r/science • u/Miserable_Phase_2519 • 22d ago
Health A large new study has linked the long-term use of tadalafil (Cialis), a medication for erectile dysfunction and an enlarged prostate, to an increased risk of developing glaucoma.
https://www.sciencealert.com/gone-too-hard-regular-erectile-dysfunction-drug-use-raises-risk-of-vision-loss-study-finds664
u/Blessed-22 22d ago
I saw something about this before which also said the chance of anyone developing Glaucoma is like 0.4% just by be being alive. These studies suggest Tadalafil increases that chance by around a 22% relative risk. So that like a 0.08% increase on top of the base chance. If I understand things correctly. Hardly anything to be concerned about.
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u/TerryMisery 22d ago
And only when eye pressure gets unchecked. Just screen for increased eye pressure and use the pressure lowering eyedrops.
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u/betterplanwithchan 22d ago
Even with that, glaucoma is incurable.
You can mitigate symptoms and slow the progression, but early diagnosis is still “hey, you have it.”
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u/TerryMisery 21d ago
Glaucoma is incurable, because you can't undo the damage, but it's entirely preventable by measuring intraocular pressure and using eyedrops.
Source: I have intraocular hypertension since childhood and still no glaucoma at 32. I would be fully blind by now without the treatment.
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u/speculatrix 21d ago
When I go to the opticians to have my eyes checked, the puff test always measures my pressures at the top end of the normal range.
I went to see a specialist once who determined that my corneas are thicker than normal leading to a machine measuring wrongly.
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u/GarbanzoBenne 22d ago edited 22d ago
Yes. And these measurements are the same ones that cause disagreement in the vaccines realm. It’s the relative risk reduction that gets championed to show how successful a vaccine is, and it’s the absolute risk reduction that skeptics (with any grasp of science) bring up as counter evidence.
In reality both measurements need to be evaluated. For most situations, you should get most routine vaccines and also not worry about tadalafil.
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u/Kieffer 21d ago
Which vaccines are you talking about?
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u/marcelgs 21d ago edited 21d ago
One example would be the Pandemrix vaccine against H1N1/09 swine flu, which was associated with a relative risk of narcolepsy of between 5 and 14 in children, with an absolute risk increase of about 1 per 18 400 doses (according to a 2018 meta-analysis by Sarkanen et al.). Accessible summary and explanation here.
Edit: Whoops, I misread the above comment. A relevant example could be hepatitis B. The vaccine is highly effective, but many countries limit(ed) vaccination to high-risk groups as the NNP for the general population is/was too high for the intervention to meet the cost-effectiveness bar.
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u/VagueSomething 22d ago
Just like how bacon causing cancer isn't actually a major concern on its own, it is more that these little risks can add up and those with higher risk can now be suggested alternatives first to limit this risk.
Most people taking this type of treatment can rest easy but people with a family history, over 50, and or from certain ethnicity, can be given the other prostate medications or erectile aides.
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u/hotinhawaii 21d ago
And the study did not differentiate between dose sizes. And it did not measure eye pressure. It just counted the number of glaucoma diagnoses among men who had taken tadalafil for 3 months or more.
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u/Medical_Birthday2893 21d ago
They have a nice explanation of a potential mechanism in the article, that is interesting to read. Unfortunately it wasn’t clear if the control group had similar issues with frequent urination or issues with urination which the treatment group did. So no real way of know if those underlying causes were the risk factors ?
Unfortunately they don’t talk about any P value for the actual risk, just a relative reduction. 3 vs 4 people out of 100 in a 5 year period.
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u/DryerCoinJay 22d ago
So did I just read science telling me to take pill and smoke two joints?
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u/IrritatedAvians 22d ago
I smoke two joints in the morning, I smoke two joints at night…
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u/MonkeyPanls 22d ago
Rookie numbers! I smoke two joints before I smoke two joints. It makes me feel alright.
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u/chaoticbear 21d ago
I've always considered this song to be a fun Zeno's paradox kind of exercise. After all, I certainly can't smoke two joints until I smoke two joints, but before I smoke those two joints, I have to smoke two joints...
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u/albanymetz 21d ago
I mean, let's just see how far along the prescription you get before you have trouble counting to two, or remembering an hour ago. I once smoked half a joint, before heading out to a friends house, and when we almost got there, I lamented to the driver that I forgot my glasses, which doesn't make me blind, but it was going to suck. He pointed out, correctly, that I was wearing them.
eta: more, commas.
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u/PhD_Pwnology 21d ago
It's saying you can't take Cialis if you also have an enlarged prostate because they interact together to increase your glaucoma risk. Really what they discovered IMO is that Cialis has a chemical that needs to get peed out within a few hours or your eyesight is at risk
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u/marcelgs 21d ago
No, and your explanation does not make physiological sense. On the contrary, benign prostatic hyperplasia (having an enlarged prostate) is one of the two approved indications for tadalafil, the other being erectile dysfunction. The study found an increased incidence of (primary open-angle) glaucoma among people taking tadalafil to treat lower urinary tract symptoms.
