3 questions (need explanation!) - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
USMLE Articles
Go Back   USMLE Forums > USMLE Step 1 Forum

USMLE Step 1 Forum USMLE Step 1 Discussion Forum: Let's talk about anything related to USMLE Step 1 exam

Thread Tools Search this Thread Display Modes
Old 11-11-2015
USMLE Forums Scout
Steps History: ---
Posts: 33
Threads: 33
Thanked 3 Times in 2 Posts
Reputation: 13
Question 3 questions (need explanation!)

75 y.o. with a lot of drug for HTN, OA, and cholesterol. Which age-related decline in the following pharmacokinetic process is most likely to affect this treatment?
a. gastric absorption
b. hepatic glucorunidation
c. hepatic oxidative metabolism
d. protein binding in the serum
e. Renal tubular secretion
Phase1 is decreased in elderly so I thought C is the answer, but at the same time renal function is decreased so E might also be the answer.... What do you think?

In FA pg.240, it is stated that prostate cancer is more likely to metastazie to brain than melanoma.
However I also learned that carcinoma of the prostate almost never results in metastatic brain disease. What's the right sentence?

According to the explanation I attached, the clearance of both BUN and Cr are dercreased in CRF. However, if Cr is also lost in exrarenal sites(skin, GI), then shouldn't the serum BUN/Cr ratio increase? Obviously the ratio is <15 in intrinsic ACUTE renal failure, but I don't know if the explanation here is right in CRF.

(Thanks in advance!!)
Attached Thumbnails
3 questions (need explanation!)-1.jpg  
Reply With Quote Quick reply to this message

Old 11-11-2015
Linc's Avatar
USMLE Forums Scout
Steps History: 1+CK+CS
Posts: 20
Threads: 3
Thanked 14 Times in 7 Posts
Reputation: 24
Show Teeth BUN/Cr<15

3. Urea is what is lost in extra renal sites, NOT creatinine. In renal azotemia, creatinine and BUN backs up into the blood, but urea is lost in extra renal sites, that's why BUN/Cr<15.
Reply With Quote Quick reply to this message
The above post was thanked by:
linal (12-01-2015)


Quick Reply

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

Favorite USMLE Books
What USMLE books you really think are useful. Leave blank if you don't want to tell.
Where you live. Leave blank if you don't want to tell.


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Similar Threads
Thread Thread Starter Forum Replies Last Post
Need explanation to this question? kemoo USMLE Step 2 CK Forum 9 11-05-2015 11:38 PM
Need NBME 7 answers, with explanation, existing ones are double in many questions!!!! Pedro Rodrigo USMLE Step 2 CK Forum 0 09-12-2015 12:11 PM
most likely explanation ... tyagee USMLE Step 1 Forum 3 09-02-2014 04:35 PM
Explanation of PPD drpisho USMLE Step 1 Forum 4 12-10-2013 09:40 AM
Should we read the explanation for questions we answered right? mahganem USMLE Step 1 Forum 3 10-14-2010 07:13 PM

Find Us on Facebook
Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2019)