Mnemonic

Antihypertensive Classes

A memory aid for the main antihypertensive drug classes and their side effects.

Expansion

ACE inhibitors, calcium channel blockers, thiazides, then spironolactone or beta blockers

Mnemonic

“ACD”, the UK stepwise approach:

  • A - ACE inhibitor or Angiotensin receptor blocker
  • C - Calcium channel blocker
  • D - thiazide-like Diuretic (indapamide)

Step 1: A if under 55 or diabetic; C if over 55 or of black African or Caribbean family origin, in whom renin levels are lower.

Step 2: A + C (or A + D). Step 3: A + C + D.

Step 4, resistant hypertension: add spironolactone if potassium is 4.5 or below, or an alpha or beta blocker if above.

“A for the young, C for the old, and never A alone in the black African population.”

Beta blockers are no longer first line for uncomplicated hypertension, but remain indicated with angina, heart failure or after infarction. ACE inhibitors and ARBs are contraindicated in pregnancy, where labetalol, nifedipine and methyldopa are used.

Expansion

Class Examples Key adverse effects
ACE inhibitors Ramipril, lisinopril Dry cough (bradykinin), hyperkalaemia, angioedema, renal impairment, teratogenic
Angiotensin receptor blockers Losartan, candesartan As above but no cough
Calcium channel blockers Amlodipine (dihydropyridine) Ankle oedema, flushing, headache
Verapamil, diltiazem (rate limiting) Bradycardia, constipation; never with a beta blocker
Thiazide-like diuretics Indapamide, bendroflumethiazide Hyponatraemia, hypokalaemia, gout, hyperglycaemia
Spironolactone Hyperkalaemia, gynaecomastia
Beta blockers Bisoprolol Fatigue, bradycardia, bronchospasm, masks hypoglycaemia
Alpha blockers Doxazosin Postural hypotension

Stepwise approach

  • Step 1: ACE inhibitor or ARB if under 55 or diabetic; calcium channel blocker if over 55 or of African or Caribbean family origin, where renin levels are typically lower
  • Step 2: combine the two
  • Step 3: add a thiazide-like diuretic
  • Step 4 (resistant hypertension): spironolactone if potassium is 4.5 or below, otherwise an alpha or beta blocker

Verapamil with a beta blocker is the combination to avoid absolutely, since both slow the atrioventricular node and can cause complete heart block or asystole.