benazepril hydrochloride

Action

Inhibits conversion of angiotensin I to angiotensin II, a vasoconstrictor that stimulates adrenal glands and promotes aldosterone secretion, thereby reducing sodium and water reabsorption and ultimately decreasing blood pressure. Decreased angiotensin also causes increased potassium level and fluid loss.

Availability

Tablets: 5 mg, 10 mg, 20 mg, 40 mg

Indications and dosages

➣ Hypertension

Adults: Initially, 5 to 10 mg/day P.O. as a single dose. Increase gradually to a maintenance dosage of 20 to 40 mg/day as a single dose or in two divided doses. (Start with 5 mg/day in patients receiving diuretics.)

Dosage adjustment

• Renal impairment

Off-label uses

• Myocardial infarction

• Nephropathy

Contraindications

• Hypersensitivity to drug or to other ACE inhibitors

• Angioedema with or without previous ACE inhibitor treatment

Precautions

Use cautiously in:

• renal or hepatic impairment, hypovolemia, hyponatremia, aortic stenosis, hypertrophic cardiomyopathy, cerebrovascular or cardiac insufficiency

• patients receiving concurrent diuretics

• black patients

• elderly patients

• pregnant patients (use not recommended, particularly in second and third trimesters)

• breastfeeding patients

• children.

Administration

See Use extreme caution if patient has family history of angioedema.

• When giving concurrently with diuretics, know that drug may cause excessive hypotension. If possible, stop diuretic therapy 2 to 3 days before starting benazepril.

• Give with or without food.

• Know that drug may be used alone or in conjunction with other antihypertensives.

Adverse reactions

CNS: dizziness, drowsiness, fatigue, syncope, light-headedness, headache, insomnia

CV: angina pectoris, hypotension, tachycardia

EENT: sinusitis

GI: diarrhea, nausea, anorexia

GU: proteinuria, erectile dysfunction, decreased libido, renal failure

Hematologic: agranulocytosis

Metabolic: hyperkalemia

Respiratory: cough, dyspnea, bronchitis, asthma, eosinophilic pneumonitis

Skin: rash, angioedema

Other: fever, altered taste

Interactions

Drug-drug. Allopurinol: increased risk of hypersensitivity reaction

Antacids: decreased benazepril absorption

Antihypertensives, diuretics, general anesthetics, nitrates, phenothiazines: excessive hypotension

Cyclosporine, indomethacin, potassium-sparing diuretics, potassium supplements: hyperkalemia

Lithium: increased lithium blood level, greater risk of lithium toxicity

Nonsteroidal anti-inflammatory drugs: blunting of antihypertensive response

Drug-diagnostic tests. Alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, bilirubin, blood urea nitrogen, creatinine, potassium: increased levels

Antinuclear antibodies: positive result

Sodium: decreased level

Drug-food. Salt substitutes containing potassium: hyperkalemia

Drug-herbs. Capsaicin: cough

Drug-behaviors. Acute alcohol ingestion: increased hypotension

Patient monitoring

See Monitor for signs and symptoms of angioedema, including laryngeal edema and shock.

• Measure blood pressure regularly.

• Monitor CBC, electrolyte levels, kidney and liver function test results, and urinary protein level.

Patient teaching

See Tell patient to immediately report change in urination pattern, difficulty breathing, or swelling of throat or lips.

• Instruct patient to record blood pressure at various intervals daily.

• Tell patient to report dizziness, fainting, or light-headedness during initial therapy.

• Advise patient to increase fluid intake during exercise and in hot weather.

• Caution patient to avoid salt substitutes, which may cause hyperkalemia.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, foods, herbs, and behaviors mentioned above.