Benazepril

Benazepril: Uses, Dosage and Side Effects

Overview

• Angiotensin-converting enzyme (ACE) inhibitor.
• It inhibits the conversion of angiotensin I to angiotensin II and inhibits the breakdown of bradykinin.
• The overall effect is a reduction in preload and afterload via venodilation and arteriodilation, decreased salt and water retention via reduced aldosterone production and inhibition of the angiotensin-aldosterone-mediated cardiac and vascular remodelling.
• Efferent arteriolar dilation in the kidney can reduce intraglomerular pressure and therefore glomerular filtration. This may decrease proteinuria.

Uses of Benazepril

• Treatment of congestive heart failure in dogs and cats. Often used in conjunction with diuretics when heart failure is present as most effective when used in these cases.
• Can be used in combination with other drugs to treat heart failure (e.g. pimobendan, furosemide, spironolactone, digoxin).
• Management of proteinuria associated with chronic renal insufficiency, glomerular disorders and protein-losing nephropathies.
• May reduce blood pressure in hypertension, and may be more potent in dogs. Less potent in reducing blood pressure compared with amlodipine in cats but sometimes used together

Dose of Benazepril in Dogs and Cats

Dogs:

• Heart failure: 0.25–0.5 mg/kg p.o. q24h.
• Adjunctive treatment of hypertension/proteinuria: 0.25–0.5 mg/kg p.o. q12–24h.

Cats:

• Chronic renal insufficiency: 0.5–1.0 mg/kg p.o. q24h.
• Adjunctive therapy in heart failure: 0.25–0.5 mg/kg p.o. q24h.

Side Effects of Benazepril in Dogs and Cats

• Potential adverse effects include hypotension, hyperkalemia, and azotemia.
• Anorexia, vomiting, and diarrhea are rare.
• It is not recommended for breeding, or pregnant or lactating dogs and cats, as safety has not been established.
• The safety of benazepril has not been established in cats <2.5 kg.

Contraindications of Benazepril in Dogs and Cats

• Do not use in cases of cardiac output failure or hypotension.

Some Notes:

• Benazepril undergoes significant hepatic metabolism and may not need dose adjustment in renal failure.
• ACE inhibitors are more likely to cause or exacerbate prerenal azotaemia in hypotensive animals and those with poor renal perfusion (e.g. acute, oliguric renal failure).
• Use cautiously if hypotension, hyponatremia or outflow tract obstruction are present.
• Regular monitoring of blood pressure, serum creatinine, urea and electrolytes is strongly recommended with ACE inhibitor treatment.
• Concomitant usage with potassium-sparing diuretics (e.g. spironolactone) or potassium supplements could result in hyperkalemia. However, in practice, spironolactone and ACE inhibitors appear safe to use concurrently. There may be an increased risk of nephrotoxicity and decreased clinical efficacy when used with NSAIDs.
• There is a risk of hypotension with concomitant administration of diuretics, vasodilators (e.g. anaesthetic agents, antihypertensive agents) or negative inotropes (e.g. beta-blockers).