Medicine & USMLE

ACE Inhibitors

Cardio Drugs - Blood Pressure
  1. ACE Inhibitors
  2. Angiotensin II Receptor Blockers (ARBs)
  3. Beta Blockers: Mechanisms and Clinical Uses
  4. Beta Blockers: Side Effects
  5. DHP Calcium Channel Blockers
  6. Hydralazine
  7. Aliskiren
  8. Nitroprusside
  9. Alpha-1 Blockers
  10. Clonidine


ACE Inhibitors (ACEIs) are medications that end in -pril, including lisinopril, captopril, ramipril, and enalapril. ACE inhibitors work by blocking angiotensin converting enzyme or ACE, which blocks the conversion of angiotensin I to its active counterpart, angiotensin II. Reduced angiotensin II levels cause vasodilation, and reduced downstream signaling of aldosterone further reduces blood volume. The overall effect of treatment with an ACE inhibitor is lowering of blood pressure. Clinically, ACE inhibitors are used to treat hypertension and heart failure. Side effects include a dry cough, angioedema, and hyperkalemia. Notably, ACE inhibitors are teratogenic and should not be used during pregnancy.

Key Points

  • ACE Inhibitors
    • Key Drugs (-pril endings)
      • Lisinopril
      • Captopril
      • Enalapril
    • Mechanism
      • Inhibits Angiotensin Converting Enzyme (ACE)
        • Prevents the conversion of angiotensin I to angiotensin II (vasoconstrictor)
        • Less angiotensin II decreases peripheral arterial resistance, decreases aldosterone secretion, increases sodium and water excretion at kidneys, and lowers blood pressure
    • Clinical Use
      • Hypertension
      • Heart failure
      • Myocardial Infarction
    • Side Effects and Adverse Reactions
      • Dry Cough
        • Dry cough produced as a result of increased bradykinin
        • Expected side effect, usually harmless
      • Angioedema
        • Swelling of eyes, mouth, and face due to edema
        • Life-threatening, most serious side effect
      • Teratogenic
        • Should not be used during pregnancy
        • Reduces placental blood flow
      • Hyperkalemia
        • Teach patient to avoid potassium supplements, potassium salt substitute, and potassium-sparing diuretics
        • Increased water and sodium excretion and potassium retention
      • Hypotension
        • Closely monitor patient’s blood pressure
        • Instruct patient to get up slowly to avoid dizziness associated with orthostatic hypotension
      • Do not use over the counter (OTC) medications (cold, cough, allergy) unless directed by provider