Antihypertensives

Antihypertensive drugs

• lowers bp

• to prevent stroke, heart attack, and kidney disease

Angiotensin Converting Enzyme Inhibitors (ACE Inhibitors)

MOA
blocks conversion of Angiotensin 1 to Angiotensin 2 - vasodilation - low bp

• Angiotensin 1 (precursor)

• Angiotensin 2 (active hormone) a vasoconstrictor; narrows blood vessels, increasing bp

ACE - pril

Enalapril

Captopril

Lisinopril

Ramipril

Angiotensin Receptor Blockers (ARB)

MOA

blocks Angiotensin 2 receptors - vasodilation - low bp

ARB - sartan

Losartan

Telmisartan

Olmesartan

Valsartan

Candesartan

Calcium Channel Blockers (CCB)

MOA

blocks calcium entry in the smooth muscles - vasodilation - low bp

• Role of calcium on smooth muscles (initiates and regulates muscle contraction)

CCB - dipine

Amlodipine

Felodipine

Nimodipine

Nifedipine

Isradipine

Verapamil

Diltiazem

Beta Blockers

MOA

blocks beta-adrenergic receptors - low HR & low heart contraction - low bp

• role of beta-adrenergic receptors (mediate effects of epinephrine and norepinephrine = relaxation)

Beta - olol

Propranolol

Metoprolol

Bisoprolol

Labetalol

Atenolol

Direct Vasodilators

MOA

directly dilates the blood vessels - low bp

• fast acting drug used for emergencies

Direct - zine

Hydralazine

Minoxidil

Diazoxide

Sodium Nitroprusside

• Common: Hydralazine and Nitroprusside only

Diuretics

promotes diuresis - increased production of urine

MOA

remove excess sodium and water from blood vessels - low blood volume and low bp

Diuretics example

K+ sparring (stores potassium) - spironolactone

K+ wasting (wastes potassium) - furosemide & hydrochlorothiazides

Central Alpha - 2 Agonists

MOA

stimulates alpha 2- adrenergic receptors (Medulla oblongata and brain stem) - low norepinephrine secretion (muscle relaxes) - vasodilation - low bp

• alpha 2- adrenergic receptors (inhibits norepinephrine release from sympathetic nerves (fight or flight)

• norepinephrine (stimulates heartbeat)

Central Alpha - 2 Agonists Examples

Clonidine (Catapres) - sublingual

Methldopa

Alpha Blockers

MOA

blocks alpha-adrenergic receptors (blood vessels) - low contraction of muscles - vasodilation - low bp

Alpha - zosin

Terazosin

Doxazosin

Tamsulosin

General Considerations

• Hypotension: DO NOT GIVE when systolic BP is 90 and below. (bp lower than 90 and even HR of 60 bpm = shock)

• Orthostatic hypotension: change position SLOWLY

• Rebound hypertension: DO NOT STOP medication ABRUPTLY (can increase bp)

ACE Inhibitors

used for:

• Long term treatment

• Heart failure

• MI

• Prevent renal damage (nephropathy) - Diabetic patients

adverse effects

• Angioedema (swelling in the mouth; tingling sensation; leads to airway obstruction = difficulty of breathing) STOP MEDS

• Hyperkalemia (Na+ decrease, K+ increase)

• Fetotoxicity (fetal mortality; hypoplasia of organs; avoid on pregnant clients)

• Dysgeusia (loss of taste = when taking captopril)

Hyperkalemia

• Aldosterone causes Na+ retention and K+ loss

• ACE Inhibitors inhibits Aldosterone

  • Effect is reverse. Na+ loss and K+ retention = Hyperkalemia

ACE Inhibitors Nursing Considerations

• Report signs of Angioedema (tingling of lips, itching = airway obstruction)

• Monitor K+ levels (spasms, weakness = signs of hyperkalemia)

• Avoid K+ supplements (ACE Inhibitors increases K+)

• Avoid for pregnant client (risk of fetotoxicity; baby becomes abnormal)

• Cough is expected (blocks enzyme that breaks down bradykinin; a substance that can irritate the airways and cause coughing)

ARB’s

same adverse effects and considerations

Calcium Channel Blockers works on

• Effects on the peripheral blood vessels (away from the heart; arms and legs)

• Dilation of blood vessels especially the ARTERIES

• Except for Verapamil and Diltiazem (for HEART)

Calcium Channel Blockers Nursing Considerations

• Avoid GRAPEFRUIT - toxicity (chemicals in fruit can get the metabolizing of medicine making it stay in the body for longer or shorter of time)

• Check for edema in the legs (to assess the severity of the side effect and to determine if adjustments to medication or dosage are needed)

Beta Blockers

Affects:

• Beta-1 receptors (Heart and Kidney)

• Beta-2 (smooth muscles)

• Blocks EPINEPHRINE and NOREPINEPHRINE neurotransmitters = low bp

Adverse effects:

• bronchoconstriction - due to blocking of beta-2 receptors (lung is a smooth muscle so due to blockage it constricts leading to bronchoconstriction and bradycardia)

• bradycardia

DO NOT GIVE IF:

• BP 90/60 mmHg below

• HR 60 bpm below

Beta Blockers Nursing Considerations

• Diabetic patients - mask symptoms of hypoglycemia

  • need to check for palpations and tachycardia

  • monitor blood glucose levels

• Avoid clients with ASTHMA and COPD (constricted already, by adding beta blockers it will become more constricted = difficulty of breathing)

  • Risk for bradycardia and bronchoconstriction

Direct Vasodilators is given during ___

Hypertensive Emergencies (fast effect)

Direct Vasodilators Nursing Considerations

• Hydralazine - tachycardia, dizziness, check also for severe hypotension

• Nitroprusside - severe hypotension

  • check signs for CYANIDE TOXICITY (too much nitroprusside)

• confusion, altered levels of consciousness, bradycardia

• check for BP - severe hypotension can lead to organ failure (due to fast effect)

Alpha blockers Nursing Considerations

• Monitor BP closely

• Organ failure can happen if bp is TOO LOW