Drugs Used for Diuresis Chapter 29 Drugs Used for Diuresis Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Chapter 29 Lesson 29.1 Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Objectives Identify the action of diuretics Describe the goal of administering diuretics to treat hypertension, heart failure, or increased intraocular pressure or before vascular surgery in the brain Identify the effects of diuretics on blood pressure, electrolytes, and diabetic or prediabetic patients Review possible underlying pathologic conditions that may contribute to the development of excess fluid volume in the body Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Diuretics Used to increase flow of urine to reduce excess water in the body Primarily used to treat heart failure, hypertension Other uses: liver disease, renal disease, cerebral edema, increased intraocular pressure, treat hypercalcemia Therapeutic outcomes: reduce edema, improve symptoms of excess fluid After lifestyle modifications, diuretics (often in addition to other antihypertensives) may be used as primary agents to treat hypertension. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Pathologic Conditions Contributing to Excess Fluid Heart failure Edema, adventitious lung sounds, dyspnea, change in mental status Liver disease Jaundice, ascites, disorientation, history of alcohol dependence, overdose of OTC medications Adverse outcomes if diuretics not given: renal failure, pulmonary congestion, edema, hypertension, stroke, death Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Sites of Action in the Nephron Diuretics act on the kidneys to decrease reabsorption of sodium, chloride, and water. The distal tubules is the site of action for thiazide and potassium-sparing drugs. The loop of Henle is the site of action for loop-diuretics. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Chapter 29 Lesson 29.2 Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Objectives Cite nursing assessments used to evaluate renal function Cite nursing assessments used to evaluate a patient’s state of hydration State which electrolytes may be altered by diuretic therapy Review the signs and symptoms of electrolyte imbalance and normal laboratory values of potassium, sodium, and chloride Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Objectives (cont’d) Explain the rationale for administering diuretics cautiously to older adults and individuals with impaired renal function, cirrhosis of the liver, or diabetes mellitus Develop objectives for patient education for patients taking loop, thiazide, and potassium-sparing diuretics List adverse effects that can be anticipated whenever a diuretic is administered Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Objectives (cont’d) State the nursing assessments needed to monitor therapeutic response or the development of common or serious adverse effects from diuretic therapy Cite alterations in diet that may be prescribed concurrently with loop, thiazide, or potassium-sparing diuretic therapy Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Renal Function: Assessment History of related causative disorders/factors History of current symptoms Pattern of urination Medication history Hydration status Electrolyte imbalance Often subtle changes, such as in mental status, muscle strength/cramps, tremors, nausea, general appearance Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Nursing Assessment for Hydration Status Evaluate for dehydration: skin turgor, oral mucous membranes Monitor laboratory values for changes Evaluate location of edema, signs of reduction Obtain daily weights Measure intake and output Common sites to check skin turgor are over the sternum, on the forehead and on the forearm. Weight gain that alerts the patient or nurse to increasing edema is generally 2 lb per day. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Electrolyte Imbalance Susceptible people: history of renal or cardiac disease, hormonal disorders, massive trauma or burns Assess mental status, muscle strength and cramps, tremors, nausea, general appearance Serum potassium < 3.5 mEq/L (hypokalemia), > 5.5 mEq/L (hyperkalemia) Serum sodium < 135 mEq/L (hyponatremia), > 145 mEq/L (hypernatremia) Potassium depletion can cause weakness of cardiovascular, respiratory, digestive, and skeletal muscles. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Patient Education Considerations Accurate measurement of fluid intake and output Purpose of diuresis Medication considerations Nutrition Health maintenance Written record/patient self-assessment form The prescriber orders furosemide 80 mg for a patient who had been retaining extra fluid after surgery. The nurse notes the following: BP of 142/88 (lying) and 108/60 (sitting); daily weight of 154 lb, a 1-lb drop from day before; serum potassium of 2.8 mEq/L. Should the nurse administer the furosemide? (The nurse should report the data to the charge nurse or the physician. The patient’s drop in weight is too much for 1 day; orthostatic blood pressure indicates volume depletion; potassium level shows diuresis is occurring too rapidly.) Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Carbonic Anhydrase Inhibitor Drug: acetazolamide (Diamox) Actions Weak diuretic; inhibits the enzyme carbonic anhydrase in kidney, brain, eye Uses Reduces intraocular pressure with glaucoma; reduce seizure activity with certain types of epilepsy See Chapters 19 and 43 for further discussion Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Sulfonamide-Type Loop Diuretics Actions Inhibit sodium and chloride reabsorption in ascending limb of the loop of Henle Uses Treat conditions such as edema resulting from heart failure, cirrhosis of the liver, renal disease Common adverse effects Oral irritation, dry mouth; orthostatic hypotension Serious adverse effects Gastric irritation, abdominal pain; electrolyte imbalance, dehydration; hyperuricemia; hyperglycemia; hives, pruritus, rash Drugs: bumetanide (Bumex), furosemide (Lasix), ethacrynic acid (Edecrin), torsemide (Demadex). Furosemide is also used to treat hypertension. Ethacrynic acid is more effective than other loop diuretics in patients with significant renal failure. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Thiazide Diuretics Actions Block reabsorption of sodium and chloride ions from the tubule Uses Treat edema associated with heart failure, renal disease, hepatic disease, pregnancy, obesity, premenstrual syndrome Common adverse effects Orthostatic hypotension Serious adverse effects Gastric irritation, electrolyte imbalance, hyperuricemia, hyperglycemia For specific drugs, see Tables 29-2 and 29-3. Used for more long-term management of heart failure and hypertension. Not strong diuretics; have a slow onset of action. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Potassium-Sparing Diuretics Drugs: amiloride (Midamor), spironolactone (Aldactone), triamterene (Dyrenium) Actions Induce retention of potassium; excrete sodium at the distal renal tubules Uses In combination with other diuretics to treat hypertension or heart failure, prevent hypokalemia Common and serious adverse effects Nausea, vomiting, anorexia, flatulence, headache, electrolyte imbalance, dehydration Instruct patients not to use salt substitutes, which are high in potassium, to prevent hyperkalemia. Contraindicated in patients with renal impairment because of high risk of hyperkalemia. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Combination Diuretic Products Drugs Spironolactone/hydrochlorothiazide (Aldactazide) Triamterene/hydrochlorothiazide (Dyazide, Maxzide) Amiloride/hydrochlorothiazide (Moduretic) Actions Potassium-sparing diuretics / thiazide diuretics Uses Promote diuresis while maintaining normal potassium levels Common adverse effects Hyperkalemia, hyponatremia For specific drugs, see Table 29-4. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.