Flashcards in Antihypertensive Medications Deck (17):
What is the problem with Thiazides in patients who are in later stages of renal disease?
Late Stage = low GFR
• Thiazide lose efficacy in disease states that have progressed further
Why are higher doses of loop diuretic needed in CKD to achieve a natriuretic response?
1. Protein reduction in the plasma - so machinery available for delivery of Drug to PT
2. Inc. Protein in the urine means once drug actually gets to the PT it will just bind back to protein and get peed out without ever getting a chance to act
• drug class
Longer acting diuretic than Hydrochlorothiazide
At what GFR do we see loss of efficacy of thiazides?
What is it advantages to use and ACE in combination LOOP diuretics?
ACE causes hyperkalemia
LOOP causes hypOkalemia
Why is counseling about salt intake almost always necessary in CKD?
Because NEARLY ALL PTS. with CKD have SALT SENSITIVE HTN
Why is the response of a person with a serum creatinine of 3 mg/dL to a loop diuretic so much different than a normal person?
Lower GFR = harder to get it ACTIVELY SECRETED in the proximal tubular cells
If a type II diabetic has microalbuminemia, a BP of 130/80 and a serum creatinine of 1.0 mg/dL, what treatment would you give?
ACE or ARB, you must keep the BP low in these pts!!!
• Regardless of AMOUNT of protein in the urine you'll use these drugs for diabetics as long as they aren't pregnant
If you detect that someone has microalbuminuria, what should you do next?
• RETEST, exercise or infection could cause a pt. to have this
If you have patient with edema that is hyperkalemic from their ACE I, how can you solve this problem?
SOLVE BOTH problems by adding a diuretic. Thiazide or loop would probably work
How can we give patients with Kidney disease LOOP Is which cause decreased GFR and it be beneficial?
• Loop Diuretic Drops ∆P which would tend to Drop GFR
****But at the same time we are blocking angiotensin II which causes mesangial cell vasoconstriction and alters permeability ==> Causes Kf to go up****
Prevents us from dropping GFR too low
How can you measure how much salt someone is eating?
24 hr urine collection - no matter if they have reduced GFR intake still is equal to output
If person is putting on fluid later in the day what might you need to do?
• Multiple Doses per day of loop diuretics
What is the problem with using long term loop diuretic?
• what can you do to get around this?
• you get get Resistance - cells in the collecting duct hypertrophy
• Either Increase dose or combine with thiazide (sequential nephron blockade) to get around this
Why are CHF patients at increased risk for hyperkalemia?
• 2º hypERaldosteronism from decreased renal BF = more ENaC ==> More Na+ uptake
• Loop diuretics often used also increase distal Na+ delivery to ENaC
If an ACE I is not working to keep down BP in your African American pt. what medication would be most appropriate to supplement?
• Thiaizide Diuretic