Benazepril
Benazepril HCl
Also known as: Fortekor · Lotensin · Benace · Boncordin · Briem · Cibacene · Labopal · Lotrel · Tensanil · Zinadril · Cardalis · Nelio · Benefortin · Benazecare · CGS-14824A · benazepril hydrochloride · Benazeprilum
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Audited v13 dosing evidence
Structured calculator evidenceAdjunctive treatment of hypertrophic heart failure (extralabel)
- q12-24h
NA
Governing clinical context (2)
- ■ This medicine may be given with or without food. It is usually well tolerated but vomiting and diarrhea can occur. Give with food if vomiting or lack of appetite becomes a problem.
- Benazepril tablets (and combination products) should be stored at temperatures less than 30°C (86°F) and protected from moisture.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Benazepril is an Angiotensin-Converting Enzyme (ACE) inhibitor widely used in veterinary medicine for the management of heart failure, systemic hypertension, chronic renal failure, and protein-losing glomerulonephropathies in dogs and cats.
Clinical Pearls:
- Unlike enalapril, which is almost exclusively cleared by the kidneys, benazepril's active metabolite (benazeprilat) is cleared via both hepatic (55%) and renal (45%) routes in dogs. This dual-excretion pathway makes it a preferred ACE inhibitor in patients with concurrent renal impairment.
- It is particularly beneficial in reducing intraglomerular hypertension, thereby decreasing proteinuria in chronic kidney disease.
- Because it lacks a sulfhydryl group (unlike captopril), it has a lower tendency to cause immune-mediated adverse reactions.
Mechanism of action
Benazepril is a prodrug that is hydrolyzed in the liver to its active metabolite, benazeprilat. It competitively inhibits Angiotensin-Converting Enzyme (ACE).
- Pathway: Angiotensin I → (blocked by ACE) → Angiotensin II
- Hemodynamic Effects: By preventing the formation of Angiotensin II (a potent vasoconstrictor), benazepril promotes vasodilation, reducing both preload and afterload in heart failure patients.
- Renal Effects: It dilates the efferent arterioles of the glomerulus more than the afferent arterioles, reducing intraglomerular capillary pressure and subsequently decreasing proteinuria.
- Endocrine Effects: Decreased Angiotensin II leads to reduced secretion of aldosterone from the adrenal cortex, minimizing sodium and water retention.
Safety & warnings
Contraindications
- Known hypersensitivity to ACE inhibitors
Adverse effects
- Anorexia
- Vomiting
- Diarrhea
- Hypotension
- Renal dysfunction (worsening azotemia)
- Hyperkalemia
Precautions
Important Warnings:
- Use with caution in patients with hyponatremia or sodium depletion, coronary or cerebrovascular insufficiency, preexisting hematologic abnormalities, or collagen vascular diseases (e.g., SLE).
- Patients with severe congestive heart failure (CHF) should be monitored very closely upon initiation of therapy due to the risk of profound hypotension.
- ACE inhibitors can potentially worsen preexisting azotemia. It is recommended to use a lower starting dose and closely monitor BUN and creatinine.
- Pregnancy: Mildly fetotoxic at high dosages. Use during pregnancy only when potential benefits outweigh the risks to the offspring (FDA Category C in first trimester, Category D in second/third trimesters).
Drug interactions
May potentially negate the decrease in systemic vascular resistance induced by ACE inhibitors (though low-dose aspirin may not significantly affect hemodynamics).
Possible increased risk for hypoglycemia; enhanced monitoring recommended.
Potential for increased hypotensive effects. Reducing furosemide doses by 25-50% is often recommended when initiating ACE inhibitors for heart failure.
Increased risk of hyperkalemia; enhanced monitoring of serum potassium is required.
Possible increased serum lithium levels; increased monitoring required.
Increased risk for hyperkalemia.
Potential for hyperkalemia due to additive potassium-sparing effects, though concurrent use is generally safe in practice.
Increased risk of nephrotoxicity and decreased clinical efficacy of benazepril.
Increased risk of hypotension and prerenal azotemia.
Additive hypotensive effects.
Increased risk of hypotension due to negative inotropic effects.
Monitoring
- Clinical signs of Congestive Heart Failure (CHF)
- Serum electrolytes (especially potassium)
- Renal panel (Creatinine, BUN)
- Urine protein (UPC ratio)
- Blood pressure (especially if treating hypertension or if signs of hypotension arise)
Pharmacokinetics
Half-life
Absorption
Rapidly absorbed after oral dosing in healthy dogs. In humans, food apparently does not affect the extent of absorption.
Distribution
Crosses the placenta and is distributed into milk in very small amounts. Highly bound to serum proteins (~95% in humans).
Metabolism
Hydrolyzed in the liver to the active metabolite, benazeprilat.
Elimination
In dogs, benazeprilat is cleared via both renal (45%) and hepatic (55%) routes. Mild to moderate renal dysfunction does not significantly alter elimination as biliary clearance compensates.
Overdose
In overdose situations, the primary concern is hypotension.
- Treatment: Supportive treatment with volume expansion using normal saline is recommended to correct blood pressure.
- Monitoring: Because of the drug's long duration of action, prolonged monitoring and treatment may be required.
- Decontamination: Recent massive overdoses should be managed using standard gut-emptying protocols (emesis, activated charcoal) as appropriate.
Available products
Formulations
- Oral tablets
Veterinary
- Benazepril Tablets: 2.5 mg, 5 mg, & 20 mg (Fortekor® - UK/POM-V)
Human-labeled
- Benazepril HCl Oral Tablets: 5 mg, 10 mg, 20 mg, & 40 mg (Lotensin®, generic)
- Fixed dose combination with amlodipine (Lotrel®)
- Fixed dose combination with hydrochlorothiazide (Lotensin HCT®)
Regulatory status
POM-V classification.
POM-V classification.
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store tablets at temperatures less than 86°F (30°C) and protect from moisture. Dispense in tight containers.
Client information
- Do Not Abruptly Stop: Do not abruptly stop or reduce therapy without your veterinarian's approval.
- Monitor for Side Effects: Contact your veterinarian immediately if vomiting or diarrhea persists or is severe, or if your animal's condition deteriorates (e.g., lethargy, weakness, fainting).
- Administration: Can be given with or without food. Ensure your pet always has access to fresh drinking water.
- Follow-up: Regular veterinary visits are crucial to monitor your pet's blood pressure and kidney function while on this medication.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.