Transcript Body System Adverse Effects

Diuretics
Lilley Reading & Workbook, Chap 25
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Drugs that accelerate the rate of urine formation
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In the nephron, where sodium goes, water follows
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◦ 20% to 25% of all sodium is reabsorbed into the
bloodstream in the ascending loop of Henle
◦ 5% to 10% in the distal convoluted tubules
◦ 3% in collecting ducts
If water is not absorbed, it is excreted as urine
Result: removal of sodium and water
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Carbonic anhydrase inhibitors
Loop diuretics
Osmotic diuretics
Potassium-sparing diuretics
Thiazide and thiazide-like diuretics
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The enzyme carbonic anhydrase helps to make H+ ions available for
exchange with sodium and water in the proximal tubules
CAIs
◦ block the action of carbonic anhydrase,
◦ thus preventing the exchange of H+ ions with sodium and water
◦ reduces H+ ion concentration in renal tubules
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Result:
◦ increased excretion of bicarbonate, sodium, water, & K+
◦ Resorption of water is decreased and urine volume is increased
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acetazolamide (Diamox)
methazolamide
dichlorphenamide
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Adjunct drugs in the long-term management of open-angle
glaucoma*
Used with miotics to lower intraocular pressure before ocular surgery
in certain cases
Also useful in the treatment of:
◦ Edema*
◦ Epilepsy
◦ High-altitude sickness
Acetazolamide (Diamox) is used in the management of edema
secondary to HF when other diuretics are not effective*
CAIs are less potent diuretics than loop diuretics or thiazides—the
metabolic acidosis they induce reduces their diuretic effect in 2-4
days
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Metabolic acidosis
Anorexia
Hematuria
Photosensitivity
Melena
Hypokalemia
 Drowsiness
 Paresthesias
 Urticaria
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Act directly on the ascending limb of the loop of
Henle to inhibit chloride and sodium resorption
Increase renal prostaglandins, resulting in the
dilation of blood vessels and reduced peripheral
vascular resistance
bumetanide (Bumex)
ethacrynic acid (Edecrin)
furosemide (Lasix)
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Potent diuresis and subsequent loss of fluid
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Decreased fluid volume causes:
◦ Reduced BP
◦ Reduced pulmonary vascular resistance
◦ Reduced systemic vascular resistance
◦ Reduced central venous pressure
◦ Reduced left ventricular end-diastolic pressure
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Potassium and sodium depletion
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Edema associated with HF or hepatic
or renal disease
Control of hypertension
Increase renal excretion of calcium in patients
with hypercalcemia
Certain cases of HF resulting from diastolic
dysfunction
Body System
Adverse Effects
CNS
Dizziness, headache,
tinnitus, blurred vision
GI
Nausea, vomiting,
diarrhea
Agranulocytosis,
neutropenia,
thrombocytopenia
Hematologic
Metabolic
Hypokalemia,
hyperglycemia,
hyperuric
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Work mostly in the proximal tubule
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Nonabsorbable, producing an osmotic effect
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Pull water into renal tubules from the surrounding tissues
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Inhibits tubular resorption of water and solutes
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Increases glomerular filtration and renal plasma
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Reduces excessive intraocular pressure
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Used in the treatment of patients in the early,
oliguric phase of ARF
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To promote the excretion of toxic substances
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Reduction of intracranial pressure
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Treatment of cerebral edema
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NOT indicated for peripheral edema
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Convulsions
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Thrombophlebitis
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Pulmonary congestion
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Also headaches, chest pains, tachycardia,
blurred vision, chills, and fever
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mannitol (Osmitrol)
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Intravenous infusion only
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May crystallize when exposed to low
temperatures—use of a filter is required
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Interfere with sodium-potassium exchange in collecting
ducts and convoluted tubules
Competitively bind to aldosterone receptors
◦ Block the resorption of sodium and water
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Prevent potassium from being pumped into the tubule,
thus preventing its secretion
Competitively block the aldosterone receptors and inhibit
its action
Sodium and water are excreted
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amiloride (Midamor)
