2.1 Recommended Dosage

ADULTS

The recommended initial dose for patients not receiving a diuretic is 10 mg once a day.  The usual maintenance dosage range is 20 to 40 mg per day administered as a single dose or in two equally divided doses.  A dose of 80 mg gives an increased response, but experience with this dose is limited.  The divided regimen was more effective in controlling trough (pre-dosing) blood pressure than the same dose given as a once-daily regimen.

Use with diuretics in adults

The recommended starting dose of benazepril hydrochloride in a patient on a diuretic is 5 mg once daily.  If blood pressure is not controlled with benazepril hydrochloride alone, a low dose of diuretic may be added.

PEDIATRIC PATIENTS 6 YEARS OF AGE AND OLDER

The recommended starting dose for pediatric patients is 0.2 mg/kg once per day. Titrate as needed to 0.6 mg/kg once per day.  Doses above 0.6 mg/kg (or in excess of 40 mg daily) have not been studied in pediatric patients.

Benazepril hydrochloride is not recommended in pediatric patients less than 6 years of age or in pediatric patients with GFR less than 30 mL/min/1.73m2 [see Use in Specific Populations (8.3)].

2.2 Dose Adjustment for Renal Impairment

For adults with a GFR <30 mL/min/1.73 m2 (serum creatinine >3 mg/dL), the recommended initial dose is 5 mg benazepril hydrochloride once daily.  Dosage may be titrated upward until blood pressure is controlled or to a maximum total daily dose of 40 mg.  Benazepril hydrochloride can also worsen renal function [see Warnings and Precautions (5.3)].

2.3 Preparation of Suspension (for 150 mL of a 2 mg/mL Suspension)

Add 75 mL of Ora-Plus®* oral suspending vehicle to an amber polyethylene terephthalate (PET) bottle containing fifteen benazepril hydrochloride 20 mg tablets, and shake for at least two minutes. Allow the suspension to stand for a minimum of 1 hour.  After the standing time, shake the suspension for a minimum of one additional minute.  Add 75 mL of Ora-Sweet®* oral syrup vehicle to the bottle and shake the suspension to disperse the ingredients.  The suspension should be refrigerated at 2º to 8°C (36º to 46°F) and can be stored for up to 30 days in the PET bottle with a child-resistant screw-cap closure.  Shake the suspension before each use. 

*Ora-Plus® and Ora-Sweet® are registered trademarks of Paddock Laboratories, Inc. Ora Plus® contains carrageenan, citric acid, methylparaben, microcrystalline cellulose, carboxymethylcellulose sodium, potassium sorbate, simethicone, sodium phosphate monobasic, xanthan gum, and water. Ora-Sweet® contains citric acid, berry citrus flavorant, glycerin, methylparaben, potassium sorbate, sodium phosphate monobasic, sorbitol, sucrose, and water.

5.1 Fetal Toxicity

Benazepril hydrochloride can cause fetal harm when administered to a pregnant woman.  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 benazepril hydrochloride as soon as possible [see Use in Specific Populations (8.1)].

5.2 Angioedema and Anaphylactoid Reactions

Angioedema

Head and Neck Angioedema

Angioedema of the face, extremities, lips, tongue, glottis, and/or larynx including some fatal reactions, have occured in patients treated with benazepril hydrochloride.  Patients with involvement of the tongue, glottis or larynx are likely to experience airway obstruction, especially those with a history of airway surgery.  Benazepril hydrochloride should be promptly discontinued and appropriate therapy and monitoring should be provided until complete and sustained resolution of signs and symptoms of angioedema has occurred.

Patients with a history of angioedema unrelated to ACE inhibitor therapy may be at increased risk of angioedema while receiving an ACE inhibitor [see Contraindications (4)]. ACE inhibitors have been associated with a higher rate of angioedema in Black than in non-Black patients.

Patients receiving co-administration of ACE inhibitor and mTOR (mammalian target of rapamycin) inhibitor (e.g., temsirolimus, sirolimus, everolimus) therapy or a neprilysin inhibitor may be at increased risk for angioedema [see Drug Interactions (7.7)].

Intestinal Angioedema

Intestinal angioedema has occurred 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.  In some cases, the angioedema was diagnosed by procedures including abdominal CT scan or ultrasound, or at surgery, and symptoms resolved after stopping the ACE inhibitor.

