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NURS 1950: Pharmacology
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 Objective 1: list two (2) major physiological
functions of the kidneys
 Objective 2: list the four (4) processes
carried out by the nephron
 Objective 3: name the part of the nephron
responsible for each of the processes
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 Objective 4: name the pituitary hormone that
influences the urine volume
 Objective 5: name the adrenocortical
hormone that influences the urine volume
 Objective 6: list the four (4) ways in which
fluid is normally lost from the body
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 Objective 7: describe the actions of diuretics
Diuretics act to
Deplete
blood volume
Excrete
sodium
Vasodilate
peripheral arterioles
(how is unknown)
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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
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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)
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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
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◦ Diamox very weak diuretic
 Useful in treating glaucoma
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◦ Aminophylline
◦ Theophylline
◦ Caffeine
◦ Theobromine
 Diuretic effect from improved blood
flow to kidney
 Generally not used for diuretic
effect
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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
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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
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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
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 Thiazides
can interact with
◦ Digoxin, corticosteroids
◦ Lithium, NSAIDs
◦ Oral hypoglycemic agents
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
Thiazide diuretics include
◦ Bendroflumethiazide (Naturetin)
◦ Chlorothiazide (Diuril)
◦ Hydrochlorothiazide (HCTZ) {Esidrix,
HydroDiuril}
◦ Polythiazide (Renese)
◦ Trichlomethiazide (Naqua,
Metahydrin, Diurese)
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 Thiazide-like
drugs include
◦Chlorthalidone (Hygroton)
◦Indapamide (Lozol)
◦Metolazone (Zaroxolyn)
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 Drugs
that affect the loop of
Henle
◦ Bumetanide (Bumex)
◦ Ethacrynic acid (Edecrin)
◦ Furosemide (Lasix)
◦ Torsemide (Demadex)
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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

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 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
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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
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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)
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Drug interactions
◦ Alcohol, barbiturates, narcotics
◦ Aminoglycosides
◦ Cisplatin
◦ NSAIDs
◦ Corticosteroids
◦ Probenecid
◦ Digoxin
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Loop diuretics include
◦ Bumetanide (Bumex)
◦ Ethacrynic acid (Edecrin)
◦ Furosemide (Lasix)
◦ Torsemide (Demadex)
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 Why
is there concern about the
electrolyte balance?
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Weak antihypertensives
 Mechanism of action unknown
 Do work in distal renal tubule
◦ Retains potassium
◦ Excretes sodium
◦ Some have anti-aldosterone activity
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Maximum dosing per 24 hrs
◦ drug dependent
 SE to expect with Midamor:
◦ anorexia, N/V, flatulence and HA
 SE to report:
◦ electrolyte imbalance, dehydration,
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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)
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
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)
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 Potassium-sparing
drugs include
◦ Amiloride (Midamor)
◦ Spironolactone (Aldactone)
◦ Triamterene (Dyrenium)
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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?
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What are some good dietary sources of
potassium?
If a client is on Aldactone, what would you tell
them about high potassium foods?
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Assessments to make
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Teaching to include:
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Drugs include
◦ Antibiotics
 Fosfomycin (Monurol)
 Quinolones : cinoxacin, nalidixic
acid, norfloxacin
 Methenamine madelate
 Nitrofurantoin
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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
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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
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◦ Converts to ammonia and formaldehyde in acidic urine
◦ Used in clients susceptible to chronic, recurrent UTIs
◦ Preexisting infections treated with antibiotics
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Implementation
◦ DO NOT crush the tablets
◦ pH testing of urine: report over 5.5
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SE to expect
◦ N/V, belching

SE to report
◦ Hives, pruritus, rash
◦ Bladder irritation, dysuria, frequency
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Drug interactions
◦ Acetazolamide, sodium bicarbonate
◦ Sulfamethizole
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◦ Interferes with several bacterial enzyme systems
◦ Effective only in the urinary tract
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SE to expect:
◦ N/V, anorexia, urine discoloration
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SE to report:
◦ Dyspnea, chills, fever, erythematous rash, pruritus
◦ Peripheral neuropathies
◦ Second infection
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Drug interactions
◦ Magnesium containing products can decrease
absorption
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Bethanecole chloride (Urecholine)
 Neostigmine (Prostigmin)
 Oxybutynin chloride (Ditropan)
 Phenazopyridine (Pyridium)
 Tolterodine (Detrol)
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◦ 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
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◦ 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
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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
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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
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SE to expect
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◦ Reddish-orange urine color

SE to report
◦ Yellow sclera or skin
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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
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Dry mouth
Urinary hesitance, retention
Constipation, bloating
Blurred vision
Report if the effects intensified
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
Objective 18: Discuss patient
education guidelines for drugs that
affect the urinary system
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Objective 19: identify at least one nursing
diagnosis that may be applicable for clients
receiving diuretic therapy under the guidance
of the instructor
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