Hypertension Treatment

• Hypertension is generally treated with specific drug classes, per AHA guidelines based on patient comorbidities.

ABCD's of Hypertension Treatment

• ACE inhibitors/ARBs
• Beta Blockers
• Calcium Channel Blockers
• Diuretics

Diuretics

• Thiazides are preferred for initial treatment of uncomplicated hypertension.
• Thiazides and loops reduce volume, reduce peripheral vascular resistance over time, and affect blood pressure.
• Loop diuretics should be used for patients who require greater diuresis effect than thiazides, or for those with a low glomerular filtration rate.
• Potassium sparing diuretics balance loss of K+ from loops or thiazides.

ACE Inhibitors

• ACE Inhibitors end in "pril"
• Examples include: Captopril (Capoten), Lisinopril (Zestril).
• They are used for hypertension, heart failure, and diabetic nephropathy.
• ACE Inhibitors block the production of angiotensin II, dilating arterioles, reducing blood volume, and reducing pathologic heart and blood vessel changes.
• ACE Inhibitors increase levels of bradykinin, causing vasodilation.
• Administer orally
• Administer with food (captopril 1 hour pre meal)
• Excreted by the kidney
• Adverse effects includes: First dose hypotension, cough, hyperkalemia, renal failure, fetal injury, angioedema, and neutropenia with Captopril.
• Medications to watch out for Durg Interactions: diuretics, other antihypertensive agents, drugs that increase potassium levels, lithium, and NSAIDs.
• Monitor B/P
• Educate on symptoms
• With cough, notify prescriber if bothersome, persistent
• Watch supplements, salt subs
• If pregnant – consult prescriber, should not take

Angiotensin Receptor Blockers

• Angiotensin Receptor Blockers end in "sartans"
• Examples include: Losartan (Cozaar).
• Uses: hypertension, heart failure, and slow diabetic nephropathy.
• They block the action of angiotensin II at receptor sites in arterioles and some venous, causing dilation.
• ARBs causes adrenals to decrease release of aldosterone, and help prevent pathologic changes in cardiac structure.
• ARBs are administered orally.
• Adverse effects: angioedema, fetal harm, and renal failure (renal artery stenosis).

Aldosterone Antagonists

• Examples include: Eplerenone (Inspra) and Spironolactone (Aldactone).
• Uses: hypertension and heart failure.
• Action: block aldosterone receptors and promote excretion of Na and water, K retention, and prevent/reverse effects of aldosterone on cardiovascular structure and function.
• Administer orally
• Adverse effects: Hyperkalemia
• Drug interactions: inhibitors of CYP3A4, drugs that raise potassium levels, and lithium

Beta Adrenergic Antagonists

• Beta Adrenergic Antagonists includes "olols,” “alols" "-ilols"
• 3 groups includes: First generation (nonselective agents, beta 1,2), Second generation (cardioselective, beta 1), and Third generation (vasodilating beta blockers, can be cardioselective plus alpha or non-cardioselective plus alpha)
• First generation Nonselective agent includes: Propranolol (Inderal)
• Second generation (cardioselective, beta 1) includes: Metoprolol (Toprol)
• Third generation (vasodilating beta blockers, can be cardioselective plus alpha or non-cardioselective plus alpha) includes: Labetalol, Carvedilol
• Uses: hypertension, angina, cardiac dysrhythmias, MI, heart failure
• Blockade of beta 1 receptors in heart, and Blockade of alpha 1 receptors prevent vasoconstriction
• Administer orally, IV
• Adverse effects: bradycardia, reduced cardiac output, AV heart block, rebound cardiac excitation with abrupt withdrawal, and sexual dysfunction
• Medications to avoid: Sick sinus syndrome, AV block

