CH 28: DIURETICS

Spironolactone

(Aldactone)- synthetic steroid that blocks aldosterone receptors. Tx: ascites, children w/ HF. Greatest antihypertensive activity. Adverse effect: hyperkalemia. DOSAGE: Adult 25-200 mg/day Onset of Action: 1-3 daysPeak Plasma Concentration/ Duration of Action: 2-3 days Available only in oral form. Pregnancy category D drug.

Acetazolamide

(Diamox) Available in both oral & parenteral forms. Pregnancy category C drug. DOSAGE: 250-500 mg/day Onset of Action: 1 hr Peak Plasma Concentration: 2-4 hr Duration of Action: 8-12 hr

Triamterene

(Dyrenium)- acts directly on distal renal tubule of the nephron to depress the resorption of Na & excretion of K & hydrogen. Little or no antihypertensive effect. DOSAGE: Adult 50-100 mg/day; *no more than 300 mg/day* Onset of Action: 2-3hr Peak Plasma Concentration: 6-8hr Duration of Action: 12-16hr Available only in oral form. Pregnancy category D drug.

Hydrochlorothiazide

(HydroDIURIL) Dosages exceeding 50 mg/day rarely produce additional clinical results and may only increase drug toxicity- AKA ceiling effect. DOSAGE: Adult 25-200 mg/day Older 12.5-25 mg/day Onset of Action: 2hr Peak Plasma Concentration: 4-6hr Duration of Action: 6-12hr Available only in oral form. Pregnancy category B drug.

Furosemide

(Lasix) Available in oral form- solution, tablets, & injectable. Pregnancy category C drug. DOSAGE (Adult): IM/IV 20-40 mg/dose PO 20-120 mg/day Onset of Action: IV 5min, PO 30-60min Peak Plasma Concentration: IV 15min, PO 1-2hr Duration of Action: IV 2 hr, PO 6-8hr

Amiloride

(Midamor) DOSAGE: Adult 5-20 mg/day Available only in oral form.

Metolazone

(Zaroxolyn)- more potent than the thiazide diuretics. Remains effective to a creatinine clearance as low as 10 mL/min. More efficacious when given 30 min before loop diuretics. DOSAGE: Adult 2.5-20 mg/day Onset of Action: 1hr Peak Plasma Concentration: 1-2hr Duration of Action: 24hr Available only in oral form. Pregnancy category B drug.

The primary health care provider instructs the nurse to administer a 20% solution of mannitol to a patient who has cerebral edema. What does the nurse recall before administering the drug to the patient? 1. To administer potassium supplements 2. To maintain normal room temperature 3. To store the drug in a brightly lit room 4. To give oral rehydration salts with the drug

2. To maintain normal room temperature Mannitol is an osmotic diuretic that is used in the treatment of cerebral edema that may occur due to head injuries. Mannitol is more likely to crystallize at low temperatures when its concentration exceeds 15%. Therefore, to avoid crystallization of the 20% solution of mannitol, the nurse should maintain normal room temperature before administering the drug. Because mannitol is an osmotic, diuretic potassium is not lost, and supplements are not needed. Exposure of mannitol to light can cause the chemicals in the medication to break down. The nurse should not administer oral rehydration salts to the patient, because they do not prevent the crystallization of mannitol.

Carbonic Anhydrase Inhibitors- ADVERSE EFFECTS

Metabolic acidosis Hypokalemia Melena Drowsiness, anorexia, paresthesias, hematuria, urticaria, photosensitivity

What is the correct pediatric dose of furosemide? 1. 1 to 2 mg/kg 2. 2 to 3 mg/kg 3. 3 to 4 mg/kg 4. 4 to 5 mg/kg

1. 1 to 2 mg/kg The pediatric dose of furosemide is 1 to 2 mg/kg of body weight. Doses of 2 to 3 mg/kg, 3 to 4 mg/kg, and 4 to 5 mg/kg are all considered too high for children. They may lead to disturbance in the normal electrolytic balance in the child.

