Benazepril

Oral
Hypertension

CrCl (mL/min)	Dosage
<30	Initially, 5 mg once daily, may be titrated until blood pressure is controlled. Max: 40 mg daily.

May be taken with or without food.

History of angioedema with or without previous ACE inhibitor therapy. Pregnancy. Concomitant use with aliskiren in patients with diabetes and renal impairment (GFR <60 mL/min/1.73 m²); concurrent use with or within 36 hours of switching to or from a neprilysin inhibitor (e.g. sacubitril).

Patient with CHF, ischaemic heart disease, severe aortic stenosis, hypertrophic cardiomyopathy with left ventricular outflow tract obstruction, cerebrovascular disease, hyponatraemia, volume and/or salt depletion, unilateral or bilateral renal artery stenosis, diabetes mellitus, ascites, collagen vascular disease. Patient undergoing major surgery, dialysis, apheresis, or desensitisation treatment (e.g. hymenoptera venom). Black patient. Renal and hepatic impairment. Children and elderly. Lactation.

Significant: Symptomatic hypotension with or without syncope; reduced renal function (including acute renal failure), hyperkalaemia, non-productive cough.
Blood and lymphatic system disorders: Haemolytic anaemia, thrombocytopenia, eosinophilia.
Gastrointestinal disorders: Nausea, vomiting, constipation, gastritis, melaena.
General disorders and administration site conditions: Fatigue, asthenia.
Investigations: Increased uric acid, blood glucose, serum bilirubin, and liver enzymes; ECG changes.
Metabolism and nutrition disorders: Hyponatraemia, proteinuria.
Musculoskeletal and connective tissue disorders: Hypertonia, myalgia, arthralgia, arthritis.
Nervous system disorders: Dizziness, headache, somnolence, paraesthesia.
Psychiatric disorders: Insomnia, nervousness, anxiety.
Renal and urinary disorders: UTI, urinary frequency.
Reproductive system and breast disorders: Decreased libido, impotence.
Respiratory, thoracic and mediastinal disorders: Bronchitis, asthma, dyspnoea, sinusitis.
Skin and subcutaneous tissue disorders: Alopecia, Stevens-Johnson syndrome, pemphigus, photosensitivity, sweating.
Vascular disorders: Flushing.
Potentially Fatal: Angioedema (including laryngeal angioedema and tongue oedema); anaphylactic/anaphylactoid reactions; cholestatic jaundice that may progress to fulminant hepatic necrosis.

PO: D

Monitor blood pressure, renal function (e.g. BUN, serum creatinine), and serum K level (particularly in patients concomitantly taking K-sparing diuretics, K supplements and/or K-containing salts) periodically. Assess for signs of angioedema. Periodically monitor CBC with differential in patients with collagen vascular disease and/or renal impairment.

Symptoms: Hypotension which may be associated with electrolyte disturbances and renal failure. Management: Supportive treatment. If ingestion is recent, consider administration of activated charcoal; gastric decontamination (e.g. vomiting, gastric lavage) may be considered in the early period after ingestion. Monitor blood pressure and clinical symptoms. Ensure adequate hydration. Infuse 0.9% NaCl to treat marked hypotension and consider vasopressors (e.g. catecholamines) if necessary. Consider dialysis in patients with severe renal impairment.

Increased risk of hyperkalaemia with K-sparing diuretics (e.g. spironolactone, triamterene, amiloride), K supplements and/or K-containing salt substitutes. May enhance the hypotensive effect with diuretics. May increase the risk of hypoglycaemia with antidiabetic agents (e.g. insulins, oral hypoglycaemic agents). Concomitant use of NSAIDs may result in deterioration of renal function, including acute renal failure, and reduced antihypertensive effect of benazepril. May increase the risk of angioedema with mammalian target of rapamycin (mTOR) inhibitors (e.g. sirolimus, everolimus, temsirolimus). Increased serum concentration and toxicity of lithium. May cause nitritoid reactions (e.g. facial flushing, nausea, vomiting, hypotension) with Na aurothiomalate.
Potentially Fatal: Increased risks of hypotension, hyperkalaemia, and changes in renal function (including acute renal failure) with aliskiren. May increase the risk of angioedema with neprilysin inhibitors (e.g. sacubitril).

May result in false-negative aldosterone/renin ratio (ARR).

Description:
Mechanism of Action: Benazepril, a prodrug of benazeprilat, is an ACE inhibitor. It competitively inhibits the conversion of angiotensin I to angiotensin II (a potent vasoconstrictor) through the angiotensin I-converting enzyme (ACE) activity, thereby reducing the levels of angiotensin II which leads to an increase in plasma renin activity and decreased aldosterone secretion.
Onset: 1-2 hours (peak effect).
Duration: Approx 24 hours.
Pharmacokinetics:
Absorption: Rapidly absorbed. Time to peak plasma concentrations: Benazepril: 0.5-1 hour; benazeprilat: 1-2 hours (fasting state); 2-4 hours (nonfasting state).
Distribution: Crosses the placenta (benazepril); enters breast milk in small amounts (benazepril and benazeprilat). Volume of distribution: Approx 8.7 L. Plasma protein binding: Approx 97% (benazepril); approx 95% (benazeprilat).
Metabolism: Rapidly and extensively metabolised in the liver to benazeprilat (active metabolite) via enzymatic hydrolysis; both benazepril and benazeprilat undergo glucuronidation. Undergoes extensive first-pass metabolism.
Excretion: Mainly via urine (approx 37%; 20% as benazeprilat, 12% as other metabolites, trace amounts of benazepril); faeces (approx 11-12% as benazeprilat). Elimination half-life: Benazeprilat: 10-11 hours (effective); 22 hours (terminal).

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 5362124, Benazepril. https://pubchem.ncbi.nlm.nih.gov/compound/Benazepril. Accessed June 27, 2022.

Store between 15-30°C. Protect from moisture.

ACE Inhibitors/Direct Renin Inhibitors

C09AA07 - benazepril ; Belongs to the class of ACE inhibitors. Used in the treatment of cardiovascular disease.

Anon. Benazepril. AHFS Clinical Drug Information [online]. Bethesda, MD. American Society of Health-System Pharmacists, Inc. https://www.ahfscdi.com. Accessed 03/06/2022.

Anon. Benazepril. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 03/06/2022.

Benazepril Hydrochloride Tablet, Film Coated (Aurobindo Pharma Limited). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 03/06/2022.

Buckingham R (ed). Benazepril Hydrochloride. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 03/06/2022.