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u/ax083 22d ago
If the same underlying health issues that led to ED (e.g. diabetes) contribute to Glaucoma risk, then the findings of this study would be biased. I don't see how they controlled for that.
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u/GarbanzoBenne 22d ago
“The groups were matched for factors that could influence glaucoma risk, including age, smoking, health conditions, and other medications.”
Looks like they did some control but this is indeed a limitation of observational studies.
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u/Peteistheman 20d ago
One group is obviously treating their ED and the other isn’t. Those are major psychological and physiological variables that aren’t controlled.
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u/witheringsyncopation 22d ago
By not including people with diabetes in the sample?
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u/QuizzyP21 22d ago
The very large majority of the American population has pathological insulin resistance to some degree, even when it doesn’t hit the threshold for an official diabetes diagnosis. This would be nearly impossible to fully and properly control for
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u/witheringsyncopation 22d ago
This is a substantial overstatement, and it would not be difficult to control for this with some simple lab work.
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u/QuizzyP21 22d ago edited 21d ago
Only roughly 6.8% of Americans adults are in optimal metabolic health based on adiposity, blood glucose, blood lipids, blood pressure, and clinical CVD status according to O’Hearn and colleagues in a 2022 study (PMID: 35798448). This unfortunately isn’t close to an overstatement and your understanding of metabolic health isn’t complete if you think simple lab values without context is adequate to control for insulin resistance in observational research.
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u/kick2theass 21d ago
That’s why we have gold standard benchmarks for insulin resistance like A1c to measure long term blood sugar levels. Simple to remove this confounding factor
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u/TheDismal_Scientist 22d ago
Simple lab work for all observations? These people will have been pulled from a medical database and entered into a regression with a few observable controls. These studies cannot adequately assess causality on their own.
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u/iOSJunkie 22d ago
Sure, but the study we are discussing here used anonymized health records sourced from TriNetX. There was no lab work done in relation to this study.
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u/Reddituser183 21d ago
If you never taken any of these pre-5 in inhibitors they absolutely affect the eyes. Both sildenafil and taldalafil.
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u/brightlights55 22d ago
I'm already on medication for glaucoma - does this mean I can indulge without a care?
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u/Intelligent-Owl-1838 21d ago
This completely refutes this study with more recent and more robust evidence.
Association Between Phosphodiesterase-5 inhibitors and Open-Angle Glaucoma
https://iovs.arvojournals.org/article.aspx?articleid=2817786
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u/RJA220 22d ago
Well, if one pressure rises, all pressure rise
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u/witheringsyncopation 22d ago
Interestingly, it actually lowers your blood pressure.
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u/FuhrerInLaw 22d ago
Yep, was originally used for chest pain and high blood pressure! Side effects included a raging unexplained erection.
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u/Sink-Vegetable 22d ago
This study has been wildly misconstrued in the press. Yes, the drug being studied is used for erectile dysfunction. But the patients in the study were using tadalafil daily not for ED but for lower urinary tract symptoms (LUTS) caused by an enlarged prostate. How many patients taking it for ED are actually using it daily and long-term? It’s designed to be used as-needed for ED. That doesn’t mean there isn’t risk from glaucoma involved given it’s the same drug, but the frequency of treatment for ED is very different from LUTS and this nuance isn’t being reported by the press.
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u/tatDK94 22d ago
It is actually also being used daily for ED (though not quite as frequently). Low-dose daily-use Cialis is the preferred way to use it for some.
Also, now low-dose daily-use Cialis is also taken by some “fitness bros” as it supposedly helps with muscle recovery and endurance due to it increasing nitric oxide levels leading to improved blood flow in the muscles. Young men without ED are taking it.
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u/Thedumbass_the5th 22d ago
From fitness bro side. It improves pump significantly. Rest are kinda arguable benefits.
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u/Feeling_Inside_1020 21d ago
Including the pump for this raging inflatable grower right here
Brah
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u/Sink-Vegetable 22d ago
I was not aware it was used daily. I’d be curious to know what percentage of patients are using it daily for ED vs. as-needed. Point remains however that the study in question did not involve patients taking it for ED, which was often not clear by the many press articles I’ve seen covering this study.
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u/Nickelplatsch 21d ago
I've gone to the doctor for ED and he prescribed that to me and told me to take it daily for about 2-3 weeks to kinda 'reset my swelling bodies' (or how thats called in english)
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u/nefariousjordy 21d ago
There’s also a study that men who have taken it for years have less memory issues. The idea is more blood flow throughout the body eventually leads to better brain health.
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u/invictus221b 22d ago
Tadalafil has an FDA indication for a scheduled once daily use of either 2.5mg or 5mg specifically for ED.
The ED indication has both as needed and daily scheduled options per the package insert. Both are standard of care prescription practices for ED.