A patient with acute pulmonary edema is receiving furosemide. What assessment finding indicates to the nurse that the intervention is working? 1. Lungs clear 2. Output 30 mL/hr 3. Improvement in mental status 4. Potassium level decreased from 4.5 to 3.5 mEq/L

1. Lungs clear Furosemide is a potent, rapid-acting diuretic that would be the drug of choice to treat acute pulmonary edema. Furosemide should not cause a drastic change in output or decrease in potassium level, and there is no evidence that it will create any change in mental status.

The nurse observes that a patient's vision is not improving after acetazolamide treatment. Which drug does the nurse anticipate will be prescribed for the patient for reducing intraocular pressure? 1. Mannitol 2. Amiloride 3. Furosemide 4. Spironolactone

1. Mannitol Acetazolamide is a carbonic anhydrase inhibitor (CAI) that is used in the treatment of open-angle glaucoma to reduce intraocular pressure. Mannitol can be used to reduce intraocular pressure in patients who are unresponsive to other drug therapies. Amiloride, furosemide, and spironolactone are not used for reducing intraocular pressure. Amiloride is a potassium-sparing diuretic that is used in the treatment of metabolic alkalosis and heart failure. Furosemide is a loop diuretic that is used in the treatment of pulmonary edema and the edema associated with heart failure, liver disease, nephrotic syndrome, and ascites. Spironolactone is a potassium-sparing diuretic that is used in the treatment of ascites related to liver cirrhosis.

What information will the nurse obtain prior to administering furosemide to a patient? Select all that apply. 1. The patient's allergies 2. The patient's serum potassium level 3. The patient's level of consciousness 4. The patient's baseline renal function 5. The patient's fluid intake and urine output

1. The patient's allergies 2. The patient's serum potassium level 4. The patient's baseline renal function 5. The patient's fluid intake and urine output The nurse should verify if the patient is allergic to sulfonamides, because there is a cross-allergy to loop diuretics. Before administering a loop diuretic such as furosemide to a patient, the nurse should assess the patient's serum potassium level. A major side effect of loop diuretics is hypokalemia. If the patient's potassium level is not within normal limits, the dose should not be given, and the primary health care provider should be notified. The nurse should also assess the patient's baseline renal function, because loop diuretics should not be administered to patients with end-stage renal disease, in which the nephrons are not functioning. The nurse should also assess the patient's fluid intake and urine output. A loop diuretic pulls off excess fluid, so if the output is greater than the intake, the medication is effective. The patient's level of consciousness would be assessed if an osmotic diuretic was administered for cerebral edema.

The nurse is assessing a patient who has been prescribed hydrochlorothiazide. What does the nurse inform the patient about the medication regimen? 1. "Take iron supplements every day." 2. "Take the dose only in the morning." 3. "You should limit your intake of oats." 4. "You should not eat melons or grapes."

2. "Take the dose only in the morning." Hydrochlorothiazide is a thiazide diuretic that is used in the treatment of various types of edema. Diuretics are to be taken in the morning because they cause urination at night (nocturia) and subsequent loss of sleep when taken late in the afternoon or night. Therefore, the nurse should instruct the patient to take the medication only in the morning to avoid the side effects of the drug. This medication does not cause anemia; therefore, the patient need not take iron supplements. The nurse can suggest that the patient eat fiber-rich food such as oats to help prevent constipation, but not because a diuretic is prescribed. Due to loss of fluids, the patient may have dehydration. Hence the nurse can suggest that the patient eat fruits high in fluid content such as melons and grapes.

What is the best information for the nurse to provide to a patient who is receiving spironolactone and furosemide therapy? 1. "This combination prevents dehydration and hypovolemia." 2. "This combination promotes diuresis but decreases the risk of hypokalemia." 3. "Moderate doses of two different diuretics are more effective than a large dose of one." 4. "Using two drugs increases the osmolality of plasma and the glomerular filtration rate."

2. "This combination promotes diuresis but decreases the risk of hypokalemia." Spironolactone is a potassium-sparing diuretic; furosemide causes potassium loss. Giving these together minimizes electrolyte imbalance. It is not accurate to state that the drug combination prevents dehydration and hypovolemia or that it increases the osmolality of plasma and the glomerular filtration rate. Stating that giving two different diuretics is more effective is not specific enough information for the patient.

