NURS 1950: Pharmacology 1

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 Diuretics work in the kidney at various sites of the nephron  Can interfere with the action of aldosterone causing loss of sodium ◦ Where goes sodium, so goes water 5

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 What happens with diuretics ◦ Decrease excess water ◦ Loop diuretics + 0.9% NaCl = loss of calcium ◦ Decrease excess NaCl ◦ Decrease cerebral edema (Mannitol) ◦ Decrease increased IOP (Diamox) 8

 Mannitol is an osmotic diuretic (a sugar); ◦ in the brain, its presence causes water to be drawn to it  Works the same way in the eye: ◦ the excess intraocular fluid is drawn to the mannitol in the hyperosmotic plasma 9

◦ Diamox very weak diuretic  Useful in treating glaucoma 10

◦ Aminophylline ◦ Theophylline ◦ Caffeine ◦ Theobromine  Diuretic effect from improved blood flow to kidney  Generally not used for diuretic effect 11

 Action of the thiazides ◦ Act on the distal tubules of the kidney  Block reabsorption of sodium and chloride ions from the tubule  The unreabsorbed Na and Cl ions pass into the collecting ducts, taking water with them  Thiazides have antihypertensive properties because of direct vasodilation effect on peripheral arterioles ◦ Expected outcomes from treatment  Decreased edema and improvement of symptoms RT excess fluid accumulation  Reduction in BP 12

 Assessments ◦ Mental status ◦ Diabetics require baseline blood glucose ◦ Assess hearing ◦ Assess for symptoms of acute gout  SE to expect: orthostatic hypotension ◦ Usually in initial stages of treatment ◦ Teach client safety measures 13

 SE to report ◦ GI irritation, N/V, constipation ◦ Electrolyte imbalance, dehydration ◦ Hyperuricemia ◦ Hyperglycemia ◦ Hives, rash  Thiazides can interact with ◦ Digoxin, corticosteroids ◦ Lithium, NSAIDs ◦ Oral hypoglycemic agents 14

 Thiazides can interact with ◦ Digoxin, corticosteroids ◦ Lithium, NSAIDs ◦ Oral hypoglycemic agents 15

 Thiazide diuretics include ◦ Bendroflumethiazide (Naturetin) ◦ Chlorothiazide (Diuril) ◦ Hydrochlorothiazide (HCTZ) {Esidrix, HydroDiuril} ◦ Polythiazide (Renese) ◦ Trichlomethiazide (Naqua, Metahydrin, Diurese) 16

 Thiazide-like drugs include ◦ Chlorthalidone (Hygroton) ◦ Indapamide (Lozol) ◦ Metolazone (Zaroxolyn) 17

 Drugs that affect the loop of Henle ◦ Bumetanide (Bumex) ◦ Ethacrynic acid (Edecrin) ◦ Furosemide (Lasix) ◦ Torsemide (Demadex) 18

 Act in the loop of Henle in the kidney ◦ Inhibits Na and Cl reabsorption  Some increase blood flow to glomeruli  Inhibits electrolyte absorption in proximal tubule ◦ Lose sodium, chloride, potassium, magnesium, sodium bicarbonate 19

 Onset of diuretic effect varies, but is within 1-2 hours. IV, drugs work within 5-10 minutes  Peak effect within 1-2 hours  Duration approximately 6 hours 20

 Maximum mg/day ◦ Bumex 10 mg per 24 hours ◦ Edecrin 400 mg per 24 hours ◦ Lasix 1000 mg/24 hours  Cross sensitivities ◦ Sulfonamides and Lasix, Demadex  SE to expect ◦ Oral irritation ◦ Dry mouth ◦ Orthostatic hypotension 21

 SE to report with loop diuretics ◦ GI irritation, abdominal pain ◦ Electrolyte imbalance, dehydration ◦ Hives, pruritus, rash ◦ Some can cause loss of hearing and hyperglycemia (interfere with hypoglycemic agents) 22

 Drug interactions ◦ Alcohol, barbiturates, narcotics ◦ Aminoglycosides ◦ Cisplatin ◦ NSAIDs ◦ Corticosteroids ◦ Probenecid ◦ Digoxin 23

 Loop diuretics include ◦ Bumetanide (Bumex) ◦ Ethacrynic acid (Edecrin) ◦ Furosemide (Lasix) ◦ Torsemide (Demadex) 24

 Why is there concern about the electrolyte balance? 25

 Weak antihypertensives  Mechanism of action unknown  Do work in distal renal tubule ◦ Retains potassium ◦ Excretes sodium ◦ Some have anti-aldosterone activity 26

 Maximum dosing per 24 hrs ◦ drug dependent  SE to expect with Midamor: ◦ anorexia, N/V, flatulence and HA  SE to report: ◦ electrolyte imbalance, dehydration, 27

 SE to expect and report with Aldactone and Dyrenium: ◦ mental confusion, HA, diarrhea, electrolyte imbalance, dehydration, gynecomastia, reduced libido, breast tenderness  Dyrenium can also cause allergic reaction (hives, pruritus, rash) 28

