Diuretics: Loop and Thiazide

Loop Diuretics – Furosemide (Lasix)

• Use: Treats edema from congestive heart failure, liver disease, kidney disease, and hypertension
• Action: Blocks sodium, potassium, and chloride reabsorption in the ascending loop of Henle, increasing diuresis
• Side effects: Hypokalemia, dehydration, electrolyte imbalance, orthostatic hypotension, ototoxicity (especially with rapid IV), and hyperglycemia
• Nursing: Monitor electrolytes, renal function (BUN, creatinine), and fluid balance; assess for dehydration, orthostatic hypotension, and electrolyte imbalances; advise taking in the morning

Thiazide Diuretics – Hydrochlorothiazide (Hydrodiuril)

• Use: First-line for hypertension and edema from mild heart failure or renal disease
• Action: Stops sodium and chloride reabsorption in the distal tubule, increasing urine
• Side effects: Hypokalemia, hyperglycemia, hyperuricemia (can worsen gout), dehydration, dizziness, and weakness
• Nursing: Monitor blood pressure, electrolytes (especially potassium and sodium), and blood glucose; encourage a potassium-rich diet

Potassium-Sparing Diuretics – Spironolactone (Aldactone)

• Use: Treats hypertension, heart failure, conditions causing hypokalemia, and hyperaldosteronism
• Action: Aldosterone antagonist; inhibits sodium retention and potassium excretion in the distal tubule, causing mild diuresis and preserving potassium
• Side effects: Hyperkalemia, gynecomastia (in males), menstrual irregularities, and dizziness
• Nursing: Monitor potassium, renal function, and blood pressure; tell patients to avoid potassium-rich foods and supplements
• Foods high in potassium: Bananas, oranges, tomatoes, spinach, potatoes, and avocados

Androgens – Testosterone

• Use: For hypogonadism, delayed puberty, and hormone replacement in males; also for some female breast cancers
• Action: Binds to androgen receptors, boosts male characteristics and muscle growth
• Side effects: Acne, liver dysfunction, fluid retention, mood changes, high cholesterol, and cardiovascular risks
• Nursing: Monitor liver function, lipid levels, hemoglobin, and hematocrit; educate about misuse risks
• Anabolic steroids: High misuse potential among athletes for muscle growth, which can result in cardiovascular issues, liver damage, and psychological problems

PDE5 Inhibitors – Sildenafil (Viagra)

• Use: Treats erectile dysfunction and pulmonary arterial hypertension
• Action: Inhibits phosphodiesterase type 5 (PDE5), increasing cyclic GMP, relaxing smooth muscle, and improving penis blood flow
• Side effects: Headache, flushing, hypotension, priapism (prolonged erection), and vision disturbances
• Nursing: Contraindicated with nitrates (can cause severe hypotension); educate on usage and interactions

Nasal Decongestants – Pseudoephedrine

• Use: Provides temporary relief from nasal congestion due to colds, allergies, and sinus infections
• Action: Alpha-adrenergic agonist causing vasoconstriction in nasal mucosa, which reduces swelling and congestion
• Side effects: Hypertension, insomnia, dizziness, tachycardia, and restlessness
• Nursing: Use cautiously in patients with hypertension or cardiovascular disease; avoid prolonged use (>3 days) to prevent rebound congestion

First Generation H1 Receptor Antagonists – Diphenhydramine

• Use: Treats allergic reactions, motion sickness, and insomnia
• Action: Blocks H1 receptors, reducing histamine-induced allergic symptoms
• Side effects: Drowsiness, dry mouth, dizziness, and urinary retention
• Nursing: Warn about sedation and avoid alcohol; use caution in elderly patients

Adrenergics – Albuterol

• Use: For acute bronchospasm, asthma, and COPD
• Action: Beta-2 adrenergic agonist that relaxes bronchial smooth muscles, causing bronchodilation
• Side effects: Tachycardia, palpitations, tremors, nervousness, and paradoxical bronchospasm
• Nursing: Monitor heart rate, teach proper inhaler technique, and warn against overuse

Isoniazid (INH)

• Use: First-line treatment for active and latent TB
• Action: Inhibits mycolic acid synthesis in TB bacteria, which leads to bacterial cell death
• Side effects: Hepatotoxicity, peripheral neuropathy, and gastrointestinal upset
• Nursing: Monitor liver function; recommend Vitamin B6 supplementation

Rifampin

• Use: Treats TB and provides prophylaxis for meningococcal disease
• Action: Inhibits bacterial RNA synthesis
• Side effects: Hepatotoxicity, red-orange discoloration of body fluids, and GI upset
• Nursing: Monitor liver function, warn about body fluid discoloration, and advise against alcohol

Henke's Med-Math

• Key topics: Dosage calculations, IV flow rates, weight-based dosing, and conversions
• Formulas:
  • IV Flow Rate (mL/hr) = Total Volume (mL) / Time (hr)
  • Dosage Calculation = (Desired Dose / Available Dose) × Volume
  • Body Weight Dosage = mg/kg × Patient Weight (kg)