ACE inhibitors block ACE in the lungs from converting angiotensin I, activated when renin is released from the kidneys, to angiotensin II, a powerful vasoconstrictor. Blocking this conversion leads to decreased BP, decreased aldosterone secretion, a small increase in serum potassium levels, and sodium and fluid loss; increased prostaglandin synthesis also may be involved in the antihypertensive action.

Indications

Treatment of hypertension (alone or with thiazide type diuretics)

Treatment of heart failure (used with diuretics and digitalis)

Treatment of stable patients within 24 hr of acute MI to improve survival (lisinopril)Reduction in risk of MI, stroke, and death from CV causes (ramipril)

Treatment of left ventricular dysfunction post-MI (captopril, trandolapril)

Treatment of asymptomatic left ventricular dysfunction (enalapril)

Treatment of diabetic nephropathy (captopril)Unlabeled uses:

Renovascular hypertension, nondiabetic nephropathy, migraine prophylaxis, stroke prevention, heart failure, high risk of CAD, diabetes, chronic renal disease, scleroderma renal crisis

Contraindications and cautions

Contraindicated with allergy to the drug,

impaired renal function, heart failure, salt or volume depletion, lactation, pregnancy, history of angioedema, bilateral renal artery stenosis.

Adverse effects

CNS: Dizziness, headache, fatigue

CV: Tachycardia, angina pectoris, MI, Raynauds syndrome, heart failure, hypotension in salt or volume depleted patients

Dermatologic: Rash,pruritus, alopecia, pemphigoid like reaction, scalded mouth sensation, exfoliative dermatitis, photosensitivity

GI: Gastric irritation, aphthous ulcers,peptic ulcers, dysgeusia, cholestatic jaundice, hepatocellular injury, anorexia, constipation

GU: Proteinuria, renal insufficiency, renal failure,polyuria, oliguria, urinary frequency

Hematologic: Neutropenia, agranulocytosis, thrombocytopenia, hemolytic anemia, pancytopenia, hyperkalemia

Other: Cough,malaise, dry mouth, lymph- adenopathy, angioedema

Interactions

Drug-drug

Increased risk of hypersensitivity reactions with allopurinol

Decreased anti- hypertensive effects with indomethacin

Increased risk of hyperkalemia if combined with aldosterone blockers, potassium-sparing diuretics, aliskiren, cyclosporine, potassium supplements

Drug-food

Decreased absorption of selected drugs if taken with food

Drug-lab test

False positive test for urine acetone