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.
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.).
Lotensin is contraindicated in patients:
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.
Lotensin 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 Lotensin 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 Lotensin 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 Lotensin 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 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 AbnormalitiesElevations of uric acid, blood glucose, serum bilirubin, and liver enzymes have been reported, as have incidents of hyponatremia, electrocardiographic changes, eosinophilia, and proteinuria
Lotensin is 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.
Single and multiple doses of 10 mg or more of Lotensin cause inhibition of plasma ACE activity by at least 80%-90% for at least 24 hours after dosing. Pressor responses to exogenous angiotensin I were inhibited by 60%-90% (up to 4 hours post-dose) at the 10-mg dose.
Drug InteractionsLotensin 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 betaadrenergic blockers, presumably because both drugs lower blood pressure by inhibiting parts of the renin-angiotensin system
The pharmacokinetics of benazepril are approximately dose-proportional within the dosage range of 10-80 mg.
Following oral administration of Lotensin, peak plasma concentrations of benazepril, and its active metabolite benazeprilat are reached within 0.5-1.0 hours and 1-2 hours, respectively. While the bioavailability of benazepril is not affected by food, time to peak plasma concentrations of benazeprilat is delayed to 2 – 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- 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%-12% of benazeprilat excretion. The effective half-life of benazeprilat following once daily repeat oral administration of benazepril hydrochloride is 10-11 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.
Included as part of the "PRECAUTIONS" Section
PRECAUTIONS Fetal Toxicity Pregnancy Category DUse 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 Lotensin as soon as possible.
Angioedema And Anaphylactoid Reactions AngioedemaHead and Neck Angioedema
Angioedema of the face, extremities, lips, tongue, glottis, and/or larynx including some fatal reactions, have occured in patients treated with Lotensin. Patients with involvement of the tongue, glottis or larynx are likely to experience airway obstruction, especially those with a history of airway surgery. Lotensin 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. 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
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 ReactionsAnaphylactoid 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.
Impaired Renal FunctionMonitor renal function periodically in patients treated with Lotensin. 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 Lotensin. Consider withholding or discontinuing therapy in patients who develop a clinically significant decrease in renal function on Lotensin.
HypotensionLotensin 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 Lotensin in patients who are hemodynamically unstable after acute MI.
Surgery/AnesthesiaIn patients undergoing major surgery or during anesthesia with agents that produce hypotension, Lotensin may block angiotensin II formation secondary to compensatory renin release. If hypotension occurs, correct by volume expansion.
HyperkalemiaSerum potassium should be monitored periodically in patients receiving Lotensin. 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.
Hepatic FailureACE 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.
Nonclinical Toxicology Carciniogenesis, Mutagenesis, Impairment Of FertilityNo 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 50-500 mg/kg/day (6-60 times the maximum recommended human dose based on mg/m2 comparison and 37-375 times the maximum recommended human dose based on a mg/kg comparison), Lotensin had no adverse effect on the reproductive performance of male and female rats.
Use In Specific Populations Pregnancy Pregnancy Category DUse 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 Lotensin 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 reninangiotensin 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 Lotensin, 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 Lotensin for hypotension, oliguria, and hyperkalemia.
Nursing MothersMinimal 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.
Pediatric UseThe antihypertensive effects of Lotensin have been evaluated in a double-blind study in pediatric patients 7 to 16 years of age. The pharmacokinetics of Lotensin have been evaluated in pediatric patients 6 to 16 years of age.
Infants below the age of 1 year should not be given Lotensin because of the risk of effects on kidney development.
Safety and effectiveness of Lotensin 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.
Neonates With A History Of In Utero Exposure To Lotensin: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 with another ACE inhibitor, but experience is limited.
Geriatric UseOf the total number of patients who received benazepril in U.S. clinical studies of Lotensin, 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.
RaceACE inhibitors, including Lotensin, as monotherapy, have an effect on blood pressure that is less in Black patients than in non-Blacks.
Renal ImpairmentDose adjustment of Lotensin is required in patients undergoing hemodialysis or whose creatinine clearance is ≤30 mL/min. No dose adjustment of Lotensin is required in patients with creatinine clearance >30 mL/min.
The recommended initial dose for patients not receiving a diuretic is 10 mg once a day. The usual maintenance dosage range is 20 mg 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 AdultsThe recommended starting dose of Lotensin in a patient on a diuretic is 5 mg once daily. If blood pressure is not controlled with Lotensin alone, a low dose of diuretic may be added.
Pediatric Patients 6 Years Of Age And OlderThe 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.
Lotensin 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.
Dose Adjustment For Renal ImpairmentFor adults with a GFR <30 mL/min/1.73 m2 (serum creatinine >3 mg/dL), the recommended initial dose is 5 mg Lotensin once daily. Dosage may be titrated upward until blood pressure is controlled or to a maximum total daily dose of 40 mg. Lotensin can also worsen renal function.
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 Lotensin 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 2 8°C (36-46°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.
