ACE inhibitors
Blocking the enzyme that makes angiotensin II, so vessels relax.
Also called angiotensin-converting enzyme inhibitors and ACEIs.
Class card
- Drugs
- Lisinopril, Ramipril, Enalapril and Captopril
- Used for
- High blood pressure, as a first-line drug
- Heart failure
- After a heart attack, to protect the heart
- Diabetic kidney disease with protein in the urine
- Known for
- Dry, persistent cough
- Swelling of face, lips, tongue or throat (angioedema)
- High potassium (hyperkalemia)
- Name stems
- -pril
5 cards: the class, and each drug in it.
Mechanism of action
How do ACE inhibitors work?
They block angiotensin-converting enzyme (ACE), so less angiotensin I is turned into angiotensin II. Arterioles relax, aldosterone release falls (potassium rises a little) and renin climbs because angiotensin II no longer holds it back. ACE also breaks down bradykinin; the bradykinin that builds up is thought to cause the dry cough and angioedema.
The drugs
ACE inhibitors with a card
- LisinoprilThe ACE inhibitor that is neither a prodrug nor metabolized: the kidneys alone clear it, so kidney function decides how long it stays.
- RamiprilBesides treating blood pressure, it is licensed to cut heart attack, stroke and cardiovascular death in high-risk people aged 55 or over.
- EnalaprilUsed alone it lowers blood pressure less in black patients, who also get angioedema more often.
- CaptoprilShort-acting and sulfhydryl-containing; best known for taste loss, rash, proteinuria and, in kidney or collagen disease, neutropenia.
Uses
What are ACE inhibitors used for?
- High blood pressure, as a first-line drug
- Heart failure
- After a heart attack, to protect the heart
- Diabetic kidney disease with protein in the urine
Side effects
Side effects of ACE inhibitors
- Dry, persistent coughKnown for
- Swelling of face, lips, tongue or throat (angioedema)Known forSerious
- High potassium (hyperkalemia)Known forSerious
- Low blood pressure, worst after the first dose
- Worsening kidney functionSerious
- Harm to the unborn baby (fetal toxicity)Serious
- Change or loss of taste
- Rash
- Liver injury beginning as cholestatic jaundice (rare)Serious
- Low white cell count (neutropenia), rareSerious
What the class has in common. Each drug's card has its own, and Known for marks what an exam expects you to know.
Watch for
Cautions
- Pregnancy: stop as soon as it is detected, as they can injure or kill the developing baby.
- Contraindicated after ACE inhibitor angioedema, in hereditary or idiopathic angioedema, and within 36 hours of sacubitril.
- Check potassium and kidney function; potassium-sparing diuretics, potassium supplements, NSAIDs and kidney disease raise the risk.
- Renal artery stenosis or salt and water depletion: kidney function and blood pressure can drop sharply.
Remember them
A way to remember them
CAPTOPRIL
- C
- Cough
- A
- Angioedema
- P
- Potassium up
- T
- Taste change
- O
- hypOtension
- P
- Pregnancy: avoid
- R
- Rash
- I
- Increased renin
- L
- Lower angiotensin II
The letters of captopril, itself an ACE inhibitor, spell out the class's main effects and the pregnancy rule.
A mnemonic widely used in teaching
Name stems
-pril means ACE inhibitor
Prodrugs such as enalapril and ramipril are turned into active forms named -prilat (enalaprilat). Don't confuse it with -tril: sacubitril blocks neprilysin, not ACE.
- Every drug name stem
Don't mix them up
Classes easily confused with these
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- ACE Inhibitor (NCI Thesaurus)
- Lisinopril tablets: label (DailyMed)
- Captopril tablets: label (DailyMed)
- Ramipril capsules: label (DailyMed)
- Guideline for the pharmacological treatment of hypertension in adults (WHO)
- Lisinopril (NHS)
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Blood pressure
Practice ACE inhibitors with the other classes in this group: what each drug is, how it works, what it treats and what it's known for.
Start Practicing