Anaphylactoid Reactions

Anaphylactoid Reactions During Desensitization

Two patients undergoing desensitizing treatment with hymenoptera venom while receiving ACE inhibitors sustained life-threatening anaphylactoid reactions.

Anaphylactoid Reactions During Dialysis

Sudden and potentially life threatening anaphylactoid reactions have occurred in some patients dialyzed with high-flux membranes and treated concomitantly with an ACE inhibitor.  In such patients, dialysis must be stopped immediately, and aggressive therapy for anaphylactoid reactions must be initiated.  Symptoms have not been relieved by antihistamines in these situations.  In these patients, consideration should be given to using a different type of dialysis membrane or a different class of antihypertensive agent. Anaphylactoid reactions have also been reported in patients undergoing low-density lipoprotein apheresis with dextran sulfate absorption.

5.3 Impaired Renal Function

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

5.4 Hypotension

Benazepril hydrochloride can cause symptomatic hypotension, sometimes complicated by oliguria, progressive azotemia, acute renal failure, or death.  Patients at risk of excessive hypotension include those with the following conditions or characteristics: heart failure with systolic blood pressure below 100 mm Hg, ischemic heart disease, cerebrovascular disease, hyponatremia, high dose diuretic therapy, renal dialysis, or severe volume and/or salt depletion of any etiology.

In such patients, follow closely for the first 2 weeks of treatment and whenever the dose of benazepril or diuretic is increased.  Avoid use of benazepril hydrochloride in patients who are hemodynamically unstable after acute MI.

Surgery/Anesthesia

In patients undergoing major surgery or during anesthesia with agents that produce hypotension, benazepril hydrochloride may block angiotensin II formation secondary to compensatory renin release.  If hypotension occurs, correct by volume expansion.

5.5 Hyperkalemia

Serum potassium should be monitored periodically in patients receiving benazepril hydrochloride.  Drugs that inhibit 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 [see Drug Interactions (7.1)].

5.6 Hepatic Failure

ACE inhibitors have been associated with a syndrome that starts with cholestatic jaundice and progresses to fulminant hepatic necrosis and (sometimes) death.  The mechanism of this syndrome is not understood.  Patients receiving ACE inhibitors who develop jaundice or marked elevations of hepatic enzymes should discontinue the ACE inhibitor and receive appropriate medical follow-up.

7.1 Diuretics

Hypotension

Patients on diuretics, especially those in whom diuretic therapy was recently instituted, may occasionally experience an excessive reduction of blood pressure after initiation of therapy with benazepril hydrochloride.  The possibility of hypotensive effects with benazepril hydrochloride can be minimized by either discontinuing or decreasing the dose of diuretic prior to initiation of treatment with benazepril hydrochloride [see Dosage and Administration (2.1)].

Hyperkalemia

Potassium-sparing diuretics (spironolactone, amiloride, triamterene, and others) can increase the risk of hyperkalemia. Therefore, if concomitant use of such agents is indicated, monitor the patient's serum potassium frequently. Benazepril hydrochloride attenuates potassium loss caused by thiazide-type diuretics.

7.2 Antidiabetics

Concomitant administration of benazepril hydrochloride and antidiabetic medicines (insulins, oral hypoglycemic agents) may increase the risk of hypoglycemia.

7.3 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.

7.4 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.  Most patients receiving the combination of two RAS inhibitors do not obtain any additional benefit compared to monotherapy.  In general, avoid combined use of RAS inhibitors.  Closely monitor blood pressure, renal function and electrolytes in patients on benazepril hydrochloride and other agents that affect the RAS.

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

7.5 Mammalian Target of Rapamycin (mTOR) Inhibitors

Patients receiving co-administration of ACE inhibitor and mTOR inhibitor (e.g., temsirolimus, sirolimus, everolimus) therapy may be at increased risk for angioedema. Monitor for signs of angioedema [see Warnings and Precautions (5.2)].

7.6 Lithium

Lithium toxicity has been reported in patients receiving lithium concomitantly with benazepril hydrochloride. Lithium toxicity was usually reversible upon discontinuation of lithium or benazepril hydrochloride. Monitor serum lithium levels during concurrent use.