spironolactone (Aldactone)
triamterene (Dyrenium)
Also known as aldosterone-inhibiting diuretics
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spironolactone and triamterene
◦ Hyperaldosteronism
◦ Hypertension
◦ Reversing the potassium loss caused by potassium-losing
drugs
◦ Certain cases of heart failure
◦ Liver failure
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Amiloride
◦ Treatment of HF
Body System
Adverse Effects
CNS
Dizziness, headache
GI
Cramps, nausea,
vomiting, diarrhea
Other
Urinary frequency,
weakness
**hyperkalemia**
Spironolactone
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Gynecomastia
Amenorrhea
Irregular menses
Postmenopausal bleeding
Actions:
 Acts in the distal convoluted tubule
◦ Inhibit tubular resorption of sodium, chloride, and potassium ions
◦ Result: water, sodium, and chloride are excreted
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Potassium is also excreted to a lesser extent
Dilate the arterioles by direct relaxation
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Results:
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◦ Lowered peripheral vascular resistance
◦ Sodium, water, chloride and potassium are excreted
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Thiazide diuretics
◦ hydrochlorothiazide (Esidrix, HydroDIURIL)
◦ chlorothiazide (Diuril)
◦ trichlormethiazide (Metahydrin)
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Thiazide-like diuretics
◦ chlorthalidone (Hygroton)
◦ metolazone (Mykrox, Zaroxolyn)
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Thiazides should not be used if creatinine
clearance is less than 30 to 50 mL/min
(normal is 125 mL/min)
Metolazone (Zaroloxyn) remains effective
to a creatinine clearance of 10 mL/min
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Hypertension – first line drug for HTN
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Edematous states
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Idiopathic hypercalciuria
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Diabetes insipidus
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Heart failure due to diastolic dysfunction
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Adjunct drugs in treatment of edema related to HF,
hepatic cirrhosis, corticosteroid therapy
Body System
Adverse Effects
CNS
Dizziness, headache, blurred vision,
paresthesias, decreased libido
GI
Anorexia, nausea,
vomiting, diarrhea
GU
Impotence
Integumentary
Urticaria, photosensitivity
Metabolic
Hypokalemia, glycosuria, hyperglycemia,
hyperuricemia
OTHER EFFECTS ALSO
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Thorough patient history and physical examination
Assess baseline fluid volume status, intake and output,
serum electrolyte values, weight, and vital signs—
especially postural BPs/orthostatic BPs
Assess for disorders that may contraindicate or
necessitate cautious use of these drugs
Monitor serum K+ levels during therapy
◦ K+ supplements are usually recommended to maintain K+ levels
at approximately 4 mEq/L
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Instruct patients to take in the morning as much as
possible to avoid interference with sleep patterns
Teach patients to maintain proper nutritional and fluid
volume status
Teach patients to eat more potassium-rich foods when
taking any but the potassium-sparing drugs
Foods high in potassium include bananas, oranges,
dates, raisins, plums, fresh vegetables, potatoes, meat,
and fish, apricots, whole grain cereals, legumes
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Patients taking diuretics along with a digitalis preparation
digoxin (Lanoxin) should be taught to monitor for
digitalis toxicity
Diabetic patients who are taking thiazide and/or loop
diuretics should be told to monitor blood glucose and
watch for elevated levels
Change positions slowly, and to rise slowly after sitting
or lying to prevent dizziness and possible fainting related
to orthostatic hypotension
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Encourage patients to keep a log of their daily weight
A weight gain of 2 or more pounds a day or 5 or more
pounds a week should be reported immediately
Encourage patients to return for follow-up visits and
labwork
Notify physician if you are ill with nausea, vomiting,
and/or diarrhea because fluid loss may be dangerous
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Excessive consumption of licorice can lead to an
additive hypokalemia in patients taking thiazides
Signs and symptoms of hypokalemia include muscle
weakness, constipation, irregular pulse rate, and
overall feeling of lethargy
Notify the physician immediately if rapid heart rate or
syncope occurs (reflects hypotension or fluid loss)
Diuretics are used for which of the following
reasons? (Select all that apply.)
1. treat hypertension
2. treat edema with heart failure
3. increase urine fl ow
4. treat hyperuricemia (increased uric
acid level)
Potassium-sparing diuretics are administered
in combination with other types
of diuretics to do which of the following?
(Select all that apply.)
1. treat hypertension
2. treat heart failure
3. prevent hypokalemia
4. prevent hyperkalemia
The most potent class of diuretics currently
available is:
1. thiazide-type.
2. potassium-sparing type.
3. loop-type.
4. carbonic anhydrase inhibitor.
Patients with diabetes mellitus receiving a
diuretic should be observed for:
1. hypoglycemia.
2. hyperglycemia.
3. hyperkalemia.
4. normonatremia.