Chapter 28: Diuretic Drugs - Study Guide Columns

CHAPTER 28: DIURETIC DRUGS High-Yield Nursing Study Guide • Based on the uploaded Chapter 28 review deck • Thiazide diuretics can cause low potassium. • For the exam: HCTZ + digoxin = low potassium → increased risk of digoxin toxicity and dysrhythmias. • Potassium levels should be monitored closely. 5. Potassium-Sparing Diuretic — Spironolactone • Memory: POTASSIUM-SPARING = POTASSIUM STAYS. Class Prototype Must Know Carbonic anhydrase inhibitor Acetazolamide (Diamox) Metabolic acidosis; low potassium; increased blood glucose in diabetic patients • Main concern: high potassium (hyperkalemia). Loop diuretic Furosemide (Lasix) Rapid diuresis; low potassium; orthostatic hypotension • The review identifies interactions with lithium, potassium supplements, nonsteroidal anti-inflammatory drugs, and angiotensin-converting enzyme inhibitors. Thiazide diuretic Hydrochlorothiazide (HCTZ) Hypertension; low potassium; digoxin interaction • Potassium supplements and angiotensin-converting enzyme inhibitors increase the risk of high potassium. Potassium-sparing diuretic Spironolactone (Aldactone) High potassium; peaked T waves; interactions Osmotic diuretic Mannitol Cerebral edema; decreased intracranial pressure; intravenous infusion with filter • Monitor for muscle weakness, cardiac dysrhythmias, and peaked T waves on an electrocardiogram. 6. Osmotic Diuretic — Mannitol • Memory: MANNITOL = BRAIN. • Used to decrease cerebral edema and intracranial pressure. • Administer by intravenous infusion using a filter because the solution can crystallize. • Inspect the solution for crystals before administration. 1. Carbonic Anhydrase Inhibitor — Acetazolamide • The review states to warm the solution if crystallized. 7. Hypokalemia — Low Potassium • Memory: ACID + LOW POTASSIUM. • The review identifies metabolic acidosis and low potassium as important effects. • In a patient with diabetes, monitor for increased blood glucose and glucose in the urine. • Loop + thiazide + carbonic anhydrase inhibitor are the diuretic groups emphasized as causing low potassium. • Signs tested in the review: muscle weakness, anorexia/loss of appetite, and lethargy/fatigue. • Other signs listed: nausea, confusion, low blood pressure, and cardiac dysrhythmias. • Effectiveness may diminish in 2–4 days. • Monitor for drowsiness and low potassium. • Shortness of breath, constipation, and ringing in the ears were not the primary answers for the review question. 2. Loop Diuretic — Furosemide 8. Fluid Volume Assessment • Memory: LOOP = LOSE POTASSIUM. • Rapid onset and quick diuretic action; useful when immediate fluid removal is needed, including pulmonary edema. • Best answer: intake and output records + daily weights. • Important risks: low potassium, dehydration, orthostatic hypotension, and electrolyte imbalance. • Weigh at the same time each day, on the same scale, with similar clothing. • Daily weights help detect small fluid changes. • 1 kilogram = 1 liter of fluid. • The review states loop diuretics can remain effective even with severely impaired kidney function. • The review describes an effect lasting about 2 hours. 9. Older Adult Safety • Older adults have increased risk for volume depletion, electrolyte imbalance, orthostatic hypotension, dizziness, fainting, and falls. 3. Furosemide Patient Teaching • Teach extra caution when standing and changing positions. • Take a once-daily diuretic in the early morning to reduce nighttime urination. • Change positions slowly to prevent dizziness and falls from orthostatic hypotension. • Sit on the edge of the bed before standing; use rails when walking. • Report dizziness promptly. • Significant weight gain should be reported promptly rather than waiting for a routine visit. 4. Thiazide Diuretic — Hydrochlorothiazide • Monitor for dehydration and electrolyte imbalance. 10. Dosage Calculations • Furosemide liquid: Ordered 60 milligrams; available 40 milligrams per 5 milliliters. Answer = 7.5 milliliters. • Pediatric dose: 44 pounds ÷ 2.2 = 20 kilograms. 20 kilograms × 2 milligrams per kilogram = 40 milligrams. • For the pediatric question, the review says to verify the calculation with another nurse. • Hydrochlorothiazide (HCTZ) is used for hypertension in the review. Chapter 28: Diuretic Drugs Study Guide • Page 1 ■ EXAM TRAPS — KNOW THESE COLD Question clue Think / Answer Which diuretic causes high potassium? Spironolactone Which diuretics cause low potassium? Loop, thiazide, carbonic anhydrase inhibitor Cerebral edema / decreased intracranial pressure? Mannitol How is mannitol given? Intravenous infusion with a filter STAT Source: Uploaded Chapter 28: Diuretic Drugs – Practice Questions review deck. The guide preserves the tested points from that source rather than adding unrelated material. When should a once-daily diuretic be taken? Early morning Best fluid-volume assessment? Intake/output + daily weights Hydrochlorothiazide + digoxin? Low potassium → increased digoxin toxicity risk Peaked T waves? High potassium → think spironolactone Dizziness when standing? Orthostatic hypotension Muscle weakness + anorexia + lethargy? Low potassium ■ 15 PRACTICE-QUESTION ANSWERS FROM THE REVIEW 1. Increased blood glucose levels 2. Spironolactone 3. Intravenous infusion using a filter 4. Change positions slowly to prevent dizziness and falls 5. Rapid onset with quick diuretic action 6. Digoxin 7. Intake/output records and daily weights 8. Early morning hours 9. Thiazide diuretics (hydrochlorothiazide) 10. Osmotic diuretics (mannitol) 11. Use extra caution when standing because of fall risk 12. Lithium; potassium supplementation; nonsteroidal anti-inflammatory drugs; angiotensin-converting enzyme inhibitors 13. Muscle weakness; loss of appetite; tiredness/fatigue 14. 7.5 milliliters per dose 15. 40 milligrams total dose ■ ABBREVIATION / SYMBOL KEY K■ Potassium HCTZ Hydrochlorothiazide IV Intravenous PEG Percutaneous endoscopic gastrostomy I&O; Intake and output ICP Intracranial pressure ECG Electrocardiogram NSAIDs Nonsteroidal anti-inflammatory drugs ACE inhibitors Angiotensin-converting enzyme inhibitors mg Milligrams kg Kilograms mL Milliliters mg/kg Milligrams per kilogram Immediately / at once Chapter 28: Diuretic Drugs Study Guide • Page 2