Cardio 1: Diuretics and Blood Pressure

Cardio 1: Blood Pressure and Diuretics

• Two ways to increase blood pressure: increasing blood volume and vasoconstriction
• RAAS (Renin-Angiotensin-Aldosterone System) drugs:
  • ACE inhibitors: Lisinopril, Captopril
  • Angiotensin-II receptor blockers: Valsartan, Losartan
  • Angiotensin Receptor Neprilysin inhibitor: Sacubitril- Valsartan
• Diuretics:
  • Four types: Loop diuretics, Thiazide diuretics, Potassium-sparing diuretics, Osmotic diuretics
  • Furosemide: Administer early in the day to avoid nocturia; monitor potassium levels; can cause hypotension and ototoxicity

Furosemide

• Best taken early in the day to avoid nocturia
• Bumetanide is similar to Furosemide but works faster
• Not all diuretics cause hypotension as a side effect
• Furosemide must be administered slowly (20mg/min) via IV push to decrease the risk of ototoxicity
• Furosemide can lead to hypokalemia (especially in IV push)

Hydrochlorothiazide

• Educate patients on the use of sunblock due to increased photosensitivity
• Has a milder effect than Furosemide

Spirinolactone

• Spares potassium
• Blocks aldosterone in distal tubule, retains potassium, and excretes more sodium
• Often paired with other diuretics due to its mild effects
• Restrict potassium-rich foods to avoid hyperkalemia
• Can be used to treat acne and hirsutism in women due to its anti-androgen effects

Mannitol

• Similar structure to glucose
• Osmotic diuretic
• Serves as a sugary substance that water wants to dilute, pulling water out of tissues and into the blood
• Side effects: peripheral edema, dehydration
• Monitor intake and output, vitals, and electrolytes
• Not used to treat heart failure

Digoxin

• Cardiac glycoside
• Positive inotrope: increases the amount of calcium in heart muscles, leading to an increase in the force of heart muscle contraction, improving cardiac output
• Should be prescribed in heart failure palliative care settings
• Blocks Na/K pump
• Has a narrow therapeutic range
• Therapeutic range: 0.8-2ng/mL
• Signs of toxicity: confusion, fatigue, dizziness, blurry vision, N/V
• Hypokalemia can increase the risk of toxicity
• Antidote: Digoxin Immune Fab (Digibind or Digifab)

Calcium Channel Blockers

• Two groups: Dihydropyridines (Amlodipine, Clevidipine, Nicardipine) and Non-Dihydropyridines (Diltiazem, Verapamil)
• Suffix: -Dipine
• MOA: Blockade of calcium channels in blood vessels (Dihydropyridines) and heart muscles (Non-Dihydropyridines) causing a decrease in vascular resistance, blood pressure, and heart contraction
• Indications: SHARP (Subarachnoid Hemorrhage, Hypertension, Angina, Raynaud's phenomenon, Prinzmetal Angina)
• Side effects: Orthostatic hypotension, dizziness, constipation, flushing, headache, peripheral edema, gingival hyperplasia
• Avoid grapefruit juice, as it can cause severe hypotension
• Must be tapered off to avoid rebound hypertension

Beta Blockers

• Suffix: -olol
• Prototype drug: Metoprolol, Propranolol
• Check heart rate and systolic BP before administering
• Do not administer if heart rate is less than 60bpm and systolic BP is less than 100 mmHg
• Monitor diabetic patients closely, as beta blockers can mask tachycardia, a common symptom of hypoglycemia
• Indications: Hypertension, stable angina, chronic and compensated heart failure, dysrhythmias, anxiety, tachycardia
• Side effects: Bradycardia, heart blocks, breathing problems, lowered blood pressure, blood sugar masking

Nitrates

• Prototype drugs: Nitroglycerin, Isosorbide Mononitrate
• Suffix: -Nitro, -Nitrate
• MOA: Increase blood flow to heart muscles during injury or ischemia by vasodilating and relaxing the vessels, relieving the heart of added stress
• Indications: Acute chest pain, preventing chest pain, acute coronary syndrome
• Side effects: Flushing, headaches, hypotension
• Do not chew or drink grapefruit juice with nitrates
• Call 911 if acute chest pain persists

Alpha Blockers

• Prototype drug: Terazosin
• Alpha 1 blocker: Can cause severe orthostatic hypotension

Centrally Acting Alpha 2 Agonist Agents

• Prototype drug: Clonidine
• MOA: Decreases sympathetic response from brainstem to peripheral vessels, leading to vasodilation and lowered BP
• Indications: Hypertension
• Must be tapered over 2-4 days to avoid rebound hypertension
• Side effects: Drowsiness, decreased HR, dry mouth
• Educate patients to chew gum or hard candy to decrease dry mouth

Hydralazine

• Vasodilator of arterioles
• Decreases blood pressure
• Available in oral and IV forms
• Side effects: Reflex tachycardia, hypotension

HMG-CoA Reductase Inhibitors (Statins)

• Suffix: Statins
• MOA: Inhibit HMG-CoA reductase, a critical component of hepatic cholesterol synthesis
• Prototype drugs: Atorvastatin, Simvastatin, Rosuvastatin, Lovastatin, Pravastatin
• Side effects: Myopathy, rhabdomyolysis, diabetes, memory loss
• Pose a risk of teratogenicity during pregnancy
• Alternative medications: Bile sequestrant, Ezetimibe, Fibric acid derivatives

This quiz covers various aspects of diuretics, blood pressure, and the RAAS system. It includes questions on prototype drugs, diuretic effects, and more.