Diuretics Pharmacology PDF

Diuretics - Pharmacotherapeutics: Drug that reduces fluid volume in body and increases urine output o Uses: HTN, CHF, Cirrhosis, renal disease, increased intracranial pressure, pulmonary edema, glaucoma. - Pharmacodynamics: Block sodium and water reabsorptio...

Diuretics - Pharmacotherapeutics: Drug that reduces fluid volume in body and increases urine output o Uses: HTN, CHF, Cirrhosis, renal disease, increased intracranial pressure, pulmonary edema, glaucoma. - Pharmacodynamics: Block sodium and water reabsorption in the nephron, sending more sodium into the urine to be excreted o Increases urine output (diuresis) ▪ Degree of diuresis depends on the part of tubule affected by the drug and potency of the drug - Mechanism of Action: - Nursing Process: o Assessment: health hx, baseline labs (electrolytes, CBC, liver and renal studies) o Baseline Assessment: weight, vital signs, breathing sounds, cardiac monitoring, edema o Planning and interventions: ensure therapeutic effects (increased urine output, decreased BP; Monitor daily weights and intake and output) o Minimize adverse effects: Monitor vital signs, electrolyte levels, BUN (8-20) and creatinine (0.6-1.3) levels; monitor nutritional status; watch for signs of gout or photosensitivity ▪ If BUN is high think dehydration o Ensure patient understanding o 3 goals appropriate for pt on diuretics ▪ Increased output ▪ Decreased weight ▪ Decreased edema Q: Most diuretics act in the body to cause: loss of sodium Loop Diuretics (Prototype: Furosemide aka Lasix) - Purpose: blocks chloride pump in the ascending loop of Henle, decreases reabsorption of sodium and chloride, causes diuresis even with severe renal impairment - Indications: o Pulmonary edema o Edema caused by liver, cardiac, or kidney disease or HTN o To treat hypercalcemia related to kidney stone formation o Given PO, IV or IM - Adverse Effects: o Dehydration o Hypotension o Electrolyte imbalance ▪ Hypokalemia ▪ Hyponatremia ▪ Hypomagnesemia ▪ Hypocalcemia ▪ Hyperglycemia ▪ Hyperuricemia o Ototoxicity - Nursing interventions/Edu o Daily weight/strict I&O/Edema o Monitor electrolyte levels o Monitor blood pressure o Watch for orthostatic hypotension o Monitor for tinnitus o Educate clients to eat high potassium foods o Monitor glucose and uric acid o Use cautiously in pts with DM or gout o Do not give late in day Q: When providing care to a pt who is receiving a loop diuretic, the nurse would determine the need to regularly monitor....? A: Potassium Thiazide Diuretics (HCTZ) - Purpose: o Block the chloride pump to keep chloride and sodium in the tubule to be excreted in urine o Promotes diuresis in healthy kidneys o Mild diuretic compared to loop diuretics - Therapeutic uses: o First choice for HTN o Treatment of mild-mod edema, r/t heart failure or liver or kidney disease - Adverse Effects: o Dehydration o Hypotension o Electrolyte imbalances ▪ Hypokalemia ▪ Hyperglycemia ▪ Hypercalcemia ▪ Hyperuricemia - Nursing interventions/education: o Daily weight/I&O/check skin turgor o Monitor electrolyte levels, glucose and uric acid o High potassium diet o Do not give during pregnancy o Take early in day o Increased risk for lithium or digoxin toxicity Q: Thiazide diuretics are considered mild diuretics because: A: they have little or no effect on electrolyte levels Potassium-sparing diuretics (Prototype: Spironolactone aka Aldactone) - Purpose: o Blocks action of aldosterone, causing excretion of sodium and water o Promotes retention of potassium - Therapeutic uses: o Usually combined with other diuretics o Heart failure patients or high risk for hypokalemia  o Given orally - Adverse Effects: o Hyperkalemia/arrhythmias o Endocrine effects: ▪ Hirsutism, gynecomastia, irregular menses - Nursing interventions/education o Monitor potassium o Never administer potassium supplements with this drug o Regular insulin to treat hyperkalemia (pulls potassium from blood to the cell) o Do not give to clients with