Hypertension Lecture Notes

Vocabulary flashcards covering key terms, definitions, facts, classifications, lifestyle modifications, and specific antihypertensive agents (first-line and alternative) with their mechanisms of action (MOA), adverse drug reactions (ADRs), and special considerations for various patient populations based on the lecture notes.

Hypertension

A common chronic medical problem in the industrialized world, affecting over 100,000,000 Americans (1 in 3 adults), and a leading cause of CVD deaths.

Hypertension Risk Factor

Every increase of 20/10 mmHg in blood pressure doubles the risk of dying from stroke, heart disease or other vascular disease.

Lifetime risk of HTN at age 55 (normotensive)

Persons who are normotensive at age 55 have a 90% lifetime risk for developing hypertension.

Comorbidities of Hypertension

Common co-occurring conditions in HTN patients include current smoking, obesity, hypercholesterolemia, diabetes, and Chronic Kidney Disease (CKD).

Natural Course of Uncontrolled Hypertension

Can lead to stroke (hemorrhagic and ischemic), Coronary Heart Disease (angina, MI, CHF), Retinopathy (retinal infarcts/hemorrhages), and Nephropathy (Chronic Kidney Disease).

Normal Blood Pressure (ACC/AHA 2017)

Systolic <120 mmHg and Diastolic <80 mmHg.

Elevated Blood Pressure (ACC/AHA 2017)

Systolic 120-129 mmHg and Diastolic <80 mmHg.

Hypertension Stage 1 (ACC/AHA 2017)

Systolic 130-139 mmHg or Diastolic 80-89 mmHg.

Hypertension Stage 2 (ACC/AHA 2017)

Systolic ≥140 mmHg or Diastolic ≥90 mmHg.

Weight Reduction (Lifestyle Modification)

Reduces blood pressure, decreases total CHD risk, and should be pursued in combination with drug therapy for overweight/obese patients.

Alcohol Intake Limit (Lifestyle Modification)

Limit intake to 1 oz ethanol/day (2 drinks) in men and 0.5 oz ethanol/day (1 drink) in women; excessive intake can cause resistance to drug therapy.

Physical Activity (Lifestyle Modification)

Regular aerobic exercise (90-150 minutes/week), dynamic resistance exercise (90-150 minutes/week), and isometric resistance exercise (3 sessions/week) are effective in lowering BP.

Dietary Sodium Limit (Lifestyle Modification)

Optimal goal is <1500 mg/day, with at least a 1000 mg/day reduction to lower blood pressure.

Hydrochlorothiazide

A Thiazide Diuretic, a first-line antihypertensive agent.

Thiazide Diuretics MOA

Initially lower BP through diuresis, and chronically decrease peripheral vascular resistance; often used in combination therapy to offset compensatory sodium retention.

Thiazide Diuretics ADRs

Nausea/diarrhea, erectile dysfunction, sun sensitivity, and metabolic issues like hypokalemia, hyperglycemia, and hyperlipidemia (most ADRs are dose-related, limit dose to 25mg/day).

Thiazide Diuretics Contraindications

Anuria, and caution in pregnant women (hypoperfusion of fetus), diabetes, gout, and renal failure.

ACE Inhibitors (Agents)

Benazepril, Captopril, Enalapril, Lisinopril, Ramapril, and others.

ACE Inhibitors MOA

Blocks the conversion of Angiotensin I to Angiotensin II (a potent vasoconstrictor), decreases aldosterone secretion, and blocks degradation of bradykinin (natural vasodilators).

Specific Advantages of ACE Inhibitors

Beneficial in patients with heart failure and chronic kidney disease.

ACE Inhibitors ADRs

Hyperkalemia, acute kidney failure (

ACE Inhibitors Contraindication

Pregnancy.

Angiotensin II Receptor Blockers (ARBs)

Candesartan, Irbesartan, Losartan, Valsartan, and others.

