High Altitude Performance Enhancement ?

[billbob]

Well, I heard that Viagra is supposed to help "high altitude performance", but exactly what does that mean? Is this a common med ?

[Alpinfox]

First result using google search

 

second google result

 

The researchers said the penis and the lungs both share a biochemical similarity. Both the penis and the lungs have lots of phospodiesterase, this is an enzyme which constricts blood vessels in the lungs. Viagra (sildenafil) stops the enzyme from working, the result being better erections and blood supply to the walls of the lungs.

 

Note that the mechanism of action of sildenafil with regards to the enhancement of pulmonary function is entirely distinct from the MOA of other "altitude" drugs such as diamox.

 

I wonder if the two together would give a climber a super-boost?

 

Hmmm.... I'm gonna write a grant. Maybe I can spend next season at Everest base camp.

 

[catbirdseat]

If this were rockclimbing.com, which it is not, there would ensue about ten pages of posts about pot smoking at altitude and one or two on Viagra.

[iluka]

Viagra (Sildenafil) and Cialis (Tadalafil) have been getting more attention in the research literature on high altitude illness lately. The study that was done at Everest Base Camp with Viagra showed that it could improve exercise performance at high altitude while a recent study that will be published in the next few months showed that Cialis can be used to prevent high altitude pulmonary edema in people known to be susceptible to the disorder (i.e. they've had it before). The drugs have no role with regard to acute mountain sickness or high altitude cerebral edema. Those diseases have a different cause and diamox (acetazolamide) and dexamethasone are the mainstays of prevention and treatment for those disorders.

 

Viagra and Tadalafil have a role at altitude by virtue of their effect on the blood vessels in the lungs. Specifically, they cause the blood vessels to dilate and bring down pulmonary vascular resistance and, therefore, the pulmonary artery pressures.

 

With regard to exercise performance, it's known that if you do a VO2max test at sea-level and then go up to high altitude, you will not reach the same VO2max. Can't be done. In that study at EBC, they gave people Viagra and then had them exercise. Exercise capacity went up but still not to the VO2max seen at sea-level. The hypothesis about why it worked was that by lowering the pulmonary artery pressures, the right side of the heart was under less strain and pumped better. If the right heart pumps better, the left side of the heart is happier and can deliver more cardiac output to exercising muscles. The improvement in VO2max in this study was pretty modest at best and it is unlikely someone would notice the difference between being on or off the drug while climbing at altitude... at least based on what they saw in this study.

 

With regard to high altitude pulmonary edema, it occurs because the blood pressures in the lungs (pulmonary artery pressures) rise too high. They rise in all people at altitude. It's just that in HAPE-susceptible folks, they go really high. Under the high pressure, the blood vessels begin to leak and protein and red blood cells move from the vessels into the lung tissue and air sacs. Tadalafil works vs. HAPE by bringing down the blood pressures and preventing this leakage. No one has studied if Viagra can be used to prevent HAPE but it has a similar mechanim of action as Tadalafil and would likely do the same.

 

No one has studied the effect of either medicine on promiscuity or sexual performance at EBC... perhaps that could be Alpinefox's research grant...

[Alpinfox]

Great post! Thanks.

 

I have a few questions for you:

 

I thought Diamox worked by inducing loss of sodium bicarb in urine, therefore inducing mild metabolic acidosis with the homeostatic response being increased respiration which results in boosted oxygenation of blood/tissues. Is that right?

 

If so, does diamox prevent AMS, HAPE, and HACE because with greater oxygenation of blood, the blood pressure doesn't need to be as high, therefore no fluid leakage into lungs/brain?

 

Is AMS really just a very mild form of HACE?

 

and finally, regarding:

[viagra/cialis] have no role with regard to acute mountain sickness or high altitude cerebral edema.

 

If both diamox and viagra/cialis boost oxygenation, why wouldn't they both counteract AMS, HAPE, and HACE?

 

HERE is a nice tutorial on high altitude physiology I found

[G-spotter]

I'd be happy to research this if Annabelle Bond was involved.

[iluka]

Glad the post was helpful.

 

Diamox seems to work against altitude illness by two means. The first is that it apparently stimulates the areas of the brain -- called the central chemoreceptors -- which control respiration such that you breath more at altitude than you would without the medication. More breathing means more oxygen down into the air sacs of the lung (alveoli). It's other mechanism of action is what you describe -- it creates a metabolic acidosis by causing loss of bicarbonate in the urine. The reason that is useful is this: when you go to high altitude, the low oxgyen conditions in the environment serve as a trigger for you to breathe more. That's the appropriate response but by breathing more, you blow off the carbon dioxide in your blood. This causes the pH of the blood to rise (called a respiratory alkalosis). The high pH has some degree of inhibitory effect on the drive to breathe and tones down how much extra you breathe in response to the low oxygen conditions. By creating a metabolic acidosis, diamox helps bring the pH of the blood back down which helps restore the drive to breathe. If you breathe more... more oxygen gets down to the alveoli and into the blood stream.

