FA/ USMLE Rx ANSWER BOTHERS ME. PLEASE READ - expo

[ArchivalUser]

3. An 80 year old woman with a history of acute myocardial infarction and congestive heart failure presents to the emergency department with a chief compliant of fevers and lethargy. After a full work up a urinalysis is performed yielding an alkalotic specimen with increased sodium chloride, potassium, and calcium concentrations. Which of the following could cause these results?
A. Acetazolamide
B. Furosemide
C. Spironolactione
D. Thiazides
E. Triamterene

FA ANSWER: B
3. B Furosemide and other loop diuretics can cause this. As with all diuretics urinary sodium, chloride will be increased. Diuretics increase potassium excretion (exception:potassium sparing diuretics!). Loops such as furosemide, create alkaline urine with excretion of high concentration of calcium “ œLoops Lose calcium.
Acetazolamide “ lowers pH with Carbonic Anhydrase inhibition.
Spironolactone,Triamterene “ potassium sparing diuretic would result in low potassium in urine.
Thiazides “ cause decreased urinary calcium

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THE pH OF THE URINE IS BOTHERING ME.

The question states that the urine was "basic = alkalotic".
If the urine is basic, than Acetazolamide is the best answer.
Acetazolamide is a CA inhibitor. Therefore, it will throw HCO3- into urine (bicarbonaturia).
As a result, Urine will be basic and Blood will be acidic.

Loops do not make the urine basic. Loops make the blood basic.
Loops lose H+ into urine. Therefore, Loops make blood basic due to loss H+ and urine
basic.

Both Loop and CAI share these qualities: Lose K+ and Sulfa allergies

Finally, Acetazolamide causes renal stones so it is losing Ca++ as well.

Am I missing something? Your answer is from FA themselves...so ?

[ArchivalUser]

Acetazolamide do not cause increase urinary Ca .......
where you read that it cause renal stone. Kaplan?

[ArchivalUser]

KAPLAN
DIURETICS OF PHARM
States that Acetazolamide causes hypercalcuria + causes renal stones. (p.117 2002)

What about the Urine pH ? That is the real problem with the question + answer.

[ArchivalUser]

sorry typed too fast

Loops should read:

Loops do not make the urine basic. Loops make the blood basic.
Loops lose H+ into urine. Therefore, Loops make blood basic due to loss H+ and urine
ACIDIC.

[ArchivalUser]

Well if u have 2002 notes then look at 118 page second paragraph ...
loop diuretic increases urinary level of Na, K, Ca, Mg, and Cl BUT ITS NOT WRITTEN ABOUT H
its mean that urine Ph will be basic... GOT it????

[ArchivalUser]

Thanks for instructing me to page 118.

On the next sentence, Kaplan writes:
"Deliver of increase Na+ load [b/c of LOOP diuretic ] downstream enhances loss K+
ions and PROTONS at Collecting Tubules.

The LOOPS urine to be basic doesn't make sense:
1. Loops make blood more basic b/c they lose H+. = urine acidic
2. Loops decrease amount of HCO3- in urine = urine acidic (page 121 of Kaplan)

Acetazolamide clearly fits all requirements of question.

Anyone? why did FA choose this answer? please.

[ArchivalUser]

expo

i HAve the same doubt .newonw posted that q n i marked it acetazolamide.u have given right explanation from kaplan .i checked from kap too n even if u see v first page of diuretic in kap it says

Diuretics that block Na+ absorption above CT will inc Na+ load to the CT n CD .resulting in incloss of K+n associated loss of H+ in case of loop n thiazide .

[ArchivalUser]

hey saan
thanks for taking time to reply to my post.

yeah, i didn't know if i was confused or could the question be mistaken.
At least, you see what i'm saying.
I guess we won't know but it was a good review.
good luck.