What is the usual daily dose of spironolactone for an adult patient? 1. 10 to 50 mg/day 2. 25 to 200 mg/day 3. 100 to 300 mg/day 4. 300 to 400 mg/day

2. 25 to 200 mg/day The daily adult dose of spironolactone is 25 to 200 mg/day in a single dose or two divided doses. Giving 10 to 50 mg/day may not produce adequate therapeutic effects. A dose of 100 to 300 mg/day may be considered an overdose and may result in drug toxicity. A dose of 300 to 400 mg/day may be very toxic to the patient, causing severe fluid loss and hyperkalemia. Topics

How long after intravenous administration of furosemide does the nurse anticipate the beginning of diuresis? 1. 1 minute 2. 5 minutes 3. 30 minutes 4. 60 minutes

2. 5 minutes The effects of IV furosemide begin within 5 minutes of administration and last for 2 hours. IV therapy is used in critical situations (e.g., pulmonary edema) that demand immediate mobilization and elimination of fluid. If furosemide is applied by the oral route, the onset of action starts in 30 to 60 minutes. One minute is too little time to have any action of any drug.

The nurse questions the use of mannitol for which patient? 1. A 21-year-old head injury patient 2. A 47-year-old patient with anuria 3. A 67-year-old patient who ingested a poisonous substance 4. A 55-year-old patient receiving cisplatin to treat ovarian cancer

2. A 47-year-old patient with anuria Mannitol is not metabolized but is excreted unchanged by the kidneys. Potential water intoxication could occur if mannitol is given to a patient without urine output, which would impact renal function. Mannitol reduces cellular edema and increases urine production, causing diuresis. However, it produces only a slight loss of electrolytes, especially sodium. a Therefore, mannitol is not indicated for patients with peripheral edema, patients with head injuries, or patients who have ingested poisonous substances. Mannitol does not promote sufficient sodium excretion. It does not have any effect on patients taking antiprotozoals.

Which adjunct drug is useful in the long-term management of open-angle glaucoma? 1. Mannitol 2. Acetazolamide 3. Spironolactone 4. Hydrochlorothiazide

2. Acetazolamide Acetazolamide is the diuretic drug that is prescribed as adjunct therapy along with topical miotics for management of long-term glaucoma. Mannitol is an osmotic diuretic useful for vasodilation and for the treatment of edema. Spironolactone is useful in ascites associated with liver cirrhosis. Hydrochlorothiazide is useful for treating diabetes insipidus and hypertension. These drugs do not reduce intraocular pressure, because they do not affect the production or the outflow of aqueous humor.

Which physiologic change will be observed in a patient after administering diuretics? Select all that apply. 1. Increased plasma volume 2. Decreased cardiac output 3. Decreased blood pressure 4. Increased extracellular fluid volume 5. Increased peripheral vascular resistance

2. Decreased cardiac output 3. Decreased blood pressure Diuretics cause direct arterial dilation, which decreases cardiac output. The decreased cardiac output also decreases the blood pressure of the patient. Due to loss of sodium and water, there is a decrease in plasma volume and the extracellular fluid volume after administering diuretics. Due to direct arterial dilation, the peripheral vascular resistance decreases after administering diuretics.

A patient reveals that he or she is taking daily ibuprofen for chronic back pain. On reviewing the patient's medical history, the nurse learns that the patient is also taking furosemide for high blood pressure. What does the nurse anticipate that the primary health care provider will prescribe? 1. Decreased dose of ibuprofen 2. Increased dose of furosemide 3. Alternating doses of both medications 4. STAT venipuncture for serum calcium

2. Increased dose of furosemide When furosemide is used with nonsteroidal antiinflammatory drugs (NSAIDs), the diuretic activity of the drug is decreased due to the inhibition of the renal prostaglandins. The nurse can expect the primary health care provider to increase the dose of furosemide to have effective diuresis. Decreasing the dose of ibuprofen may not be effective in relieving the patient's pain. The primary health care provider does not alternate the doses of the two medications, because the patient will neither achieve effective pain relief nor receive the full effect of the diuretic. When furosemide is given with an NSAID, there is no impact on the serum calcium level.

