confused about ace inhibitors?

[IHeartPeds87]

Hi there! I am trying to understand something about ace inhibitors and am having a difficult time. I would appreciate any help/insight on this subject matter!

Oka, so for ace inhibitors- an example being lisinopril....let's say I had to give this medication to a patient in clinical. I understand that I would check the blood pressure and potassium levels before giving the medication.

My clinical instructor mentioned that we would also be checking the creatnine before giving lisinopril, because the ace could cause renal failure (I believe that's what she said, but again I could be wrong because I don't understand this).

I don't understand what the purpose is of checking creatnine before giving an ace inhibitor, because, and again correct me if i'm wrong: aren't ace inhibitors given to diabetics to help prevent the onset of diabetic nephropathy? so if ace inhibitors harm the kidneys then why do we give them to prevent the onset of diabetic nephropathy?

thanks for your help! :)

[BostonFNP, APRN]

People with very low renal perfusion may have a deterioration of renal function secondary to vasodilation of the efferent renal arterioles. This is almost entirely limited to patients with significant renal stenosis and/or heart failure.

There may be a small bump in creatinine in other patients which is not clinically significant.

[Summer Days]

One of the side effects of ace inhibitors is potassium retention. Checking creatinine level lets you know if the kidneys are working (a better indictor is creatinine clearance) and are able to excrete excess potassium induced by ace inhibitors. If you've done the fluids and electrolytes chapter you will know that high potassium level precipitates cardiac dysrhythmias and we don't want this to happen. So we check Cr level and if its high, the ace inhibitor is withheld.