7.7 Neprilysin Inhibitor

Patients taking concomitant neprilysin inhibitors may be at increased risk for angioedema [see Warnings and Precautions].

7.8 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.

8.1 Pregnancy

Risk Summary

Benazepril hydrochloride can cause fetal harm when administered to a pregnant woman.  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.  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.  When pregnancy is detected, discontinue benazepril hydrochloride as soon as possible.

The estimated background risk of major birth defects and miscarriage for the indicated population are unknown.  All pregnancies have a background risk of birth defect, loss, or other adverse outcomes.  In the general U.S. population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.

Clinical Considerations

Disease-associated maternal and/or embryo/fetal risk

Hypertension in pregnancy increases the maternal risk for pre-eclampsia, gestational diabetes, premature delivery, and delivery complications (e.g., need for cesarean section, and post-partum hemorrhage). Hypertension increases the fetal risk for intrauterine growth restriction and intrauterine death. Pregnant women with hypertension should be carefully monitored and managed accordingly.

Fetal/Neonatal Adverse Reactions

Oligohydramnios in pregnant women who use drugs affecting the renin-angiotensin system in the second and third trimesters of pregnancy can result in the following: reduced fetal renal function leading to anuria and renal failure, fetal lung hypoplasia and skeletal deformations, including skull hypoplasia, hypotension, and death. 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. 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 benazepril hydrochloride for hypotension, oliguria, and hyperkalemia.  If oliguria or hypotension occur in neonates with a history of in utero exposure to benazepril hydrochloride, support blood pressure and renal perfusion.  Exchange transfusions or dialysis may be required as a means of reversing hypotension and substituting for disordered renal function.

8.2 Lactation

Minimal amounts of unchanged benazepril and of benazeprilat are excreted into the breast milk of lactating women treated with benazepril.  A newborn child ingesting entirely breast milk would receive less than 0.1% of the mg/kg maternal dose of benazepril and benazeprilat.

8.3 Pediatric Use

The antihypertensive effects of benazepril hydrochloride have been evaluated in a double-blind study in pediatric patients 7 to 16 years of age [see Clinical Pharmacology (12.3)].  The pharmacokinetics of benazepril hydrochloride have been evaluated in pediatric patients 6 to 16 years of age [see Clinical Pharmacology (12.3)].

Infants below the age of 1 year should not be given benazepril hydrochloride because of the risk of effects on kidney development.

Safety and effectiveness of benazepril hydrochloride have not been established in pediatric patients less than 6 years of age or in children with glomerular filtration rate <30 mL/min/1.73m2 [see Dosage and Administration (2.1) and Clinical Pharmacology (12.3)].

8.4 Geriatric Use

Of the total number of patients who received benazepril in U.S. clinical studies of benazepril hydrochloride, 18% were 65 or older while 2% were 75 or older.  No overall differences in effectiveness or safety were observed between these patients and younger patients, and other reported 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.

Benazepril and benazeprilat are substantially excreted by the kidney. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function [see Dosage and Administration (2.2)].

8.5 Race

ACE inhibitors, including benazepril hydrochloride, as monotherapy, have an effect on blood pressure that is less in Black patients than in non-Blacks.

8.6 Renal Impairment

Dose adjustment of benazepril hydrochloride is required in patients undergoing hemodialysis or whose creatinine clearance is ≤30 mL/min. No dose adjustment of benazepril hydrochloride is required in patients with creatinine clearance > 30 mL/min [see Dosage and Administration (2.2) and Clinical Pharmacology (12.3)].

12.1 Mechanism of Action

Benazepril and benazeprilat inhibit angiotensin-converting enzyme (ACE) in human subjects and animals.  Benazeprilat has much greater ACE inhibitory activity than does benazepril.

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.

Removal of angiotensin II negative feedback on renin secretion leads to increased plasma renin activity.  In animal studies, benazepril had no inhibitory effect on the vasopressor response to angiotensin II and did not interfere with the hemodynamic effects of the autonomic neurotransmitters acetylcholine, epinephrine, and norepinephrine.

ACE is identical to kininase, an enzyme that degrades bradykinin.  Whether increased levels of bradykinin, a potent vasodepressor peptide, play a role in the therapeutic effects of benazepril hydrochloride remains to be elucidated.  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.