ARBs MOA

Angiotensin II receptor antagonists, blocking the effects of Angiotensin II from RAA System and tissue sources; do not affect bradykinin levels (no cough).

ARBs ADRs

Orthostasis, much less angioedema than ACEi, and contraindicated in pregnancy (similar to ACEi).

Dihydropyridine Calcium Channel Blockers (CCBs)

Amlodipine, Felodipine, Nifedipine, and others, characterized by peripheral vasodilation effects.

Non-Dihydropyridine Calcium Channel Blockers (CCBs)

Diltiazem and Verapamil, characterized by effects on heart rate and contractility in addition to vasodilation.

Calcium Channel Blockers MOA

Blocks the influx of calcium across the cell membrane, leading to coronary and peripheral vasodilation; both types are equally effective for HTN, but have negative inotropic effects.

Dihydropyridine CCBs ADRs

Dizziness, flushing, headache, peripheral edema.

Non-Dihydropyridine CCBs ADRs

GI effects (anorexia, nausea), less peripheral edema than DHP CCBs, and constipation (especially with verapamil).

Aliskiren

A Direct Renin Inhibitor, an alternative antihypertensive agent.

Direct Renin Inhibitors MOA

Blocks renin's activity to convert angiotensinogen to angiotensin I, thereby inhibiting the RAA system.

Direct Renin Inhibitors ADRs

Orthostasis and angioedema, similar to ACE inhibitors and ARBs, and contraindicated in pregnancy.

Cardioselective Beta-Blockers

Atenolol, Metoprolol, Bisoprolol, Nebivolol; possess greater affinity for B1 receptors (heart and kidney).

Non-selective Beta-Blockers

Carvedilol, Labetalol, Propranolol, Nadolol; affect both B1 and B2 receptors.

Beta-Blockers MOA (HTN)

Though many physiologic effects are documented, the precise mechanism causing BP lowering is uncertain; cardioselective beta-blockers are generally preferred for HTN.

Beta-Blockers ADRs

Bradycardia, dizziness/drowsiness, bronchoconstriction in COPD/asthma patients; abrupt discontinuation can result in rebound HTN or increased heart rate (taper dose over 1-2 weeks).

Alpha Blockers

Prazosin, Terazosin, Doxazosin; reserved for patients with treatment-resistant hypertension.

Alpha Blockers MOA

Selective alpha-1 receptor antagonists in the peripheral vasculature, resulting in vasodilation and BP lowering.

Alpha Blockers ADRs

First-dose effect (dizziness, faintness, syncope; take before bedtime), sustained orthostatic hypotension (especially in elderly), CNS effects (lassitude, vivid dreams, depression), and priapism.

Central Alpha Agonists

Clonidine, Methyldopa; reserved for patients with treatment-resistant hypertension.

Central Alpha Agonists MOA

Reduces sympathetic outflow from the vasomotor center in the brain, decreasing heart rate, cardiac output, and blood pressure.

Central Alpha Agonists ADRs

Sodium and water retention (often need a diuretic), depression, high incidence of orthostatic hypotension, anticholinergic effects (sedation, dry mouth, urinary retention), and rebound hypertension with abrupt cessation.

Hypertension in Pregnant Women (Preferred Drugs)

Labetalol, long-acting nifedipine, and methyldopa.

Hypertension in Pregnant Women (Contraindicated Drugs)

ACE inhibitors, ARBs, and direct renin inhibitors due to risk to the fetus.

Hypertension in Elderly Patients (≥65 years)

Often present with isolated systolic hypertension; generally avoid central alpha agonists and peripheral alpha-blockers due to orthostasis risk, and start other drugs at lower doses.

Hypertension in Children and Adolescents

More common in obese children (lifestyle modifications important); secondary hypertension is more common, requiring work-up for kidney disease. ACEi, ARB, beta-blockers, CCBs, and thiazides are evidence-supported.