Angioedema may occur rarely with ACEIs (may involve head and neck or intestine). African-Americans and patients with idiopathic or hereditary angioedema may be at increased risk. Patients with history of airway surgery may have higher risk of airway obstruction. Use in previous angioedema associated with ACEI therapy contraindicated. Cholestatic jaundice, which may progress to fulminant hepatic necrosis, may occur. A dry, hacking, nonproductive cough usually occurs within first few months of treatment (should generally resolve within 1-4 weeks after discontinuation of ACEI). Hyperkalemia may occur with ACEIs (risk factors include renal dysfunction, diabetes mellitus, concomitant use of potassium-sparing diuretics, potassium supplements and/or potassium containing salts). Anaphylactic/anaphylactoid reactions can occur with ACEIs. Symptomatic hypotension with or without syncope can occur (usually with first several doses). Another ACEI, captopril, associated with rare cases of agranulocytosis, neutropenia, or leukopenia with myeloid hypoplasia. Patients with renal impairment are at high risk of developing neutropenia. Patients with both renal impairment and collagen vascular disease (e.g. systemic lupus erythematosus) are at even higher risk of developing neutropenia. May be associated with deterioration of renal function and/or increases in serum creatinine, particularly in low renal blood flow (e.g. renal artery stenosis, heart failure) whose glomerular filtration rate is dependent on efferent arteriolar vasoconstriction by angiotensin II. Use with caution in severe aortic stenosis (may reduce coronary perfusion resulting in ischemia). Caution in cardiovascular disease (ischemic heart disease or cerebrovascular) due to potential consequences posed by falling blood pressure (e.g. MI, stroke). Use with caution in collagen vascular disease, especially with concomitant renal impairment (may be at increased risk for hematologic toxicity). Use with caution in hypertrophic cardiomyopathy and outflow tract obstruction (reduction in afterload may worsen symptoms). Use with caution in unstented unilateral/bilateral renal artery stenosis, and in pre-existing renal insufficiency. ACEIs can cause injury and death to developing fetus when used in 2^nd^ and 3^rd^ trimesters. Use with caution before, during, or immediately after major surgery (use of ACEIs perioperatively will blunt angiotensin II formation and may result in hypotension).