quinapril hydrochloride

Action

Inhibits conversion of angiotensin I to angiotensin II, a potent vasoconstrictor; decreases cardiac output. Increases plasma renin levels and reduces aldosterone levels, causing systemic vasodilation.

Availability

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

Indications and dosages

➣ Hypertension

Adults: Initially, 10 to 20 mg P.O. daily for patients not receiving diuretics, with subsequent dosages adjusted at 2-week intervals according to blood pressure response at peak (2 to 6 hours) and trough (predose) blood levels; for maintenance, 20 to 80 mg/day as a single dose or in two divided doses. In patients receiving diuretics, discontinue diuretic 2 to 3 days before starting quinapril; if blood pressure isn't controlled, resume diuretic. If diuretic can't be discontinued, start therapy with 5 mg/day quinapril.

➣ Adjunct in heart failure

Adults: Initially, 5 mg P.O. b.i.d., titrated weekly until effective dosage is determined. For maintenance, 20 to 40 mg/day in two evenly divided doses.

Dosage adjustment

• Renal impairment

• Elderly patients

Off-label uses

• Aortic insufficiency

• Atherosclerosis

• Postoperative hypertension

• Myocardial infarction

• Diabetic or nondiabetic neuropathy

Contraindications

• Hypersensitivity to drug or other ACE inhibitors

• Angioedema caused by other ACE inhibitors

Precautions

Use cautiously in:

• autoimmune diseases, aortic stenosis, renal artery stenosis, hypertrophic cardiomyopathy, cerebrovascular or cardiac insufficiency, collagen vascular disease, hepatic or renal impairment, hypovolemia, hyponatremia, hypotension, neutropenia, chronic cough, proteinuria, febrile illness

• family history of angioedema

• risk factors for development of hyperkalemia, including renal insufficiency, diabetes mellitus, concurrent use of potassium-sparing diuretics, potassium supplements, or potassium-containing salt substitutes

• concurrent use of nonsteroidal antiinflammatory drugs (NSAIDs) in patients who are elderly, volume-depleted (including those on diuretics), or with compromised renal function

• concurrent immunosuppressant, lithium, or diuretic therapy

• black patients

• elderly patients

• pregnant or breastfeeding patients

• children (safety not established).

Administration

• Administer with or without food, but not with high-fat meal.

• Know that if quinapril alone doesn't adequately control blood pressure, a diuretic may be added.

Adverse reactions

CNS: dizziness, drowsiness, fatigue, headache, insomnia, depression, vertigo, paresthesia, asthenia, malaise, nervousness, syncope

CV: hypotension, angina pectoris, palpitations, chest pain, tachycardia, arrhythmias

EENT: amblyopia, sinusitis, pharyngitis

GI: nausea, vomiting, diarrhea, constipation, abdominal pain, anorexia, dry mouth

GU: erectile dysfunction

Metabolic: hyperkalemia

Musculoskeletal: back pain

Respiratory: cough, dyspnea

Skin: rash, pruritus, alopecia, flushing, diaphoresis, photosensitivity

Other: taste disturbances, fever, viral infections, hypersensitivity reactions including anaphylaxis

Interactions

Drug-drug.

Diuretics, other antihypertensives: increased hypotension

Gold (sodium aurothiomalate): increased risk of rare nitritoid reactions (including facial flushing, nausea, vomiting, and hypotension)

Lithium: increased serum lithium level and lithium toxicity

NSAIDs: may result in deterioration of renal function, including acute renal failure and attenuated ACE inhibitor antihypertensive effect

Potassium-sparing diuretics, potassium supplements: increased risk of hyperkalemia

Tetracyclines: decreased tetracycline absorption

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

Drug-food. High-fat foods: decreased rate and extent of drug absorption

Salt substitutes containing potassium: increased risk of hyperkalemia

Patient monitoring

• Monitor vital signs and cardiovascular status. Be sure to ask patient if he's experiencing angina.

• Assess CBC and liver function tests.

• Monitor potassium level. Watch for evidence of hyperkalemia.

Watch closely for signs and symptoms of angioedema, especially in black patients after first dose.

• Assess for dry, nonproductive cough and signs and symptoms of infection.

• Monitor renal function periodically in patients receiving concurrent NSAID therapy.

Patient teaching

• Tell patient he may take with or with­out food, but not with high-fat meal.

Advise patient to immediately report facial or tongue swelling or difficulty breathing.

• Instruct patient to monitor and record his blood pressure.

• Tell patient to promptly report dry, nonproductive cough and signs and symptoms of infection.

• Instruct patient to move slowly when sitting up or standing, to avoid dizziness or light-headedness from sudden blood pressure decrease.

• Tell patient that excessive fluid loss (as from sweating, vomiting, or diarrhea) and inadequate fluid intake increase the risk of light-headedness (especially in hot weather).

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.

• Advise patient to avoid salt substitutes containing potassium.

• Tell female patient to notify prescriber of possible pregnancy. Caution her not to breastfeed.

• 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.