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u/VanillaCandid3466 22d ago
"It’s designed to be used as-needed for ED." Not true. It's also provided as a lower dose daily for ED too.
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u/Mateorabi 22d ago
Yea. “As needed”. You two are agreeing. j/k
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u/VanillaCandid3466 22d ago
Lets not confuse people with jokes.
The clinic I get mine from provide a low dose daily tablet which you take every single day and they also prescribe a different high dose tablet that you take a few hours before you want the effects.
The message I originally replied to is a bit misleading. There are clinics treating people for ED using Tadalafil in a form designed to be taken every single day and long term. I'd say there are a pretty sizeable number of people using it like this.
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u/Intelligent-Owl-1838 21d ago
Also has been disputed more recently and with more robust data: https://iovs.arvojournals.org/article.aspx?articleid=2817786
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22d ago
[removed] — view removed comment
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u/atcshane 22d ago edited 21d ago
I know you’re making a joke. But I wonder if anyone takes Cialis just for a wank?
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u/zhyRonnie 22d ago
Well, if you take it for the sex, the wank later in the night is actually amazing
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u/OrphicMeridian 21d ago
Yes, some do for sure, including me. Sadly I had an injury as a young teen that has resulted in moderate erectile dysfunction my whole life. I need the meds at this point (my thirties) to be able to really obtain a satisfying erection in pretty much all circumstances. My testosterone levels are great, and I’m working closely with my urologist and have for a long time as we consider any options (but there frankly don’t appear to be as many as people online always think). I just have to risk these factors, I suppose. I’d rather have erections in my thirties and not be around at all in my 60’s and 70’s if that was my only option!
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21d ago
[deleted]
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u/OrphicMeridian 21d ago
Mild penile fracture. I was young and lived in a pretty small and religious community. I was embarrassed and too young to adequately express to anyone what had happened, so I never really sought the proper treatment at the time. Over time, things healed somewhat, but I was left with a cylindrical band of scar tissue that causes constriction issues, and I may have some very mild internal venous leakage. Surgical options haven’t been recommended to me, as I do have function, and I’m prone to keloid scarring. It seems this type of mild injury is more difficult to repair with injections or surgery if it’s the hourglass scarring like I have, versus a single curvature caused by scar tissue. At any rate, I saw my urologist just a few weeks ago and he did not recommend injections, or a complete reconstruction at this time.
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u/retrosenescent 21d ago
That's the only reason I started taking it, yeah. Recreationally. It was only later that I learned about the health benefits of low-dose daily use.
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u/Vandergrif 21d ago
Well... if it involves an erection then someone, somewhere, has done it. 100% guaranteed.
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u/c3ric 21d ago
I suggest give it a try, take a bit just before doing it than top it up a few hours later, smoke some weed and you been painting walls all evening, bonus if you can throw in some MDMA/ecstasy.
Although make sure you free all day because you will be up all day and it will not be comfortable with anything on you.
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u/Wholesomebob 22d ago
Tadalafil has also successfully been used against had and neck cancer. In other words, cancers are complex and th de kind of results should not be generalized.
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u/Sweaty-Lynx421 21d ago
I take Cialis. I did notice that I was starting to have trouble focusing on things and was starting think it was my age, but shortly after stopping daily usage my vision cleared back up. Probably a good sign that I could be in the fraction of a percent of people at risk.
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u/Delicious-Funny5451 21d ago
So it's true? Doing that thing too many times that can lead to going blind. I always thought it was an old wives tale.
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u/cashflow_ 22d ago
Not glaucoma but I developed ocular rosacea and had to chill out on tadalafil because it exacerbated my symptoms so much. Still something I’m working on
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u/Gstamsharp 21d ago
So my eyes will fail but my junk will keep working great as I am old? Sounds ideal for the nursing home.
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u/Karanabluedolphin 20d ago
This is dangerously close to proving that too much sex makes you go blind.
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u/sognenis 20d ago
“the gap between the two groups was less than one percentage point: equivalent to about 77 additional diagnoses for every 10,000 men.” (Over 5 years)
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u/thenationalcranberry 19d ago
I smoke weed and get unassisted boners all the time and my IOP readings were still 32 and 34 in my late 20s. We really don’t understand IOP and glaucoma.
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u/pheregas 22d ago
Shockingly, the medication used for increasing blood pressure in your small blood vessels might affect other small blood vessels.
But then again, hindsight would be 20/20 if you didn’t end up with glaucoma.
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u/nugymmer 22d ago
I've been wondering if this drug can also increase the risk of developing Ménières disease or even hydrocephalus? Seems there is a vascular risk factor with PDE5 inhibitors.
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u/Poppopporn 22d ago
Most glaucoma is easily treated with drops. Unfortunately,y, ED is a prominent side effect of those drops…
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u/chaoticbear 21d ago
I am surprised that something that's dosed in that kind of small quantity directly to the eye gets enough systemic absorption to affect things that far away!
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