Canada-Approved Medicine

This monograph describes a medication approved for use in Canada by the Therapeutic Products Directorate, a division of Health Canada’s Health Products and Food Branch. The medication is not approved by the United States Food and Drug Administration; however, a similar formulation carrying a different generic or brand name might be available in the US.


Trade Name(s)

  • Inhibace Canadian Trade name

Ther. Class.


Pharm. Class.

ace inhibitors


  • Alone or with other agents in the management of hypertension.
  • HF.


ACE inhibitors block the conversion of angiotensin I to the vasoconstrictor angiotensin II. ACE inhibitors also prevent the degradation of bradykinin and other vasodilatory prostaglandins. ACE inhibitors also ↑ plasma renin levels and ↓ aldosterone levels. Net result is systemic vasodilation.

Therapeutic Effect(s):

  • Lowering of BP in hypertensive patients.
  • Improved symptoms in patients with HF.


Absorption: Well absorbed following oral administration, rapidly converted to active metabolite, cilazaprilat (57% bioavailability for cilazaprilat).

Distribution: Enters breast milk.

Metabolism and Excretion: Cilazaprilat is eliminated unchanged by the kidneys (91%).

Half-life: Early elimination phase: 0.9 hr;  terminal elimination phase (enzyme-bound cilazaprilat) : 36–49 hr.

TIME/ACTION PROFILE (effects on hemodynamics)

PO (hypertension)within 1 hr3–7 hr12–24 hr
PO (heart failure)1–2 hr2–4 hr24 hr


Contraindicated in:

  • Hypersensitivity;
  • History of angioedema with previous use of ACE inhibitors;
  • Concurrent use with aliskiren in patients with diabetes or moderate to severe renal impairment (CCr <60 mL/min);
  • OB:  Can cause injury or death of fetus: if pregnancy occurs, discontinue immediately;
  • Lactation: Discontinue drug or use formula.

Use Cautiously in:

  • Renal impairment, hepatic impairment, hypovolemia, hyponatremia, concurrent diuretic therapy;
  • Genetic implication Black patients with hypertension (monotherapy less effective, may require additional therapy; ↑ risk of angioedema);
  • Rep:  Women of reproductive potential;
  • Surgery/anesthesia (hypotension may be exaggerated);
  • Geri:  Initial dose ↓ recommended for most agents due to age-related ↓ in renal function;
  • Pedi:  Safety and effectiveness not established.

Exercise Extreme Caution in:

Family history of angioedema.

Adverse Reactions/Side Effects

CNS: dizziness, drowsiness, fatigue, headache, insomnia, vertigo, weakness

Resp: cough, dyspnea

CV: hypotension, chest pain, edema, tachycardia

Endo: hyperuricemia

GI: taste disturbances, abdominal pain, anorexia, constipation, diarrhea, nausea, vomiting

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

Derm: flushing, pruritis, rashes

F and E: hyperkalemia


MS: back pain, muscle cramps, myalgia

Misc: ANGIOEDEMA, fever

* CAPITALS indicate life-threatening.
Underline indicate most frequent.



  • Excessive hypotension may occur with concurrent use of  diuretics  or other  antihypertensives  or  alcohol.
  • ↑ risk of hyperkalemia with concurrent use of  potassium supplements,  potassium-sparing diuretics, or  potassium-containing salt substitutes.
  • ↑ risk of hyperkalemia, renal impairment, hypotension, and syncope with concurrent use of  angiotensin II receptor antagonists  or  aliskiren ; avoid concurrent use with aliskiren in patients with diabetes or CCr <60 mL/min.
  •  NSAIDs  and selective  COX-2 inhibitors  may blunt the antihypertensive effect and ↑ the risk of renal dysfunction.
  • ↑ levels and may ↑ risk of  lithium  toxicity.



PO (Adults ≤65 yr): As monotherapy: 2.5 mg once daily initially, may be increased every 2 wk by 2.5 mg/day; usual dose 2.5–5 mg once daily, not to exceed 10 mg/day. Twice daily administration may be necessary in some patients;  With diuretics: 0.5 mg once daily initially, titrate carefully.

PO (Adults >65 yr): As monotherapy: 1.25 mg once daily initially, titrate carefully.

Renal Impairment 
PO (Adults): CCr >40 mL/min: 1 mg once daily initially, titrate carefully, not to exceed 5 mg once daily;  CCr 10–40 mL/min: 0.5 mg once daily initially, titrate carefully, not to exceed 2.5 mg once daily;  CCr <10 mL/min: not recommended.

Hepatic Impairment 
PO (Adults): 0.5 mg once daily or less.

Heart Failure

PO (Adults): After considering concurrent diuretic therapy/salt/volume depletion,  Initial dose: 0.5 mg/day with careful monitoring, after 5 days dose may be ↑ to 1 mg/day, dose may then be carefully titrated as needed/tolerated up to 2.5 mg/day; rarely patients may require 5 mg/day.

Renal Impairment 
PO (Adults): CCr 10–40 mL/min: 0.25–0.5 mg once daily;  CCr <10 mL/min: not recommended.


Tablets: 1 mg, 2.5 mg, 5 mg

In Combination with: hydrochlorothiazide 12.5 mg (Inhibace Plus)


  • Assess patient for signs of angioedema; dyspnea and facial swelling.
  • Hypertension: Monitor BP and pulse frequently during initial dose adjustment and periodically during therapy. Notify health care professional of significant changes.
  • Heart Failure: Monitor daily weight and assess frequently for fluid overload (dyspnea, rales/crackles, weight gain, jugular venous distention).

Lab Test Considerations:

Monitor BUN, creatinine, and serum electrolyte levels periodically during therapy.

  • Monitor CBC periodically. May cause agranulocytosis.
  • May cause ↑ AST, ALT, alkaline phosphatase, serum bilirubin, uric acid, and glucose.


  • PO Tablets may be taken before or after meals.

Patient/Family Teaching

  • Instruct patient to take cilazapril as directed. Take missed dose as soon as remembered. If not until the following day, skip missed dose. Do not double doses.
  • Caution patient to change positions slowly to minimize hypotension. Use of alcohol, standing for long periods, exercising, and hot weather may ↑ orthostatic hypotension.
  • May cause dizziness. Caution patient to avoid driving and other activities requiring alertness until response to medication is known.
  • Instruct patient on proper technique for monitoring blood pressure. Advise patient to check BP and weight weekly and record and report results to health care professional.
  • Provide patient with additional interventions for hypertension control (weight reduction, low sodium diet, cessation of smoking, exercise regimen, stress management, and moderation of alcohol consumption). Medication controls but does not cure hypertension.
  • Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and consult health care professional before taking any new medications, especially cough, cold, or allergy remedies.
  • Rep:  Advise females of reproductive potential to use contraception and to notify health care professional if planning or suspecting pregnancy. Discontinue medication immediately if pregnancy is confirmed.

Evaluation/Desired Outcomes

  • Decrease in blood pressure.
  • Decrease in signs and symptoms of heart failure.