Which one of the following is NOT true in relation to angiotensin converting enzyme (ACE)  inhibitor?
ACEI are used for the treatment of hypertension, CHF, evolving MI, diabetic nephropathy, diabetic retinopathy, non-diabetic renal disease and also in scleroderma crisis. These drugs reduce proteinuria in diabetic as well as non-diabetic renal disease and also prevent the manifestations of scleroderma crisis which are mediated by angiotensin II.
Most frequent adverse effect associated with these agents is dry cough. It can be reduced by iron supplements and asprin. ACEI can also cause angioedema. Both cough and angioedema is due to elevated levels of bradykinin.
These can cause hyperkalemia if used along with other agents causing elevation of serum potassium (like potassium sparing diuretics).
Other adverse effects include rashes, dysguesia (altered taste sensation), and acute renal failure (if used in bilateral renal artery stenosis). It is important to distinguish between acute renal failure and a normal predictable rise in serum creatinine secondary to ACE inhibitor therapy. An increase in serum creatinine upto 30% within 2-5 days can be expected in most patients started on ACE inhibitors. It stabilizes in 2-3 weeks and is reversible on stopping drug therapy. These drugs are contra-indicated in pregnancy (teratogenic in second half of pregnancy) and when serum creatinine is more than 3.5 mg/dl.

All patients with diabetic nephropathy, whether hypertensive or normotensive, deserve ACE inhibitor therapy.  Deterioration of retinopathy in diabetics also appears to be retarded by ACE inhibitors.
Reference: Essentials of Medical Pharmacology Eighth Edition KD  TRIPATHI page no 535
May cause hyperkalaemia in diabetic patients
Contraindicated in pregnancy
Contraindicated in diabetic nephropathy
NSAIDs may impair its hypotensive effect