 Generally, drug interactions for the K+ sparing agents ◦ Lithium, ACE inhibitors, salt substitutes, K+ replacement ◦ NSAIDs,  Potassium-sparing drugs include ◦ Amiloride (Midamor) ◦ Spironolactone (Aldactone) ◦ Triamterene (Dyrenium) 29

 Potassium-sparing drugs include ◦ Amiloride (Midamor) ◦ Spironolactone (Aldactone) ◦ Triamterene (Dyrenium) 30

 Why is an adequate fluid intake important with diuretic therapy?  If the client has to get up during the night to void, what will they probably do? 31

 What are some good dietary sources of potassium?  If a client is on Aldactone, what would you tell them about high potassium foods? 32

 Assessments to make  Teaching to include: 33

 Drugs include ◦ Antibiotics  Fosfomycin (Monurol)  Quinolones : cinoxacin, nalidixic acid, norfloxacin  Methenamine madelate  Nitrofurantoin 34

 Fosfomycin (Monurol) ◦ Inhibits bacterial cell wall synthesis ◦ Reduces adherence of bacteria to epithelial cells of urinary tract ◦ Single dose therapy  SE to expect: ◦ nausea, diarrhea, abdominal cramps, flatulence  SE to report: ◦ perineal burning, dysuria  Indicates UTI is not responding to treatment  Drug interactions ◦ Drugs such as metoclopramide that increase GI motility 35

Norfloxacin (Noroxin) has wide range of activity against gram negative and gram positive bacteria  Expensive  Reserve for resistant/recurrent infections  SE to report ◦ Hematuria as crystals can form in urinary tract ◦ HA, tinnitus, dizziness, tingling sensations, photophobia  Various drug interactions can occur ◦ Assess client’s current drug therapy, monograph of quinolone being used 36

◦ Converts to ammonia and formaldehyde in acidic urine ◦ Used in clients susceptible to chronic, recurrent UTIs ◦ Preexisting infections treated with antibiotics  Implementation ◦ DO NOT crush the tablets ◦ pH testing of urine: report over 5.5  SE to expect ◦ N/V, belching  SE to report ◦ Hives, pruritus, rash ◦ Bladder irritation, dysuria, frequency  Drug interactions ◦ Acetazolamide, sodium bicarbonate ◦ Sulfamethizole 37

◦ Interferes with several bacterial enzyme systems ◦ Effective only in the urinary tract  SE to expect: ◦ N/V, anorexia, urine discoloration  SE to report: ◦ Dyspnea, chills, fever, erythematous rash, pruritus ◦ Peripheral neuropathies ◦ Second infection  Drug interactions ◦ Magnesium containing products can decrease absorption 38

 Bethanecole chloride (Urecholine)  Neostigmine (Prostigmin)  Oxybutynin chloride (Ditropan)  Phenazopyridine (Pyridium)  Tolterodine (Detrol) 39

◦ Parasympathetic nerve stimulant ◦ Causes contraction of detrusor urinae muscle  Results in urination  May also stimulate gastric motility  Can increase gastric tone  Can restore impaired rhythmic peristalsis  SE to expect ◦ Flushing of skin, HA  SE to report ◦ N/V, sweating, colicky pain, abdominal cramps ◦ Diarrhea, belching, involuntary defecation 40

◦ Anticholinesterase agent ◦ Binds to cholinesterase  Prevents destruction of acetylcholine  Effects are: miosis; increased tone of intestinal, skeletal, and bladder muscles  Bradycardia; stimulation of secretions of salivary and sweat glands  Constriction of bronchi and ureters  Neostigmine used to prevent and treat postoperative distension and urinary retention ◦ Assess for pregnancy, intestinal or urinary obstruction, peritonitis ◦ Assess coronary status 41

 Antispasmodic agent—acts directly on smooth muscle of the bladder ◦ Delays initial urge to void ◦ Do not use if glaucoma, myasthenia gravis, ulcerative colitis, obstructive uropathy  SE to expect ◦ Dry mouth, urinary hesitance, retention ◦ Constipation, bloating ◦ Blurred vision  Report any SE that are intensified 42

 Produces local anesthetic effect in urinary tract  Acts about 30 min. after administration  Used to relieve burning, pain, urgency, frequency in UTI  Reduces bladder spasms  SE to expect ◦ Reddish-orange urine color  SE to report ◦ Yellow sclera or skin 43

 Muscarinic receptor antagonists  Inhibit muscarinic action of acetylcholine on bladder smooth muscle  Used to treat overactive bladder  Do not use if glaucoma, ulcerative colitis, obstructive uropathy  S/E to expect ◦ Dry mouth ◦ Urinary hesitance, retention ◦ Constipation, bloating ◦ Blurred vision ◦ Report if the effects intensified 44

 Objective 18: Discuss patient education guidelines for drugs that affect the urinary system 45

 Objective 19: identify at least one nursing diagnosis that may be applicable for clients receiving diuretic therapy under the guidance of the instructor 46