Which class of diuretics is used to manage increased intracranial pressure? 1. Loop diuretics 2. Osmotic diuretics 3. Potassium-sparing diuretics 4. Carbonic anhydrase inhibitors

2. Osmotic diuretics Osmotic diuretics are useful for managing increased intracranial pressure. Loop diuretics cause rapid diuresis and are not effective for reducing intracranial pressure. Potassium-sparing diuretics act by inhibiting aldosterone. They are not helpful for managing intracranial pressure. Carbonic anhydrase inhibitors work mainly by inhibiting the carbonic anhydrase enzyme, in the proximal tubule of the nephron. They don't have any effect on intracranial pressure.

A patient asks the nurse about taking potassium supplements while taking triamterene. What is the nurse's best response? 1. "I will call your health care provider to discuss your concerns." 2. "You are correct about potassium. I will make sure that you get some right away." 3. "You are on a diuretic that is potassium-sparing, so there is no need for extra potassium." 4. "Your potassium level was normal in this morning's laboratory report, so no supplement is needed."

3. "You are on a diuretic that is potassium-sparing, so there is no need for extra potassium." Triamterene is a potassium-sparing diuretic. It causes sodium and water to be excreted while potassium is retained. It inhibits both aldosterone-induced and basal sodium reabsorption. Patients undergoing triamterene therapy neither need to discuss potassium supplements with the health care provider nor need potassium supplements. Monitoring the patient's potassium level is important, but for potassium-sparing diuretics, potassium supplements are not required.

A patient is taking hydrochlorothiazide. On assessment, the nurse notices the patient has muscle weakness and hypotension. What is the nurse's first intervention? 1. Reduce salt in the patient's food 2. Administer calcium supplements 3. Assess the serum potassium level 4. Give a lower dose of the medication

3. Assess the serum potassium level Hydrochlorothiazide overdose leads to hypokalemic symptoms, which are characterized by muscle weakness and hypotension. The nurse should immediately assess the patient's serum potassium level to determine the course of action. Decreasing the salt intake would further reduce the patient's blood pressure and cause sodium deficiency. Giving calcium supplements alone does not reduce the symptoms caused by potassium deficiency. Reducing the dose of the medication will not help restore the electrolyte balance.

Osmotic- NURSING IMPLICATIONS

Monitor for crystallization in vial of mannitol before admin. May crystallize at cooler temps; more likely for concentrations above 15%. Monitor & assess for renal function, PE, & active intracranial bleeding.

A patient with hypertension is receiving spironolactone therapy. The nurse notices that the patient's serum potassium level is 6.2 mEq/L. What does the nurse anticipate will be prescribed for the patient? 1. Mannitol 2. Amiloride 3. Furosemide 4. Acetazolamide

3. Furosemide The patient has been diagnosed with hyperkalemia, or elevated serum potassium. This contraindicates spironolactone, because it is a potassium-sparing diuretic and will worsen the hyperkalemia. The primary health care provider should prescribe a loop diuretic such as furosemide, which eliminates potassium. Mannitol is an osmotic diuretic, which does not show any significant effect on the patient's potassium levels. Amiloride is a potassium-sparing diuretic that when administered may cause a further increase in the serum potassium levels. Acetazolamide is a carbonic anhydrase inhibitor, which does not help eliminate potassium.

The nurse is assessing a patient who has been prescribed diuretics. On reviewing the patient's laboratory reports, the nurse finds that the patient's creatinine clearance rate is 20 mL/min. What dosage regimen does the nurse expect the provider to order? 1. Hydrochlorothiazide 5 mg/kg/day by mouth in a single dose 2. Hydrochlorothiazide 10 mg/kg/day intravenous in divided doses 3. Furosemide 5 mg/kg/day by mouth in the morning in a single dose 4. Furosemide 7 mg/kg/day via the intravenous route in two divided doses

3. Furosemide 5 mg/kg/day by mouth in the morning in a single dose The creatinine clearance rate helps determine renal function. A creatinine clearance rate of 120 mL/min is indicative of normal kidney function. A creatinine clearance as low as 20 mL/min indicates that the patient has impaired renal function. Furosemide can be prescribed to patients who have impaired renal function and a creatinine clearance of 20 mL/min. Due to its potent activity, it is administered at a dose of 5 mg/kg/day in a single dose. Hydrochlorothiazide in any amount is contraindicated in patients whose creatinine levels are less than 30 mL/min. Therefore, hydrochlorothiazide should not be prescribed for the patient. Furosemide should not exceed 6 mg/kg/day.

