Prinivil, Zestril
Classifications: cardiovascular agent; angiotensin-converting enzyme (ace) inhibitor; antihypertensive agent
Prototype: Enalapril
Pregnancy Category: D


2.5 mg, 5 mg, 10 mg, 20 mg, 30 mg, 40 mg tablets


Lowers BP by specific inhibition of the angiotensin-converting enzyme (ACE). This interrupts conversion sequences initiated by renin that form angiotensin II, a potent vasoconstrictor. ACE inhibition alters hemodynamics without compensatory reflex tachycardia or changes in cardiac output (except in patients with CHF).

Therapeutic Effects

Improved cardiac output and exercise tolerance due to inhibition of ACE also decreases circulating aldosterone, which is normally released in response to angiotensin II stimulation. Reduced aldosterone is associated with a potassium-sparing effect. Also decreases peripheral resistance (afterload) and pulmonary vascular resistance.


Hypertension, alone or concomitantly with other classes of antihypertensive agents; CHF; to improve MI survival.


Patients with a history of angioedema related to treatment with an ACE inhibitor, ACE inhibitor hypersensitivity; pregnancy (category D), children <6 y; lactation.

Cautious Use

Impaired kidney function, hyperkalemia, patients on diuretic therapy; aortic stenosis, cardiomyopathy; cerebrovascular disease; collagen vascular disease; coronary artery disease, dialysis; older adults; heart failure, hyperkalemia, hypotension, hypovolemia; African Americans; renal artery stenosis, renal disease, renal failure, renal impairment; autoimmune diseases, especially systemic lupus erythematosus (SLE).

Route & Dosage

Adult: PO 10 mg once/d, may increase up to 20–40 mg 1–2 times/d (max: 80 mg/d)
Child: PO 6–16 y, Start at 0.07 mg/kg (max 5 mg) once/d (max: 40 mg/d)
Geriatric: PO Initial 2.5–5 mg/d, may increase by 2.5–5 mg/d every 1–2 wk (max: 40 mg/d).

Heart Failure
Adult: PO 5–40 mg/d



Adverse Effects (1%)

CNS: Headache, dizziness, fatigue. CV: Hypotension, chest pain. GI: Nausea, vomiting, diarrhea, anorexia, constipation, intestinal angioedema. Hematologic: Neutropenia. Respiratory: Dyspnea, cough. Skin: Rash. Metabolic: Azotemia, hyperkalemia, increased BUN, and creatinine levels.


Drug: Indomethacin and other nsaids may decrease antihypertensive activity; potassium supplements, potassium-sparing diuretics may cause hyperkalemia; may increase lithium levels and toxicity.


Absorption: 25% absorbed from GI tract. Onset: 1 h. Peak: 6–8 h. Duration: 24 h. Distribution: Limited amount crosses blood–brain barrier; crosses placenta; small amount distributed in breast milk. Metabolism: Is not metabolized. Elimination: Excreted primarily in urine. Half-Life: 12 h.

Nursing Implications

Assessment & Drug Effects

Patient & Family Education

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug