1. Diuretics

2. Diuretics 0 Work by blocking reabsorption of Na and CL 0 Drugs whose site of action is early in the nephron produce the greatest diuresis 0 Adverse effects 0 Hypovolemia 0 Acid-base imbalance 0 Electrolyte disturbance

4. Classification of Diuretics 0 Loop (high ceiling) 0 Thiazide 0 Osmotic 0 K sparing

5. Osmotics 0 mannitol (Osmitrol)- prototype 0 Properties of Osmotics: 0 drug is freely filtered at glomerulus 0 Uses 0 to prevent acute renal failure 0 to decrease ICP 0 to decrease IOP

7. Mechanism of Action 0 Creates strong osmotic force within lumen of nephron 0  osmotic pull in the circulatory system 0 Moves fluid from interstitial space and intracellular space to vascular compartment

8. 0 Adverse Effects 0 circulatory overload initially 0 Nursing Implications 0 Assess s/s overload 0 Use extreme caution in pts prone to pulmonary edema 0 Avoid extravasation

9. Loop Diuretics 0 furosemide (Lasix) - prototype 0 most effective of all diuretics 0 preferred over thiazides 0 have high ceiling effect 0 ability to work even with low renal blood flow and GFR 0 Used to tx edematous states, HTN, prevent ARF

11. Mechanism of Action 0 Inhibits Na and Cl reabsorption in the loop of Henle 0 Increases calcium and magnesium excretion

12. Adverse Effects 0 dehydration 0 hypotension 0 F/E imbalance 0 can produce excessive loss of electrolytes, especially sodium, chloride, and potassium. 0 Caution with digoxin 0 Ototoxicity in high doses - transient hearing loss

13. N.I. specific to loop diurectics 0 po onset begins within 60 minutes and last 6 hours (Lasix is named Lasix because it “lasts 6 hours) 0 IV onset begins within 5 minutes and last 2 hours 0 Monitor Electrolytes 0 Monitor blood pressure 0 I&O 0 Avoid administration late in the day

14. Thiazide Diuretics 0 chlorothiazide (Diuril)- prototype 0 maximum effect is lower than maximum effect of loop diuretics 0 used for edematous states and HTN

16. Mechanism of Action 0 Blocks reabsorption of sodium and chloride in the distal convoluted tubule 0 Adverse Effects 0 almost identical to loop 0 Hypokalemia, hyponatremia, hypochloremia 0 dehydration

17. N.I. specific for thiazides 0 Must have adequate kidney function for drug to work (because works on distal renal tubule) 0 most are given po (not IV) and onset of action within 2 hours 0 Thiazides are being combined with other drugs to control BP (thiazide + ACE Inhibitor, thiazide + beta blocker, thiazide + potassium-sparing)

18. Potassium Sparing Diuretics 0 spironolactone (Aldactone) - prototype 0 only modest diuretic response 0 produce a substantial decrease in K+ excretion 0 frequently used in combination with loop or thiazide diuretics for HTN or edema

21. Mechanism of Action 0 Blocks action of aldosterone in the distal nephron; results in retention of potassium and increased excretion of sodium 0 Adverse Effects 0 hyperkalemia 0 Teach patient to avoid salt substitutes which have high potassium content 0 Avoid foods high in potassium

22. Nursing Implications for Diuretic Therapy 0 “Accurate” I and O 0 U.O. should be 1 ml/kg/hr or 30ml/hr 0 Weigh daily - report weight loss or gain of 5 lbs in a week. “Remember 1 liter of fluid =2.2 lb” 0 monitor young and old carefully - elderly more sensitive

23. 0 Evaluate lab values for dehydration 0 Elevated BUN in relation to serum creatinine 0 elevated hematocrit, hemoglobin, and sedimentation (“sed”) rate 0 electrolyte imbalance 0 Urine specific gravity will increase

24. 0 Fall precautions - increased risk of orthostatic hypotension (hypovolemia) 0 monitor b/p for orthostatic hypotension 0 Schedule meds during day - prevent nocturia 0 Avoid alcohol - aggravate hypotension 0 May be abused by patients for weight lost

25. 0 Limit sodium intake 0 Increase or decrease potassium - depending on diuretic (know these foods!) 0 Teach s/s of electrolyte imbalances 0 Assess for s/s dehydration 0 poor skin turgor 0 marked thirst 0 dry mucous membranes 0 shocklike symptoms (tachycardia, tachypnea, and later, decreased BP due to hypovolemia)

26. Name the four classifications of diuretics. Out of these four which one raises the osmotic pressure of the glomerular filtrate ?

27. 0 The four classifications are: osmotic, loop, K sparing, thiazide 0 Osmotic diuretics (Mannitol) causes diuresis in the proximal convoluting tubule by osmotic force. This inhibits the reabsorption of Na and water.

28. 0 Which diuretic is the most effective? 0 What patients are most likely to receive this medication?

29. 0 Lasix is the most effective diuretic. It is a loop diuretic- it works in the ascending limb of the loop of Henle 0 Lasix is given to patients with hypertension, CHF, and to prevent or treat acute renal failure. It has the ability to work in the kidney even when renal perfusion is reduced.

30. 0 What are the adverse effects of Lasix?

31. 0 Volume depletion due to the effectiveness of the medication 0 Hypotension- always check blood pressure before giving this medication especially if the patient is receiving other antihypertensives 0 Loss of electrolytes- particularly K, Can lose Na, Ca, Mg and Cl as well 0 Ototoxic 0 Caution with digoxin because of the risk of hypokalemia and protein binding

32. 0 Patients who take Lasix long term are often prescribed supplemental potassium. Dietary intake of K rich foods is also encouraged. What foods are high in potassium?

33. 0 White beans 0 Spinach 0 Bananas 0 Avocados 0 Dried apricots 0 Winter squash 0 Sweet potatoes 0 Orange Juice (which is why you won’t see OJ in the hospital refrigerator especially for renal patients)

34. 0 Mrs. Jones in acute renal failure following a myocardial infarction. The physician orders a Thiazide diuretic. Is this the best medication for the patient?

35. 0 No, this is not the best medication. Although Thiazide diuretics work in much the same way and can be very effective diuretics, they do not work well unless the kidney is well perfused. In acute renal failure associated with myocardial infarction, the blood flow to the kidney is compromised. Lasix is the best choice.

36. 0 Mr. Smith has been receiving Lasix oral for one month. He also receives a potassium supplement. He has a history of low potassium levels and has been hospitalized several times for electrolyte disturbances. The healthcare provider wants to add an additional diuretic to treat his uncontrollable hypertension. Which diuretic is the best choice?

37. 0 Potassium sparing diuretic 0 Although this classification only produces a modest diuretic effect, they do not increase the risk of K loss. In fact, when a patient is receiving only a K sparing diuretic you should look for a high K level. 0 Potassium sparing diuretics work in the late distal collecting tubule so they are the weakest. This is why they are often given in combination with other stronger diuretics. Mr. Smith may have hypokalemia if the Lasix dosage is increased so adding a K sparing diuretic is the best choice.

38. 0 Mrs. Jones is a patient with congestive heart failure and hypertension. She takes a beta blocker. Her physician feels that the beta blocker alone is not effective and wants to add a diuretic. Which diuretic will the physician most likely choose?

39. 0 Thiazide diuretic is the most likely choice. They are often combined with other medications to control blood pressure. 0 Thiazides can be given in conjunction with: beta blockers and ACE Inhibitors

40. 0 You are caring for a patient who was involved in a motor vehicle accident and has head trauma with increased intracranial pressure. Which diuretic will work most effectively to move fluid into the intravascular space ?

41. 0 Osmotic diuretics are recommended for increased intracranial pressure, increased intraocular pressure and to prevent acute renal failure. 0 Osmotics move fluid from the interstitial space and intracellular space into the vascular space. But watch out because this fluid shift can cause a hypervolemic state which may be harmful for patients with congestive heart failure. It is known to cause pulmonary edema and can cause a dilutional hyponatremia.