Which drug can be prescribed for the treatment of idiopathic hypercalciuria? 1. Mannitol 2. Amiloride 3. Metolazone 4. Furosemide

3. Metolazone Thiazide diuretics are used to treat idiopathic hypercalciuria. Metolazone is a thiazide diuretic drug that is useful in the treatment of idiopathic hypercalciuria. Mannitol, amiloride, and furosemide are not used to treat idiopathic hypercalciuria. Mannitol is an osmotic diuretic that is used for the treatment of cerebral edema and acute renal failure. Amiloride is a potassium-sparing diuretic that is used in the management of heart failure and metabolic alkalosis. Furosemide is a loop diuretic that is used in the treatment of pulmonary edema and the edema associated with heart failure, liver disease, nephrotic syndrome, and ascites.

Which intervention does the nurse incorporate while caring for a patient who experiences furosemide toxicity? 1. Administer deferoxamine 2. Administer activated charcoal 3. Replace the fluids and the electrolytes 4. Replace the indwelling urinary catheter

3. Replace the fluids and the electrolytes Furosemide is a loop diuretic, which causes fluid and electrolyte imbalances from toxicity. Therefore, the nurse should administer intravenous fluid and electrolytes to replace the fluids and to maintain the electrolyte balance in the patient. Deferoxamine mesylate is used for preventing iron toxicity, but not furosemide toxicity. Activated charcoal is an antidote used for treating many chemical poisonings, but it is not effective in reducing the effects of furosemide toxicity. Replacing the indwelling urinary catheter regularly may increase the risk of infections but does not reduce the effects of furosemide toxicity.

An elderly patient who has hypertension has been prescribed furosemide. The nurse advises the patient to take the medication in the morning. What rationale does the nurse give the patient? 1. To prevent fluid and electrolyte imbalances 2. To prevent orthostatic hypotension changes 3. To prevent the patient from urinating at night 4. To prevent an increase in overall body weight

3. To prevent the patient from urinating at night Furosemide causes nocturia (urinating during the night). This may cause sleep disturbances in the patient. Therefore, to prevent nocturia and promote sleep, the nurse instructs the patient to take the medication in the morning. Fluid and electrolyte imbalances and orthostatic hypotension are the side effects of furosemide. The nurse would administer intravenous fluids to prevent electrolyte imbalances. The nurse would instruct the patient to change positions slowly to prevent orthostatic hypotension. Furosemide usually reduces the body weight, so taking the drug in the morning would not have any effect on body weight.

7. The order reads: Give mannitol 0.5 g/kg IV now, over 2 hours. The patient weighs 165 lb, and you have a 100-mL vial of 20% mannitol. How many grams will the patient receive?

37.5 g

A 10-year-old child who has congestive heart failure has been prescribed furosemide. Which instruction does the nurse give to the child's parents to prevent adverse effects of the medication? 1. "Administer the medication on an empty stomach." 2. "Do not give oral rehydration drinks to your child." 3. "Give the medication to your child before bedtime." 4. "Protect your child from excessive sunlight exposure."

4. "Protect your child from excessive sunlight exposure." The parents should be instructed to prevent the child from being exposed to sunlight. Exposure to excessive sunlight may cause loss of fluids and electrolytes in the child and result in dehydration. Furosemide should be given with meals or with milk to prevent gastrointestinal irritation. Therefore, the nurse should not instruct the parents to give the medication on an empty stomach. Oral rehydration supplements may be given in case of excessive loss of fluids. The diuretic medication needs to be taken early in the morning with food or milk at the same time every day. Medication at night causes nocturia in the child.

At which concentration is the intravenous injection of mannitol most likely to crystallize? 1. 5% 2. 10% 3. 15% 4. 20%

4. 20% Mannitol may crystallize when exposed to low temperatures. This is more likely to occur when concentrations exceed 15%.

Which drug may cause melena as a side effect? 1. Mannitol 2. Furosemide 3. Metolazone 4. Acetazolamide

4. Acetazolamide Melena and photosensitivity are the adverse effects of acetazolamide. Mannitol causes thrombophlebitis, convulsions, and pulmonary congestion. Furosemide doesn't cause melena as an adverse effect. Photosensitivity and thrombocytopenia are adverse effects of thiazide and thiazide-like diuretics such as metolazone.

