibitor (including benazepril) concomitantly with insulin or oral antidiabetics may develop hypoglycemia. Such patients should therefore be advised about the possibility of hypoglycemic reactions, and should be monitored accordingly.

Dual Blockade of the Renin-Angiotensin System (RAS): Dual blockade of the RAS with angiotensin receptor blockers, ACE inhibitors, or aliskiren is associated with increased risks of hypotension, hyperkalemia, and changes in renal function (including acute renal failure) compared to monotherapy. Closely monitor blood pressure, renal function and electrolytes in patients on amlodipine/benazepril and other agents that block the RAS.

Do not co-administer aliskiren with amlodipine/benazepril in patients with diabetes. Avoid use of aliskiren with amlodipine/benazepril in patients with renal impairment (GFR <60 ml/min).

11. PHARMACOKINETICS

The rate and extent of absorption of benazepril and amlodipine from amlodipine/benazepril are same as when administered as individual tablets. Absorption from the individual tablets is not influenced by the presence of food in the gastrointestinal tract; food effects on absorption from amlodipine/benazepril have not been studied.

Absorption

Following oral administration of amlodipine/benazepril, peak plasma concentrations of amlodipine are reached in 6–12 hours. Absolute bioavailability has been calculated as between 64% and 90%. Following oral administration of amlodipine/benazepril, the peak plasma concentrations of benazepril are reached in 0.5-2 hours. The cleavage of the ester group (primarily in the liver) converts benazepril to its active metabolite, benazeprilat, which reaches peak plasma concentrations in 1.5-4 hours. The extent of absorption of benazepril is at least 37%. Amlodipine and benazepril exhibit dose proportional pharmacokinetics between the therapeutic dose range of 2.5 and 10 mg and 10 and 20 mg, respectively.

Distribution

The apparent volume of distribution of amlodipine is about 21 L/kg. In vitro studies indicate that approximately 93% of circulating amlodipine is bound to plasma proteins in hypertensive patients. The apparent volume of distribution of benazeprilat is about 0.7 L/kg. Approximately 93% of circulating amlodipine is bound to plasma proteins, and the bound fraction of benazeprilat is slightly higher. On the basis of in vitro studies, benazeprilat’s degree of protein binding should be unaffected by age, by hepatic dysfunction, or—over the therapeutic concentration range—by concentration.

Metabolism

Amlodipine is extensively (approximately 90%) metabolized in the liver to inactive metabolites. Benazepril is extensively metabolised to form benazeprilat as the main metabolite, which occur by enzymatic hydrolysis, mainly in the liver. Two minor metabolites are the acyl glucuronide conjugates of benazepril and benazeprilat.

Elimination

Amlodipine elimination from plasma is biphasic with a terminal elimination half-life of approximately 30 to 50 hours. Steady-state plasma levels are reached after once-daily dosing for 7 - 8 days. 10% of unchanged drug and 60% of amlodipine metabolites are excreted in urine. Effective elimination half-life of amlodipine is 2 days. Benazepril is eliminated mainly by metabolic clearance. Benazeprilat is eliminated via the kidneys and the bile; renal excretion is the main route in patients with normal renal function. In the urine, benazepril accounts for less than 1 % and benazeprilat for about 20 % of an oral dose. Elimination of benazeprilat is biphasic with an initial half-life of about 3 hours and a terminal half-life of about 22 hours. Benazeprilat’s effective elimination half-life is 10-11 h, while that of amlodipine is about 2 days, so steady-state levels of the two components are achieved after about a week of once-daily dosing.

Special populations

Geriatric patients: No specific clinical studies were performed to understand the impact of age on the pharmacokinetics of amlodipine and benazepril as fixed dose combination. As individual component amlodipine is extensively metabolized in the liver. In the elderly, clearance of amlodipine is decreased with resulting increases in peak plasma levels, elimination half-life and area-under-the-plasma-concentration curve [see Use in Specific Populations].

Hepatic impairment: Patients with hepatic insufficiency have decreased clearance of amlodipine with a resulting increase in AUC of approximately 40–60%. Pharmacokinetics of benazepril is not significantly influenced by hepatic impairment [see Use in Specific Populations].

Renal impairment: The disposition of benazepril and benazeprilat in patients with mild-to-moderate renal insufficiency (creatinine clearance > 30 mL/min) is similar to that in patients with normal renal function. In patients with creatinine clearance ≤ 30 mL/min, peak benazeprilat levels and the effective half-life increase, resulting in higher systemic exposures. Pharmacokinetics of amlodipine is not significantly influenced by renal impairment [see Dosage and Administration, Use in Specific Populations and Warnings and Precautions].

12. HOW SUPPLIED/STORAGE AND HANDLING

1) How Available:

a) Brand name: LOTREL, by NOVARTIS.

b) Generic drugs: Amlodipine besylate and hydrochloride, by various manufacturers.

2) How Supplied:

Amlodipine besylate and benazepril hydrochloride combination capsules (by Watson) are available as capsules containing amlodipine besylate equivalent to 2.5 mg, 5 mg or 10 mg of amlodipine, with 10 mg or 20 mg of benazepril hydrochloride providing for the following available combinations: 2.5/10 mg, 5/10 mg, 5/20 mg and 10 mg/20 mg.

Amlodipine besylate and benazepril hydrochloride combination capsules 2.5 mg/10 mg are supplied as “a hard gelatin, white opaque capsule with ‘>’ over ‘AB’ on the cap and ‘1’ printed in black on the body.”

Bottles of 100 0591-3757-01

Amlodipine besylate and benazepril hydrochloride combination capsules 5 mg/10 mg are supplied as “a hard gelatin, white opaque capsule with ‘>’ over ‘AB’ on the cap and ‘2’ printed in black on the body.”

Bottles of 100 0591-3758-01

Bottles of 500 0591-3758-05

Amlodipine besylate and benazepril hydrochloride combination capsules 5 mg/20 mg are supplied as “a hard gelatin, white opaque capsule with ‘>’ over ‘AB’ on the cap and ‘3’ printed in black on the body.”

Bottles of 100 0591-3759-01

Bottles of 500 0591-3759-05

Amlodipine besylate and benazepril hydrochloride combination capsules 10 mg/20 mg are supplied as “a hard gelatin, white opaque capsule with ‘>’ over ‘AB’ on the cap and ‘4’ printed in black on the body.”

Bottles of 100 0591-3760-01

Bottles of 500 0591-3760-05

3) Storage: Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F). Protect from moisture. Dispense in tight container.

Rx only

Rev 10/12