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Q: Detectability of Finasteride (Propecia) in urine test ( Answered 5 out of 5 stars,   0 Comments )
Subject: Detectability of Finasteride (Propecia) in urine test
Category: Health > Medicine
Asked by: bubbahotep-ga
List Price: $20.00
Posted: 17 May 2006 18:04 PDT
Expires: 16 Jun 2006 18:04 PDT
Question ID: 729897
For how long after using Finasteride (1 mg / daily), is the use of it
detectable in a urine sample? I am a 30 year old male and have used
Propecia (which contains Finasteride) to prevent hairloss for some
years. Finasteride has been added to the list of banned substances in
sports, and I need to know how long before testing should I
discontinue the use of Propecia. Thanks!
Subject: Re: Detectability of Finasteride (Propecia) in urine test
Answered By: welte-ga on 17 May 2006 21:19 PDT
Rated:5 out of 5 stars
Hi bubbahotep-ga, and thanks for your question.

The short answer to your question is about 90 hours.  Here is a good
poster presentation discussing the detection of finasteride in the
urine and the issues that have led to it's being banned in sports
(i.e., it's use as a masking agent for steroids):

A second paper gives a terminal half-life of 4.7-7.1 hours (see Table
2 below).  The terminal half-life is the time to reduce the serum
concentration by 1/2 after equilibrium is reached.  Allowing about 2
hours to reach equilibrium, 88 hours would correspond to at least
about 12.3 terminal half-lives or a plasma concentration of about
1/154th of the peak concentration (0.65%), so the numbers appear to be
comparable to one another.

Gormley GJ. Finasteride: a clinical review.  Biomed Pharmacother.
1995;49(7-8):319-24. Review.

Table 2:

As you can see, there is nearly a factor of 2 in the range of
metabolism finasteride, so I would suggest trying a 90 hour abstinence
from finasteride and asking your physician to perform a urine drug
screen for you to see if it is positive, before putting yourself in
the position of potentially having a positive or borderline test
before a sports event.

I hope this information is helpful.  Please feel free to request
clarification prior to rating.



Search strategy:

(finasteride OR propecia) urine metabolism detection -rat -dog

PubMed / Ovid searches for finasteride metabolism
bubbahotep-ga rated this answer:5 out of 5 stars and gave an additional tip of: $20.00
Thanks a lot, this was exactly what i was looking for!

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