anti-hypertensives:
ace inhibitors
Written by Jun Yu Chen
Last Reviewed: May 2019
Review Due: May 2020
examples
Ramipril
Enalapril
Captopril
Lisinopril
mechanism of action
The renin-angiotensin-aldosterone system in the kidneys in the system has a primary role in controlling blood pressure. Angiotensinogen is a protein released by the liver. Renin, an enzyme released from the kidneys, converts angiotensinogen into angiotensin I. Renin is released when the kidneys detect a fall in blood pressure. Angiotensin-converting enzyme (ACE), an enzyme released from the lungs, converts angiotensin I to angiotensin II.
Angiotensin II has various effects to increase blood pressure:
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Sodium and water retention – this expands extracellular volume
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Aldosterone secretion – from posterior pituitary which increases water reabsorption, expanding extracellular volume
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Increased sympathetic nervous system action increases heart rate
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Vasoconstriction – indirect effects on raising blood pressure
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Hypertrophy – remodelling of the heart
Angiotensin-converting enzyme inhibitors inhibit ACE and so prevent the conversion from angiotensin I to angiotensin II.

indications
Hypertension
Heart Failure
Diabetic Nephropathy
Chronic Kidney Disease
Myocardial Infarction
Prevention of Cardiovascular Disease
side effects
Cough
Headache
Muscle Cramps
GI Upset (diarrhoea and vomiting)
Mild Skin Rash
Blurred Vision
Stomatitis
Syncope
Hyperkalaemia
Angioedema (more common in Afro-Caribbean patients)

Contraindications
Hypersensitivity to ACE Inhibitors
Acute Kidney Injury
Bilateral Renal Artery Stenosis
Pregnancy
Breastfeeding
dose adjustments
Hepatic Impairment
Ramipril is a prodrug, so patient requires monitoring in hepatic impairment
Renal Impairment
Check eGFR and electrolytes before and when increasing dose
interactions
Other Antihypertensives:
Calcium Channel Blockers
Beta-blockers
Angiotensin Receptor Blockers
Mineralocorticoid Receptor Antagonists
Allopurinol
NSAIDs (renal damage)
Anticoagulants
Diuretics (hyperkalaemia, hypotension)
Alcohol