What acts to increase the reabsorption of water? 1. Aldosterone 2. Hypernatremia 3. Glomerular filtration 4. Antidiuretic hormone

4. Antidiuretic hormone Antidiuretic hormone (ADH), known as the water-conserving hormone, acts on the collecting duct to regulate conservation of water by increasing the water permeability of the collecting ducts; this increases the amount of water reabsorbed into the bloodstream. Aldosterone is a mineralocorticoid steroid hormone produced by the adrenal cortex that regulates sodium and water balance. Hypernatremia is a condition in which an abnormally high sodium concentration is present in the blood. It may be due to defective renal excretion but is more commonly caused by excessive dietary sodium or replacement therapy. Glomerular filtration is the first step in urine formation. It removes solutes and water from the arterial blood; hence glomerular filtrate is not diluted.

The nurse is caring for a patient who is receiving digoxin and acetazolamide therapy. Which action by the nurse is necessary to prevent adverse effects? 1. Assess the patient's heart rate frequently. 2. Assess the patient's skin for any signs of peeling. 3. Check the patient's platelet levels in the blood reports. 4. Check the patient's potassium levels in the lab reports.

4. Check the patient's potassium levels in the lab reports. The patient is on a combination therapy of digoxin and acetazolamide. Acetazolamide is a carbonic anhydrase inhibitor (CAI) that causes hypokalemia (reduced potassium levels). This will increase digoxin toxicity in the patient. Therefore, the nurse must assess the serum levels of potassium in the patient's blood chemistry reports to detect hypokalemia. The nurse would assess the patient's heart rate more frequently for signs of tachycardia if the patient were receiving an osmotic diuretic, but this adverse effect is not associated with CAIs. Shedding of the skin is called exfoliative dermatitis and is the adverse effect of loop diuretics, not CAIs. The platelet levels decrease in the body (thrombocytopenia) with the use of torsemide, which is a loop diuretic, so this assessment would not be useful for a patient on a CAI.

Which laboratory value will the nurse report to the health care provider as a potential adverse response to hydrochlorothiazide? 1. Calcium level of 9 mg/dL 2. Sodium level of 140 mEq/L 3. Chloride level of 100 mEq/L 4. Fasting blood glucose level of 140 mg/dL

4. Fasting blood glucose level of 140 mg/dL Hydrochlorothiazide can cause hyperglycemia; normal fasting blood glucose should be 60 to 110 mg/dL. Normal calcium level is approximately 8.8 to 10.3 mg/dL, normal sodium level is 135 to 147 mEq/L, and normal chloride level is 95 to 107 mEq/L.

Loop- INDICATIONS

Rapid action Potent for use, *when thiazides fail* Cause volume depetion

Loop- INTERACTIONS

Aminoglycosides, vancomycin- additive. Increased neurotoxicity, esp. ototoxicity. Corticosteroids, digoxin- hypokalemia. Additive hypokalemia, increased digoxin toxicity. Lithium- decreased renal excretion. Decreased diuretic activity. NSAIDs- renal prostaglandin inhibition. Decreased diuretic activity. Antidiabetics- antagonism. Decreased effectiveness of antidiabetics (hyperglycemia).

Potassium-sparing- INTERACTIONS

ACE inhibitors, K supplements- hyperkalemia. Lithium- lithium toxicity. NSAIDs- inhibit renal prostaglandins. Diminished diuretic response.

Loop- NURSING IMPLICATIONS

Rapid volume/ electrolyte depletion (Same as for thiazides)

Carbonic Anhydrase Inhibitors- DRUGS

Acetazolamide

Potassium-sparing- DRUGS

Spironolactone Amiloride Triamterene Eplerenone

Thiazides- INTERACTIONS

Antidiabetics- antagonism. Reduce therapeutic hypoglycemic effects. Corticosteroids- additive. Hypokalemia. Digoxin- hypokalemia. Increased digoxin toxicity. Lithium- decreased clearance. Increased lithium toxicity. NSAIDs- inhibition of renal prostaglandins. Decreased diuretic effect.

