This document discusses ACE inhibitors, including their mechanism of action, indications for use, adverse effects, and nursing considerations. ACE inhibitors work by inhibiting the angiotensin converting enzyme and reducing vasoconstriction and sodium retention. They are used to treat hypertension, heart failure, myocardial infarction, nephropathy, and diabetes. Common adverse effects include hypotension, cough, and hyperkalemia. Nurses should monitor patients for these effects and educate them about medication use and signs of side effects.
2. Learning Objectives
Discuss the reason for using ACE Inhibitors and the
mechanism by which they work.
Identify three common adverse effects of using ACE
Inhibitors.
Identify three considerations for educating a patient
on the use of ACE Inhibitors
3. ACE Inhibitors
ACE Inhibitors are medications that belong in the
class of medications known as antihypertensive
medications.
ACE Inhibitors work on the Renin-Angiotensin-
Aldosterone System
4. Renin-Angiotensin-Aldosterone System
A system which works to increase blood pressure when the
pressure within the kidneys drops.
As a result of low blood pressure and/or oxygenation in the
nephron, renin is released from the juxtaglomerular cells.
Renin travels to the liver via the cardiovascular system and
combines with angiotensinogen to form angiotensin I.
Angiotensin I travels through the cardiovascular system
and arrives at the lungs where it is changed into
Angiotensin II.
The alveoli use Angiotensin Converting Enzyme also
known as kinase II to cause this conversion.
(Karch, 2012, pg. 671)
5. Renin-Angiotensin-Aldosterone System cont.
Angiotensin II is a powerful vasoconstrictor which
causes a rise in peripheral resistance and increases
pressure.
Angiotensin II works to increase the release of
aldosterone from the adrenal glands.
Aldosterone causes renal retention of sodium and
water, which further increases blood pressure by
increasing volume. (Karch, 2012, pg. 671)
6. Mechanism of Action for ACE Inhibitors
ACE Inhibitors work in the lungs to inhibit
Angiotensin Converting Enzyme from turning
Angiotensin I into Angiotensin II.
These medications cause an increase of
bradykinin, which inhibits kinase II, another name for
Angiotensin Converting Enzyme. (Lehne, 2007, pg.
464)
Blood Pressure is decreased due to a decrease in blood
volume, peripheral resistance, and cardiac load.
ACE Inhibitors, inhibit vasoconstriction and release of
aldosterone which inhibits the retention of sodium
and water.
7. Indications For Use
Hypertension-used especially for malignant
hypertension and hypertension secondary to renal
arterial stenosis.
Benefits of Using an ACE Inhibitor
Do not interfere with cardiovascular reflexes
Do not interfere with patients who have asthma like beta-
blockers
Do not decrease potassium levels.
Do not cause lethargy, weakness and sexual dysfunction.
“ACE inhibitors reduce the risk of cardiovascular mortality
caused by hypertension.” (Lehne, ,2007, pg. 465)
8. Indications For Use cont.
Heart Failure
By decreasing arteriolar tone region blood flow to the heart
improves.
By decreasing afterload, cardiac output increases.
Venous dilation increases causing a decrease in pulmonary
congestion and peripheral edema.
Dilates the vessels of the kidneys increasing renal flow and
helps to excrete sodium and water. This helps to decrease
edema and blood volume.
Prevents pathologic changes in the heart that result from
reducing the angiotensin II levels in the heart.
(Lehne, 2007, pg. 465)
9. Indications For Use cont.
Myocardial Infarction (MI)
Decreases the chance of heart failure after an MI.
Should be given for 6 weeks post MI. If heart failure occurs it
should be considered for permanent use.
Nephropathy
Slows renal disease of diabetic or nondiabetic origins
Decreases glomerular filtration pressure.
10. Indications For Use cont.
Type 2 Diabetes
Decreases morbidity in high risk patients.
Increased levels of angiotensin II have a correlation to type 2
diabetes.
ACE inhibitors increase kinin levels, which increase
production of prostaglandins and nitric oxide.
Prostaglandins and nitric oxide improve muscular sensitivity
to insulin. (Solski & Longyhore, 2008, pg. 936)
May preserve pancreatic function and prevent onset of
diabetes especially with people who have hypertension.
12. Adverse Effects
First-Dose Hypotension
Usually occurs with initial dose.