renal failure o Do not give with ACE inhibitors o Avoid salt substitutes with potassium o Monitor BP and weight Q: A client was prescribed Furosemide as an adjunct treatment for HTN. What objective data could you collect to determine the therapeutic effectiveness of this drug? A: BP Q: What electrolyte value is most important to check before administering a diuretic? A: potassium Q: The nurse is concerned about potassium loss when a diuretic is prescribed for a pt with ascites and edema. What diuretic may be ordered that spares potassium and prevents hypokalemia? A: Spironolactone Q: The nurse is educating an 80 year old patient diagnosed with heart failure about his medication regimen. What should the nurse teach this client about the use of oral diuretics? A: take the diuretic in the morning to avoid interfering with sleep Drugs affecting the urinary tract SNS (fight or flight) vs PNS (relaxation) Urinary tract antispasmodics, anticholinergics - Prototype: Oxybutynin - Purpose: o Competes with Ach for binding with muscarinic receptors o Blocks parasympathetic activity - Therapeutic uses: o Reduces muscle spasms of the bladder and urinary tract o Treats symptoms of overactive bladder - Adverse effects o Anticholinergic effects ▪ Can’t see: blurred vision ▪ Can’t pee: urinary retention ▪ Can’t spit: dry mouth ▪ Can’t shit: Constipation o Sympathetic effects ▪ Dilated pupils, decreased peristalsis, etc. o CNS effects ▪ Nervousness, anxiety, apprehension - Nursing interventions/client education o Rule out obstructive urinary tract problems o Contraindicated for clients with glaucoma, myasthenia gravis or acute hemorrhage o Can be administered oral, transdermal or topical Medication for OAB, Beta-3 Adrenergic agonists - Prototype: Mirabegron (Myrbetriq) - Purpose: o Beta-3 adrenergic agonist drug that targets beta-3 receptors in the bladder o Inhibits the signaling pathways that tell the brain the bladder should be emptied - Therapeutic issues:  o Treats OAB by relaxing the bladder muscle and increasing its bladder’s capacity without urinary urgency - Adverse effects: o HTN o UTI o Headache o Nasopharyngitis o URI o CALL PROVIDER IF THERE IS SWELLING OF THE UPPER AIRWAY, FACE, LIPS OR TONGUE - Nursing intervention/education o Contraindicated for clients with uncontrolled HTN, caution for clients taking anticholinergic med for OAB (urinary retention) o Digoxin and Warfarin effects are increased when taken with Mirabegron o Can be administered oral Non-obstructive urinary retention, Cholinergic, Muscarinic agonist - Prototype: Bethanechol (urecholine) - Purpose: o Direct acting parasympathomimetic that bind to muscarinic cholinergic receptors that cause PSNS stimulation o Mimics the effects of acetylcholine - Therapeutic uses: o Treats non-obstructive urinary retention in patient with atony of the bladder - Adverse effects: o PSNS stimulation o Salivation, sweating o Abdominal cramping o Hypotension/bradycardia o Cholinergic crisis ▪  - Nursing interventions/education o Contraindicated for patients with intestinal obstruction or recent bowel surgery o Do not give in patients with asthma, epilepsy, Parkinson’s, hyperthyroidism, PUD or bradycardia o Take 2 hour before or 2 hours after meals o Monitor I&O o Atropine is the antidote (Muscarinic antagonist) Medications for BPH: 5-alpha reductase inhibitor (Prototype: Finasteride) Purpose: blocks the enzyme DHT from converting to testosterone Therapeutic uses: Shrinks prostate Adverse effects: o May cause ED o Teratogenic to male fetus o Increase risk of prostate cancer o Decreases PSA levels Alpha-adrenergic receptor antagonists (Prototype: Tamsulosin) - Purpose: blocks alpha 1 receptors, relaxes smooth muscle in the bladder neck and prostatic urethra - Therapeutic uses: relieves obstruction and increase flow of urine - Adverse effects: o Little to no effect on blood pressure, like other alpha blockers o Abnormal ejaculation o Headache, dizziness o Avoid taking until after cataract surgery