What are the different classes of medications used to treat hypertension?

Different Classes of Medications for Hypertension Treatment

The primary antihypertensive medication classes used in clinical practice include thiazide and thiazide-like diuretics, angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), calcium channel blockers (CCBs), and beta-blockers, with the first four considered first-line agents for most patients with hypertension. 1, 2

First-Line Antihypertensive Classes

Thiazide and Thiazide-like Diuretics

• Act by inhibiting sodium and chloride reabsorption in the distal convoluted tubule, reducing blood volume and vascular resistance 1
• Examples include hydrochlorothiazide, chlorthalidone (with stronger evidence for cardiovascular outcomes), and indapamide 1, 3
• Particularly effective in Black patients and older adults 4, 5
• May cause electrolyte disturbances (hypokalemia), hyperglycemia, and hyperuricemia 3

Angiotensin-Converting Enzyme (ACE) Inhibitors

• Block conversion of angiotensin I to angiotensin II, reducing vasoconstriction and aldosterone secretion 1
• Examples include lisinopril, enalapril, and ramipril 6, 7
• Particularly beneficial in patients with diabetes, chronic kidney disease with proteinuria, and heart failure 5, 6
• Common side effects include dry cough and, rarely, angioedema; can cause hyperkalemia 5

Angiotensin Receptor Blockers (ARBs)

• Block angiotensin II receptors, preventing vasoconstriction and aldosterone release 1
• Examples include losartan, valsartan, and candesartan 8, 7
• Similar benefits to ACE inhibitors but with better tolerability (no cough) 5
• Particularly useful in patients with diabetes and kidney disease 8, 9

Calcium Channel Blockers (CCBs)

• Block calcium entry into vascular smooth muscle and cardiac cells, causing vasodilation 1
• Two main types: dihydropyridines (amlodipine, nifedipine) that primarily affect blood vessels and non-dihydropyridines (diltiazem, verapamil) that also affect cardiac conduction 5
• Particularly effective in Black patients and older adults 4, 5
• Side effects include peripheral edema, headache, and flushing for dihydropyridines; constipation and heart block for non-dihydropyridines 10

Second-Line and Special Situation Antihypertensive Classes

Beta-Blockers

• Block beta-adrenergic receptors, reducing heart rate, contractility, and renin release 1
• Examples include metoprolol, carvedilol, and atenolol 4
• Not recommended as first-line therapy for uncomplicated hypertension due to less favorable outcomes compared to other classes 1, 4
• Indicated for patients with concurrent coronary artery disease, heart failure, or post-myocardial infarction 4, 10

Mineralocorticoid Receptor Antagonists

• Block aldosterone receptors, promoting sodium and water excretion and potassium retention 5
• Examples include spironolactone and eplerenone 11
• Useful as add-on therapy in resistant hypertension 11
• Require monitoring for hyperkalemia, especially when combined with ACE inhibitors or ARBs 5

Alpha-1 Blockers

• Block alpha-1 adrenergic receptors, causing vasodilation 11
• Examples include doxazosin and prazosin 11
• May be useful in men with benign prostatic hyperplasia 5
• Can cause orthostatic hypotension, especially with first dose 11

Direct Vasodilators

• Relax vascular smooth muscle directly 12
• Examples include hydralazine and minoxidil 12
• Generally used as last-line agents due to significant side effects and need for multiple daily dosing 12
• Can cause reflex tachycardia and fluid retention 12

Central-Acting Agents

• Stimulate central alpha-2 receptors, reducing sympathetic outflow 11
• Examples include clonidine and methyldopa 11
• Generally reserved for resistant hypertension due to side effects 11
• Can cause sedation, dry mouth, and rebound hypertension if stopped abruptly 11

Combination Therapy Approach

• Most patients with hypertension will eventually require at least two medications from different classes 1, 9
• Initial combination therapy is recommended for stage 2 hypertension (≥160/100 mmHg) 4
• Preferred combinations include:
  • ACE inhibitor or ARB + thiazide diuretic 2, 9
  • ACE inhibitor or ARB + CCB 2, 9
  • CCB + thiazide diuretic 2
• Combinations to avoid: ACE inhibitor + ARB (increases adverse effects without additional benefit) 1, 5

Population-Specific Considerations

• For Black patients: thiazide diuretics or CCBs are more effective as initial therapy than ACE inhibitors or ARBs 11, 4
• For patients with diabetes and albuminuria: ACE inhibitor or ARB should be included 5, 9
• For patients with chronic kidney disease and proteinuria: ACE inhibitor or ARB is recommended 8, 9
• For older adults: consider starting with lower doses and careful monitoring for orthostatic hypotension 5

Common Pitfalls to Avoid

• Using ACE inhibitor + ARB combinations increases adverse effects without additional benefit 1, 5
• Underdosing medications before adding additional agents 5
• Failing to consider ethnicity in medication selection (ACE inhibitors and ARBs less effective in Black patients) 4, 5
• Not monitoring for electrolyte abnormalities, especially when using diuretics, ACE inhibitors, or ARBs 5
• Overlooking the need for more aggressive initial therapy in patients with markedly elevated blood pressure 4, 5