Common adverse drug reactions (=1% of patients) include: hypotension, cough, hyperkalemia, headache, dizziness, fatigue, nausea, renal impairment.

A persistent dry cough is a relatively common adverse effect believed to be associated with the increases in bradykinin levels produced by ACE inhibitors, although the role of bradykinin in producing these symptoms remains disputed by some authors. Patients who experience this cough are often switched to angiotensin II receptor antagonists.

Rash and taste disturbances, infrequent with most ACE inhibitors, are more prevalent in captopril and is attributed to its sulfhydryl moiety. This has led to decreased use of captopril in clinical setting, although it is still used in scintigraphy of the kidney.

Renal impairment is a significant adverse effect of all ACE inhibitors, and is associated with their effect on angiotensin II-mediated homeostatic functions such as renal blood flow. Renal blood flow is affected by Angiotensin II because it vasoconstricts the efferent arterioles of the glomeruli of the kidney, thereby increasing glomerular filtration rate (GFR). Hence, by reducing angiotensin II levels, ACE inhibitors reduce GFR, a marker of renal function. Specifically, ACE inhibitors can induce or exacerbate renal impairment in patients with renal artery stenosis. This is especially a problem if the patient is also concomitantly taking an NSAID and a diuretic - the so-called "triple whammy" effect - such patients are at very high risk of developing renal failure.

ACE inhibitors may cause hyperkalemia, because angiotensin II increases aldosterone release. Since aldosterone is responsible for increasing the excretion of potassium, ACE inhibitors ultimately cause retention of potassium.

Some patients develop angioedema due to increased bradykinin levels. There appears to be a genetic predisposition towards this adverse effect in patients who degrade bradykinin slower than average.

Quinapril drug information Cardiac glycoside Pharmacodynamics and clinical effects Thiazide side effects Phytosterols Mechanisms of hypokalemia Indications and usage Inhibitor effects Cardenolides Adverse effects Thiazide Digoxin Warnings Inhibitor adverse effects Clinical pharmacology Ace inhibitor Digoxin clinical use Quinapril faq Precautions Steroid