ACE inhibitors (-pril) and ARBs (-sartan) do almost the same job, so exams love asking about the few ways they’re different.

What they both do

Both work on the renin-angiotensin system to relax blood vessels and lower blood pressure. You’ll see them for high blood pressure, heart failure, after a heart attack, and to protect the kidneys in diabetes.

The difference that matters

• ACE inhibitors (lisinopril, enalapril, captopril) can cause a dry, nagging cough because of bradykinin buildup. That’s the most common reason patients get switched.
• ARBs (losartan, valsartan, irbesartan) block the same system at a different step, so the cough is much less common. That’s usually the switch.

What they share (and what you’ll be tested on)

• High potassium. Check the K before giving. Teach patients to avoid salt substitutes, which are often potassium chloride.
• Kidney function. Watch creatinine, especially when starting.
• Low BP and dizziness, especially with the first dose. Rise slowly.
• Angioedema. Swelling of the lips, tongue or throat. It’s an emergency. More associated with ACE inhibitors but possible with both.
• Not in pregnancy. Both can harm the fetus.

The NCLEX version

“A client started lisinopril last week and reports a dry cough that won’t stop. What does the nurse expect?” A switch to an ARB. And the scary one: “A client on lisinopril has a swollen tongue.” That’s airway first, stop the drug, call for help.

Study aid only. Always follow your program, your facility’s policies, and a current drug reference.