Benazepril Hydrochloride


Indications

Benazepril hydrochloride 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 the class to which this drug principally belongs.

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.

It may be used alone or in combination with thiazide diuretics.

contraindications

Benazepril hydrochloride tablets are contraindicated in patients:

who are hypersensitive to benazapril or to any other ACE inhibitor
with a history of angioedema with or without previous ACE inhibitor treatment

Do not coadminister aliskiren with benazepril hydrochloride tablets in patients with diabetes [see Drug Interactions (7.4)].

adverse reactions

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice.

Benazepril hydrochloride has been evaluated for safety in over 6000 patients with hypertension; over 700 of these patients were treated for at least one year. The overall incidence of reported adverse events was similar in benazepril hydrochloride and placebo patients.

The reported side effects were generally mild and transient, and there was no relation between side effects and age, duration of therapy, or total dosage within the range of 2 to 80 mg.

Discontinuation of therapy because of a side effect was required in approximately 5% of U.S. patients treated with benazepril hydrochloride and in 3% of patients treated with placebo. The most common reasons for discontinuation were headache (0.6%) and cough (0.5%)

Adverse reactions seen in at least 1% greater frequency in patients treated with benazepril hydrochloride than placebo were headache (6% vs 4%), dizziness (4% vs 2%), somnolence (2% vs 0%) and postural dizziness (2% vs 0%).

Adverse reactions reported in controlled clinical trials (less than 1% more on benazepril than on placebo), and rarer events seen in post-marketing experience, include the following (in some, a causal relationship to drug use is uncertain):

Dermatologic: Stevens-Johnson syndrome, pemphigus, apparent hypersensitivity reactions (manifested by dermatitis, pruritus, or rash), photosensitivity, and flushing.

Gastrointestinal: Nausea, pancreatitis, constipation, gastritis, vomiting, and melena.

Hematologic: Thrombocytopenia and hemolytic anemia.

Neurologic/Psychiatric: Anxiety, decreased libido, hypertonia, insomnia, nervousness, and paresthesia

Other: Fatigue, asthma, bronchitis, dyspnea, sinusitis, urinary tract infection, frequent urination, infection, arthritis, impotence, alopecia, arthralgia, myalgia, asthenia, sweating.

Laboratory Abnormalities:

Elevations of uric acid, blood glucose, serum bilirubin, and liver enzymes [see Warnings and Precautions (6.5)] have been reported, as have incidents of hyponatremia, electrocardiographic changes, eosinophilia, and proteinuria

warnings and precautions

5.1 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 benazepril hydrochloride as soon as possible [see Use in Specific Populations (8.1)].

5.2 Angioedema and Anaphylactoid Reactions

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 coadministration of ACE inhibitor and mTOR (mammalian target of rapamycin) inhibitor (e.g., temsirolimus, sirolimus, everolimus) therapy may be at increased risk for 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.

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

Sudden and potentially life threatening anaphylactoid reactions have occured 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 sytem. 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 mmHg, 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.

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.

overdosage

Single oral doses of 3 g/kg benazepril were associated with significant lethality in mice. Rats, however, tolerated single oral doses of up to 6 g/kg. Reduced activity was seen at 1 g/kg in mice and at 5 g/kg in rats. Human overdoses of benazepril have not been reported, but the most common manifestation of human benazepril overdosage is likely to be hypotension, for which the usual treatment would be intravenous infusion of normal saline solution. Hypotension can be associated with electrolyte disturbances and renal failure.

Benazepril is only slightly dialyzable, but consider dialysis to support patients with severely impaired renal function [see Warnings and Precautions (5.3)].

If ingestion is recent, consider activated charcoal. Consider gastric decontamination (e.g., vomiting, gastric lavage) in the early period after ingestion.

Monitor for blood pressure and clinical symptoms. Supportive management should be employed to ensure adequate hydration and to maintain systemic blood pressure.

In the case of marked hypotension, infuse physiological saline solution; as needed, consider vasopressors (e.g., catecholamines i.v.).

description

Benazepril hydrochloride, USP is a white to off-white crystalline powder, soluble (> 100 mg/mL) in water, in ethanol, and in methanol. Its chemical name is 3-[[1-(ethoxy-carbonyl)-3-phenyl-(1S)-propyl]amino]-2,3,4,5-tetrahydro-2-oxo-1H-1-(3S)-benzazepine-1-acetic acid monohydrochloride; its structural formula is

C24H28N2O5•HCl M.W. 460.96

Benazeprilat, the active metabolite of benazepril, is a non-sulfhydryl angiotensin-converting enzyme inhibitor.

Benazepril hydrochloride, USP is supplied as tablets containing 5 mg, 10 mg, 20 mg, and 40 mg of benazepril hydrochloride, USP for oral administration. The inactive ingredients are: colloidal silicon dioxide, corn starch, crospovidone, hypromellose, iron oxide yellow, lactose monohydrate, magnesium stearate, microcrystalline cellulose, polyethylene glycol, povidone, pregelatinized starch, titanium dioxide, and triacetin. Additionally, the 5 mg strength contains talc, the 20 mg strength contains iron oxide black and iron oxide red, and the 40 mg strength contains iron oxide red.

Benazepril Hydrochloride Package Photos

About the Author

Truman Lewis
Truman has been a bureau chief and correspondent in D.C., Los Angeles, Phoenix and elsewhere, reporting for radio, television, print and news services, for more than 30 years. Most recently, he has reported extensively on health and consumer issues for ConsumerAffairs.com and FairfaxNews.com.