Worse in patients with severe hypertension, or are on
diuretics, or are sodium or volume depleted.
Cough
“Persistent, dry, irritating, nonproductive cough can develop
with all ACE inhibitors.” (Lehne, 2007, pg. 466)
Due to rise in bradykinin which occurs due to inhibition of
kinase II.
Occurs in 5-10% of patients and is more common in women
and the elderly.
13. Adverse Effects cont.
Hyperkalemia
Potassium levels rise due to the inhibition of
aldosterone, which causes potassium to be retained by the
kidneys.
Renal Failure
Can cause renal insufficiency in people who have bilateral
renal artery stenosis, because dropping the pressure in the
renal arteries in these patients can cause glomerular
filtration to fail.
Fetal Injury
In the second and third trimesters a fetus can experience
hypotension, hyperkalemia, skull hypoplasia, renal
failure, and death.
14. Drug Interactions
Antihypertensive agents
Can cause an increased effect of medications especially with
diuretics.
Potassium increasing medications
Cause an increased risk of hyperkalemia due to the suppression of
aldosterone.
Lithium
Increases to risk of lithium toxicity.
Allopurinol
Increases hypersensitivity to medication
NSAIDS
Reduce antihypertensive effects of medication.
15. Nursing Considerations
Encourage lifestyle changes
Weight loss
Quit smoking
Decrease alcohol intake
Encourage exercise to help lower blood pressure
Monitor Renal Function
BUN, Creatinine, and Potassium levels
Monitor for decreased fluid volume which can bottom our
blood pressure
Excessive sweating
Diarrhea
Vomiting
Dehydration
16. Nursing Considerations cont.
Monitor for 1st-dose hypotension
May have to stop other antihypertensive medications at initiation of
ACE inhibitors.
May have to give these medications in lower doses going forward.
Discontinue diuretics for 2-3 days prior to starting an ACE inhibitor.
Monitor BP for several hours and if patient becomes hypotensive lay
patient supine and consider discussing IV bolus of saline with the
MD.
Educate Patient
Teach the patient about the medication including name adverse
effects, drug interactions.
Teach the patient about the signs of hypotension, hyperkalemia, and
renal failure. If patient is taking lithium discuss the signs of lithium
toxicity.
17. Test Questions
1. Which of these patients would most likely be treated
with an ACE inhibitor?
a) A 38-year old women who has become hypertensive in
the last trimester of her pregnancy.
b) A 78-year old man who just had a heart attack and is in
renal failure.
c) A 60-year old man who is a diabetic and suffers from
hypertension.
d) A 72-year old female with a history of hypertenstion
who comes to the ER in septic shock.
18. Test Questions
2. Which statement by a patient taking ACE inhibitors
demonstrates the patient’s understanding of the
medication?
a) “I don’t need to exercise because the medication will
make me better.”
b) “If I feel weak or faint I should take my
medication, because it will make me feel better.”
c) “I can use salt substitutes instead of the real thing.”
d) “If I develop a cough that does not go away I should
call my doctor.”
19. Test Questions
1. Which of these lab values would be a
contraindication for taking an ACE inhibitor?
a) Potassium 3.3
b) Potassium 5.6
c) BUN 10
d) Creatinine 1.2
20. Test Answers with Rationale
1. c is the correct answer. a, b, and d all have
contraindications for giving an ACE inhibitor.
2. d is the correct answer. a is wrong because exercise
should be encouraged. b is wrong because weakness
and syncope are signs that the patient may be
hypotensive. c is wrong because salt substitutes are
high in potassium and should be used with caution
in patients on ACE inhibitors.
3. a is the right answer. Hyperkalemia is a
contraindication for ACE inhibitors.
21. References
Karch, A. (2011). Focus on nursing pharmacology (5th
ed.). Philadephia, PA: Wolters Kluwer | Lippincott
Williams & Wilkins.
Lehne, R. (2007). Pharmacology for nursing care (6th ed.).
St. Louis, MO: Saunders|Elsevier.
Solski, L. V. & Longyhore. (2008). Prevention of type 2
diabetes mellitus with angiotensin-converting-
enzyme inhibitors. American Journal of Health-
System Pharmacy, 65(10): 935-40.
Waterfield, J. (2008). ACE inhibitors: use, action, and
prescribing rationale. Nurse Prescribing, 6(3): 110-4.