12.2 Pharmacodynamics

Single and multiple doses of 10 mg or more of benazepril hydrochloride cause inhibition of plasma ACE activity by at least 80% to 90% for at least 24 hours after dosing.  Pressor responses to exogenous angiotensin I were inhibited by 60% to 90% (up to 4 hours post-dose) at the 10 mg dose.

Drug Interactions

Benazepril hydrochloride has been used concomitantly with beta-adrenergic-blocking agents, calcium-channel-blocking agents, diuretics, digoxin, and hydralazine, without evidence of clinically important adverse interactions.  Benazepril, like other ACE inhibitors, has had less than additive effects with beta-adrenergic blockers, presumably because both drugs lower blood pressure by inhibiting parts of the renin-angiotensin system.

12.3 Pharmacokinetics

The pharmacokinetics of benazepril are approximately dose-proportional within the dosage range of 10 to 80 mg.

Following oral administration of benazepril hydrochloride, peak plasma concentrations of benazepril, and its active metabolite benazeprilat are reached within 0.5 to 1.0 hour and 1 to 2 hours, respectively.  While the bioavailability of benazepril is not affected by food, time to peak plasma concentrations of benazeprilat is delayed to 2 to 4 hours.

The serum protein binding of benazepril is about 96.7% and that of benazeprilat about 95.3%, as measured by equilibrium dialysis; on the basis of in vitro studies, the degree of protein binding should be unaffected by age, hepatic dysfunction, or concentration (over the concentration range of 0.24 to 23.6 µmol/L).

Benazepril is almost completely metabolized to benazeprilat by cleavage of the ester group (primarily in liver).  Both benazepril and benazeprilat undergo glucuronidation.

Benazepril and benazeprilat are cleared predominantly by renal excretion.  About 37% of an orally administered dose was recovered in urine as benazeprilat (20%), benazeprilat glucuronide (8%), benazepril glucuronide (4%) and as trace amounts of benazepril. Nonrenal (i.e., biliary) excretion accounts for approximately 11% to 12% of benazeprilat excretion.  The effective half-life of benazeprilat following once daily repeat oral administration of benazepril hydrochloride is 10 to 11 hours.  Thus, steady-state concentrations of benazeprilat should be reached after 2 or 3 doses of benazepril hydrochloride given once daily.

Accumulation ratio based on AUC of benazeprilat was 1.19 following once daily administration.

Specific Populations

Renal impairment

The pharmacokinetics of systemic exposure to 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 initial (alpha phase) half-life increase, and time to steady-state may be delayed [see Dosage and Administration (2)].

When dialysis was started 2 hours after ingestion of 10 mg of benazepril, approximately 6% of benazeprilat was removed in 4 hours of dialysis.  The parent compound, benazepril, was not detected in the dialysate.

Hepatic impairment

In patients with hepatic insufficiency (due to cirrhosis), the pharmacokinetics of benazeprilat are essentially unaltered.

Drug Interactions

The pharmacokinetics of benazepril are not affected by the following drugs: hydrochlorothiazide, furosemide, chlorthalidone, digoxin, propranolol, atenolol, nifedipine, amlodipine, naproxen, acetylsalicylic acid, or cimetidine.  Likewise the administration of benazepril does not substantially affect the pharmacokinetics of these medications (cimetidine kinetics were not studied).

Pediatrics

The pharmacokinetics of benazapril, evaluated in pediatric patients with hypertension following oral administration of a single dose is presented in table below.

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

No evidence of carcinogenicity was found when benazepril was administered to rats and mice for up to two years at doses of up to 150 mg/kg/day.  When compared on the basis of body weights, this dose is 110 times the maximum recommended human dose.  When compared on the basis of body surface areas, this dose is 18 and 9 times (rats and mice, respectively) the maximum recommended human dose (calculations assume a patient weight of 60 kg).  No mutagenic activity was detected in the Ames test in bacteria (with or without metabolic activation), in an in vitro test for forward mutations in cultured mammalian cells, or in a nucleus anomaly test.  In doses of 50 to 500 mg/kg/day (6 to 60 times the maximum recommended human dose based on mg/m2 comparison and 37 to 375 times the maximum recommended human dose based on a mg/kg comparison), benazepril hydrochloride had no adverse effect on the reproductive performance of male and female rats.