Mannitol

Available only in parenteral form- 5%, 10%, 15%, 20%, 25% solutions for IV push. Pregnancy category C drug. DOSAGE: *Dose varies widely depending on indication* Onset of Action: 0.5-1 hr Peak Plasma Concentration: 0.25-2 hr Duration of Action: 6-8 hr

Loop- MOA

Block Cl & (secondarily) Na reabsorption at loop of Henle. Activate renal prostaglandins, dilating blood vessels all over, especially kidneys & lungs- reduce preload & CVP.

Combo Thiazide & Potassium-Sparing- NURSING IMPLICATIONS

Caution client previously on loop or thiazide not to overdo K-rich foods because of K-sparing component in new drug. Follow scheduling doses to avoid sleep disruption.

Thiazides- DRUGS

Chlorthalidone Hydrochlorothiazide Indapamide Metolazone

Potassium-sparing (Spironolactone)- MOA

Competitively binds to aldosterone receptors in collecting ducts & distal convoluted tubules, blocking reabsorption of Na & H2O.

Osmotic- ADVERSE EFFECTS

F/E imbalance PE from rapid fluid shifts Tachycardia from rapid fluid loss Hyponatremia & dehydrations N/V, HA

Loop- CONTRAINDICATIONS

Hepatic coma Severe electrolyte loss Sulfonamide allergy

Thiazides- CONTRAINDICATIONS

Hepatic coma (metolazone) Anuria Severe renal failure

Thiazides- INDICATIONS

Decrease fluid volume Increase excretion of water, Na, K, & Cl Severe HTN Enhances o/ antihypertensives Inexpensive, effective (orally)

Combo Thiazide & Potassium-Sparing- INDICATIONS

Decreases fluid volume while minimizing K loss

Carbonic Anhydrase Inhibitors- MOA

Inhibit activity of carbonic anhydrase enzyme system along nephron in proximal tubule. Little Na & H2O is reabsorbed, & is instead is eliminated in urine.

Carbonic Anhydrase Inhibitors- INTERACTIONS

Digoxin- hypokalemia. Increased risk of digoxin toxicity. Corticosteroids- hypokalemia. Amphetamines, carbamazepine, cyclosporine, phenytoin, quinidine- additive.

Thiazides- MOA

Inhibit reabsorption of Na, K, & Cl in distal convoluted tubule, resulting in osmotic water loss. Vasodilates arterioles, reducing PVR, preoload, & afterload.

Loop- DRUGS

Furosemide Torsemide Bumetadine

Combo Thiazide & Potassium-Sparing- DRUGS

HCTZ & Triamterene HCTZ + Amiloride HCTZ + Spironolactone

Potassium-sparing- ADVERSE EFFECTS

Hyperkalemia Gynecomastia Sexual dysfunction

Potassium-sparing- CONTRAINDICATIONS

Hyperkalemia Severe renal failure Anuria Triamterene- hepatic failure

Loop- ADVERSE REACTIONS

Hypokalemia Hyperuricemia Glucose intolerance Hypercholesterolemia Hypertriglyceridemia Sexual dysfunction Weakness

Thiazides- ADVERSE REACTIONS

Hypokalemia Sx: dry mouth, thirst, weakness, drowsiness, lethargy, muschle aches, tachycardia Hyperuricemia Glucose intolerance Hypercholesterolemia Sexual dysfunction

Carbonic Anhydrase Inhibitors- CONTRAINDICATIONS

Hyponatremia Hypokalemia Severe renal/ hepatic dysfunction Adrenal gland insufficiency Cirrhosis

Osmotic- MOA

Increases osmotic pressure in glomerular filtrate in nephron, esp. proximal tubule & descending limp of loop of Henle. Pulls water into renal tubules from surrounding tissues, inhibiting tubular reabsorption of water & solutes, producing rapid diuresis. Induces vasodilation by increasing glomerular filtration & renal plasma flow.

Carbonic Anhydrase Inhibitors- NURSING IMPLICATIONS

Increases risk of digitalis toxicity. Increases risk of hypokalemia in clients taking corticosteroids. Monitor serum K/ Na levels. Assess for liver/ renal function, acidosis.