Calcium Channel Blockers

• Uses: treatment of hypertension, angina and dysrhythmias
• Action: Prevent the entry of calcium through gated pores
• Vascular smooth muscle in arterioles prevents contraction which promotes relaxation and dilation
• Heart: Myocardium causes negative inotropic effect, reduces force of contraction. SA node reduces SA node discharge to decreased heart rate. AV node suppresses AV node discharge to decreases AV conduction.
• Calcium channel blockers and beta-adrenergic antagonists have similar effects on cardiac function like decreasing heart rate, decrease contractility, and decrease AV conduction.
• 2 types of Calcium Channel Blockers includes: Dihydropyridones, and Non-dihydropyridones
• Dihydropyridones includes: nifedipine (Procardia)
• Non-dihydropyridones includes: Phenylalkylamine - verapamil (Calan), and Benzothiazepine – diltiazem (Cardiazem)
• Nifedipine (Procardia) is used for essential hypertension and angina
• The effects of Nifedipine (Procardia) blocks calcium channels, vascular smooth muscle causes vasodilation, reflex effect increase in heart rate, contractility (transient, more common with rapid acting dosages).
• Administer orally
• Adverse effects includes: reflex tachycardia, flushing, dizziness, headache, peripheral edema, chronic eczematous rash (older patients)
• Verapamil (Calan), Diltiazem (Cardizem) Blocks calcium channels in blood vessels and heart, and it is used for hypertension, angina, dysrhythmias.
• Administer: orally, IV
• Adverse effects: constipation, edema of ankles/feet, dizziness, facial flushing, and headache
• Interactions: digoxin, beta blockers, grapefruit juice
• Use with caution for patients with CHF, AV blocks, and sick sinus syndrome
• Report symptoms of shortness of breath, weight gain, and slow heart rate
• A diuretic may be added to reduce edema if needed.
• Non-dihydropyridines: Educate on adequate fiber, fluids and exercise to reduce risk of constipation.
• Dihydropyridines: Reflex tachycardia, beta blocker may need to be added-sustained release formulations are preferred, dont crush or chew.
• Watch for drug interactions: digoxin, beta blockers, grapefruit juice.

Direct Acting Vasodilators

• Direct Acting Vasodilators dilate of vessels, used for essential HTN, HTN crisis, angina, heart failure and MI
• Arterioles - reduces afterload (arterial resistance), decreases cardiac workload, increases cardiac output and tissue perfusion
• Veins - reduces preload, reduces cardiac work, cardiac output, and tissue perfusion
• Both - reduces preload and afterload
• Adverse effects: Venous dilators - orthostatic hypotension – increased risk for falls, Arteriole and venous dilators - reflex tachycardia, fluid retention, and Nitroprusside – toxic accumulation of cyanide, thiocyanate
• Hydralazine (Apresoline) - selective dilation of arterioles
• Nitroprusside (Nipride) – dilation of arteries and veins

A Note About Hypertensive Crisis

• Hypertensive crisis occurs when Diastolic B/P exceeds 120mm Hg, and there is likelihood of end organ damage
• Medications include: Sodium nitroprusside (Nipride)
• Direct acting vasodilator – dilating arterioles and vein smooth muscles

Hypertension in Pregnancy

• Pre-eclampsia includes: B/P above 130/90, and Proteinuria of 300 mg or more in 24 hours
• Eclampsia
• Seizures
• Risk factors includes: chronic hypertension, diabetes, collagen vascular disorders, previous history of pre-eclampsia, and black race
• Risks for Mom includes: seizures, renal failure, pulmonary edema, stroke, death
• Risks for Baby includes: intrauterine growth restriction, prematurity, and death

Hypertension in Pregnancy/Mild

• Near term – induction. Earlier in term - bed rest, antihypertensives, and anticonvulsant

Severe

• Delivery
• Lower blood pressure with labetalol 20 mg bolus over 2 minutes repeated in 10 minute intervals up to 300 mg
• Magnesium sulfate – seizure prophylaxis
• Administer 4-6 gm IV loading dose
• 5 gm injection into each buttock
• Continuous IV infusion – 1-2 gm/hour or 5 gm IM every 4 hours
• Monitor levels and presence of patellar reflex for target range, magnesium level should be 4-7 mEq/L

Questions cover thiazide diuretics mechanism, loop diuretics, electrolyte imbalance, and primary hypertension drug classes like ACE inhibitors/ARBs. Also covers Angiotensin receptor blockers (ARBs). Intended to test knowledge of hypertension pharmacotherapy.