
Persistent erectile dysfunction in men exposed to finasteride, or dutasteride - noshbrinken
https://peerj.com/articles/3020/
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laichzeit0
This study is fucked, to put it bluntly. They're lumping together Fin and Dut
and people taking 5mg Fin. Most people taking Fin for MPB take 1mg Fin, for
example.

You can actually not draw any conclusions from this paper other than, don't
use Dutesteride unless you're male to female transitioning and don't go above
1.25mg finasteride if you want to keep your hair and your dick.

But it just confounds everything together, it's a terrible study.

~~~
throwaway6111
0.8% of a 4000+ sample size had PED with the regular dosage for baldness
treatment. That's absurdly low and pretty much confirms that though the risk
is there, it's highly unlikely. Its even more ridiculous that 1.4% of the
ENTIRE sample size (over 11,000 people) taking less than or equal to 1.25mg of
fin, greater than 1.25mg of fin, and dutasteride reported persistent ED.

As a fin user I actually find this data to be re-assuring.

~~~
laichzeit0
The criterion of PED is also vague. It's basically asking people do they think
their dicks are broken. There's enough guys going on Noporn/Nofap routines
because they couldn't get it up one night with a girl because they're so used
to watching porn and jerking off that real sex is too weird, and one bad
experience and now they're convinced they have ED.

If you tell a guy suffering from baldness that there's "a good chance you're
gonna break your dick if you drink this pill" you've already biased your
study. Blind study is the only way.

I'm not suggesting there is no risk, at this point the numbers are just a
joke. This study is another example of how to NOT to do it.

~~~
throwaway6111
They're also just doing analysis on a static data set.

> PED was determined by manual review of medical narratives for all subjects
> with ED. Risk of an adverse effect was expressed as number needed to harm
> (NNH).

So this doesn't rule out the possibility of the subjects' mental state
affecting their ED.

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KVFinn
A little strange to see this at the very top of the site, doesn't look like
anything particularly interesting?

~~~
rosser
My theory: it's a back-handed jab at President Trump, as he's reported to be a
user of Propecia for hair loss. Overtly political stories are usually flagged
off the front page quickly, but this is "just" a journal article.

(Note: I'm not a Trump supporter — quite the opposite. I just don't like
round-about mocking: "Oh, he can't get it up. That must be why he's such a
jerk!")

~~~
pseudalopex
My theory: an overwhelming majority of HN readers are men, many of whom have
taken or considered taking finasteride.

------
throwaway6111
> Among men 16–42 years old and exposed to finasteride ≤1.25 mg/day, 34 of
> 4,284 (0.8%) developed PED (persistence median 1,534 days, IQR 651–2,351
> days); the multivariable model predicting PED had one variable: duration of
> 5α-RI exposure

So less than 1% of finasteride users get PED. PED was already a known side
effect. That's good it's being confirmed with data, but aren't the odds still
very low that this would happen to fin users? As a fin user myself, I haven't
experienced any of the sexual sides so I'm wondering if there's any new take-
away from this.

When I look at this as a fin user, I'm personally happy to see that the data
says its so unlikely.

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hartator
Where is commonly found finasteride or dustaride?

~~~
moh_maya
they are used for treating prostrate enlargement as well as hair loss in men,
among other things..

[https://en.wikipedia.org/wiki/Finasteride](https://en.wikipedia.org/wiki/Finasteride)
[https://en.wikipedia.org/wiki/Dutasteride](https://en.wikipedia.org/wiki/Dutasteride)

But I don't think that this side-effect was unknown. ED / sexual dysfunction
is a documented side effect for both the drugs in a significant percentage of
the patient population.

~~~
zedred
I think this study is exploring "persistent" ED, which is less known. ED is a
documented side effect, but this shows that some men continue to experience ED
even _after_ they stop taking the drug.

~~~
rosser
The linked Wikipedia article cites references to _persistent_ ED and
diminished libido common enough to warrant changing the labeling on the drug
in _2014_.

So, yes, this study is exploring that side effect, but it's inaccurate to call
it "less known".

EDIT: fixed some word salad phrasing.

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XNOVRJ
Can anyone knowledgeable guess at the mechanism of action?

~~~
rosser
The Wikipedia article says it prevents conversion of testosterone into
dihydrotestosterone by the enzyme 5α-reductase, and also affects the GABA
system. Particularly relevant quote: "Reduction of GABA-A receptor activation
by these neurosteroids has been implicated in depression, anxiety, and sexual
dysfunction." More specific than that is _way_ beyond my understanding of
these things.

[https://en.wikipedia.org/wiki/Finasteride#Mechanism_of_actio...](https://en.wikipedia.org/wiki/Finasteride#Mechanism_of_action)

~~~
XNOVRJ
That's fine, but how would that account for PED?

~~~
rosser
Like I said, any more is beyond my level of understanding of these things. All
I can say for sure is that the GABA system is incredibly important, and kinda
delicate.

Read up on _delirium tremens_ , for example: long-term alcoholics, and
benzodiazepine and barbiturate addicts need to be really careful in stopping
their use of those drugs — they could die if they aren't. Those drugs also
affect the GABA system.

Maybe the long-term down-regulation of some aspect of GABA-A metabolism by
finasteride's preventing the formation of an agonist for those receptors
becomes permanent or semi-permanent after a while? I really don't know.

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firebones
I'm guessing this is a dig at someone of prominence having notable hair who is
in US news who is on one of the drugs mentioned.