Osmotic- DRUGS

Mannitol

Thiazides- NURSING IMPLICATIONS

Observe for postural hypotension; can be potentiated by: ETOH, barbiturates, narcotics Caution w/: renal failure, gout, client taking lithium Hypokalemia increases risk for digitalis toxicity. Admin K supplements. Encourage intake of K-rich foods.

Osmotic- INDICATIONS

Oliguria Prevention of kidnesy failure Decrease ICP in Pts w/ narrow-anlge glaucoma

Carbonic Anhydrase Inhibitors- INDICATIONS

Open-angle glaucoma, *when topical miotic drugs or epinephrine derivatives fail.* Edema secondary to HF, *that is resistant to o/ diuretics.* High-altitude sickness

Osmotic- CONTRAINDICATIONS

Severe renal disease PE Active intracranial bleeding

Combo Thiazide & Potassium-Sparing- ADVERSE EFFECTS

Side effects of individual drug offset or minimized by its partner

Potassium-sparing- INDICATIONS

Volume depletion w/o significant K loss

Potassium-sparing- NURSING IMPLICATIONS

Watch for hyperkalemia & renal failure in those treated w/ ACE inhibitors or NSAIDs. Watch for increase in serum lithium levels. Give after meals to decrease GI distress.

6. An older adult patient has been discharged following treatment for a mild case of heart failure. He will be taking a loop diuretic. Which instruction(s) from the nurse are appropriate? (Select all that apply.) a. "Take the diuretic at the same time each morning." b. "Take the diuretic only if you notice swelling in your feet." c. "Be sure to stand up slowly because the medicine may make you feel dizzy if you stand up quickly." d. "Drink at least 8 glasses of water each day." e. "Here is a list of foods that are high in potassium; you need to avoid these." f. "Please call your doctor immediately if you notice muscle weakness or increased dizziness."

a. "Take the diuretic at the same time each morning." c. "Be sure to stand up slowly because the medicine may make you feel dizzy if you stand up quickly." f. "Please call your doctor immediately if you notice muscle weakness or increased dizziness."

2. When monitoring laboratory test results for patients receiving loop and thiazide diuretics, the nurse knows to look for a. decreased serum levels of potassium. b. increased serum levels of calcium. c. decreased serum levels of glucose. d. increased serum levels of sodium.

a. decreased serum levels of potassium.

4. Which statement needs to be included when the nurse provides patient education for a patient with heart failure who is taking daily doses of spironolactone (Aldactone)? a. "Be sure to eat foods that are high in potassium." b. "Avoid foods that are high in potassium." c. "Avoid grapefruit juice while taking this medication." d. "A low-fiber diet will help prevent adverse effects of this medication."

b. "Avoid foods that are high in potassium."

8. A patient is taking an aminoglycoside antibiotic for pneumonia, and will also be taking the loop diuretic furosemide (Lasix) due to fluid overload. The nurse will monitor carefully for which potential effect from the interaction of these two drugs? a. Nephrotoxicity b. Ototoxicity c. Pulmonary fibrosis d. Hepatotoxicity

b. Ototoxicity

3. When the nurse is checking the laboratory data for a patient taking spironolactone (Aldactone), which result would be a potential concern? a. Serum sodium level of 140 mEq/L b. Serum calcium level of 10.2 mg/dL c. Serum potassium level of 5.8 mEq/L d. Serum magnesium level of 2.0 mg/dL

c. Serum potassium level of 5.8 mEq/L

5. A patient with diabetes has a new prescription for a thiazide diuretic. Which statement will the nurse include when teaching the patient about the thiazide drug? a. "There is nothing for you to be concerned about when you are taking the thiazide diuretic." b. "Be sure to avoid foods that are high in potassium." c. "You need to take the thiazide at night to avoid interactions with the diabetes medicine." d. "Monitor your blood glucose level closely, because the thiazide diuretic may cause the levels to increase."

d. "Monitor your blood glucose level closely, because the thiazide diuretic may cause the levels to increase."

1. The nurse is reviewing the medications that have been ordered for a patient for whom a loop diuretic has just been prescribed. The loop diuretic may have a possible interaction with which of the following? a. Vitamin D b. warfarin c. Penicillins d. NSAIDs

d. NSAIDs