Hypertension Medication Overview

Overview

This lecture provides a concise review of hypertension medication classes, their key characteristics, how to select agents based on individual factors, and important prescribing tips.

Major Antihypertensive Drug Classes

• Four main first-line classes: thiazide diuretics, ACE inhibitors, ARBs, and calcium channel blockers (CCBs).
• Beta blockers are not considered first-line unless specific indications exist; other agents are used as fourth or fifth-line options.
• All four main classes are roughly equally effective in lowering blood pressure, but patient response varies.

Drug Selection Criteria

• Initiate monotherapy with one first-line class; beta blockers not usually first-line except for specific conditions.
• Age: Patients <50 years typically respond better to ACE inhibitors or ARBs.
• Race: Black patients respond best to thiazide diuretics or long-acting CCBs; all classes are options for Caucasian patients.
• Combine CCB with ACE inhibitor or ARB if monotherapy insufficient in black patients.

Comorbid Conditions Influencing Drug Choice

• BPH: Use alpha blocker
• Essential tremor: Use beta blocker
• Hyperthyroidism: Use beta blocker
• Migraine: Use beta blocker or CCB
• Osteoporosis: Use thiazide diuretic
• Raynaud’s: Use CCB
• Atrial fibrillation/flutter: Use beta blocker or CCB
• Post-MI: Use ACE inhibitor, ARB, beta blocker, or aldosterone antagonist

Contraindications and Drug Avoidance

• Do not use ACE inhibitor in angioedema or during pregnancy.
• Avoid non-selective beta blockers in bronchospastic disease.
• Avoid methyldopa in liver disease.
• Avoid certain drugs in specific conditions: beta blockers/central alpha 2 agonists (depression), thiazides/loops (gout), ACE/ARB/renin inhibitors/aldosterone antagonists (hyperkalemia), thiazides (hyponatremia), ACE/ARB/renin inhibitors (renal vascular disease).
• Avoid ACE inhibitors and ARBs together in combination therapy.

Approaches When Monotherapy Fails

• If no response to initial drug, either increase dose (prefer one-step increase) or change drug class after 4-6 weeks.
• Most blood pressure response occurs at lower-to-moderate doses; increasing dose yields diminishing returns and more side effects.
• Two or three drugs at half-standard dose may be more effective and cause fewer side effects than high-dose monotherapy.

Drug Class Overviews & Side Effects

• Calcium Channel Blockers: Two types—dihydropyridine (prefer for hypertension, ex: amlodipine, procardia), non-dihydropyridine (affect heart, ex: verapamil, diltiazem). Side effects: dihydropyridine—edema, headache; non-dihydropyridine—constipation.
• ACE Inhibitors: Block conversion of angiotensin I to II, lowering BP. Side effects: cough, hyperkalemia, reduced GFR, hypotension.
• ARBs: Block angiotensin II receptors; similar effects/side effects as ACE inhibitors but less cough.
• Thiazide Diuretics: Cause volume loss, effective in elderly/black patients. Side effects: electrolyte imbalances, hyperglycemia, hyperuricemia.
• Beta Blockers: Lower HR and BP by blocking adrenergic receptors. Side effects: dizziness, fatigue, cold extremities, GI issues.

Additional Prescribing Tips

• Take antihypertensive meds in the morning due to lower nocturnal blood pressure.

Key Terms & Definitions

• Thiazide Diuretic — increases urine output by affecting kidney tubules, lowering blood volume.
• ACE inhibitor — blocks angiotensin-converting enzyme, reducing blood vessel constriction.
• ARB (Angiotensin Receptor Blocker) — prevents angiotensin II from tightening blood vessels.
• Calcium Channel Blocker (CCB) — inhibits calcium entry into heart/vessel cells, causing relaxation.
• Beta Blocker — reduces heart rate and output by blocking beta-adrenergic receptors.

Action Items / Next Steps

• Review drug dose ranges and side effect profiles for each antihypertensive class.
• Apply patient-specific factors (age, race, comorbidities) when selecting antihypertensive therapy.
• Avoid contraindicated drugs in at-risk patient groups.