 

How this translates into preventing AMS and HACE isn't entirely well known. I think the sense is that by keeping your breathing up where it should be, you get more oxygen into the blood and delivered to the tissues which helps prevent the symptoms of AMS and HACE from developing. AMS and HACE are not due to high pressures issue as with HAPE. The blood vessels in the brain appear to leak and edema fluid accumulates for other reasons. HAPE, on the other hand, is driven by the high pressures in the blood vessels in the lungs. So... if you can bring those pressures down, you can prevent HAPE from occuring. You can do that with medicines that cause these vessels to dilate (nifedipine, viagra, cialis) or by getting more oxygen into the air sacs in the lungs (the constriction of the blood vessels in the lungs is caused by low oxygen levels in the air sacs of the lung and, interestingly, is not due to the low oxygen levels in the blood itself).

 

There is some preliminary research going on now in animals and in humans which appears to show that diamox may also block this constriction of the blood vessels in the lungs and may, as a result, be able to play a role in HAPE prevention. It's all very preliminary work so I wouldn't rely on it for this purpose in someone with a history of HAPE going back to high altitude.

 

AMS and HACE are now thought to be the same disease... just different ends of the spectrum of severity.

 

In regard to your last question... viagra and cialis don't change the level of oxygen in the blood. They just cause the blood vessels in the lungs to dilate and bring the pulmonary artery pressures down. This helps the right heart pump better and send more blood to the left side of the heart, all of which helps the left heart due a better job pumping blood out to the body. The amount of oxygen in the blood hasn't improved, it's just that the heart is doing a better job of pumping around the little oxygen that's in there.

 

All long winded answers to your questions... hope they make sense.

[Alpinfox]

[Jens]

Great post and thread.

----------------------

How bad can HACE kill brain cells? When I was a little kid, I was like this child prodigy- I.Q. off the charts, playing Beethoven piano sonatas, winning national awards for writing literature, & lot of other stuff. When I was in my early teens, I raced up Mt.Rainier and got really really sick (bedridden for a week- & had to see a doctor!) and I've been as dumb as a brick ever since. This ain't a joke. Is this possible? I can't even think my way out of a tic-tac-toe match! And you guys have seen how bad I write!

-----------

The funny thing now is that I'm super super strong above 20,000 feet. Maybe I killed off a bunch of grey matter and have some room to expand inside my empty skull?

[cj001f]

Based on my recent experience Diamox is completely incompatible with me. I've heard similar stories of body incompatibility.

 

#1 - it railed my water consumption - from 2-4 liters a day to 8-10 liters. No other adverse affects (i.e. sun sensitivity, nausea, dizziness, etc)

 

#2 - it didn't reduce the altitude symptoms. Still had nasty headaches, etc. (I was in Peru, went from 0m to 4750m in 4 days, spent 9 days >4000m with full pack)

[dtw]

Post deleted by fern

[iluka]

Based on my recent experience Diamox is completely incompatible with me. I've heard similar stories of body incompatibility.

 

#1 - it railed my water consumption - from 2-4 liters a day to 8-10 liters. No other adverse affects (i.e. sun sensitivity, nausea, dizziness, etc)

 

#2 - it didn't reduce the altitude symptoms. Still had nasty headaches, etc. (I was in Peru, went from 0m to 4750m in 4 days, spent 9 days >4000m with full pack)

 

Diamox doesn't agree with everyone but most people tolerate it pretty well. It is a diuretic (water pill) so you do urinate more while you're on it than you would otherwise so it is possible to get dehydrated. It isn't as powerful a diuretic as Lasix so people don't usually urinate huge amounts but it is still more than if you didn't take it. It's usually a good idea to drink more while you're on it. Whether that has to be another 4 L per day... ?

 

Diamox doesn't prevent AMS in everyone. If you look at the studies, it isn't 100% effective but many fewer people on the medicine get AMS when compared to people who don't take it. An alternative would be to try Dexamethasone. You can take 2 mg every 6 hours or 4 mg twice a day.

 

4 days to 4750 m (15,400 ft) is also pretty fast for some people. Even while taking Diamox, if you go too high too fast you can get sick. Did you take any rest days along the way and sleep at the same elevation for a second night. By way of comparison, on the standard trek to Everest Base Camp in Nepal people start at 2800m and don't get to the elevation you hit until Day 6 or later with a few rest days along the way. Some can go faster and do fine. Others need longer time to avoid symptoms... the response varies a lot from person to person.

[chelle]

Based on my recent experience Diamox is completely incompatible with me. I've heard similar stories of body incompatibility.

 

#1 - it railed my water consumption - from 2-4 liters a day to 8-10 liters. No other adverse affects (i.e. sun sensitivity, nausea, dizziness, etc)

 

#2 - it didn't reduce the altitude symptoms. Still had nasty headaches, etc. (I was in Peru, went from 0m to 4750m in 4 days, spent 9 days >4000m with full pack)

 

What dosage strength were you taking?

 

Jens - your post is interesting. Not sure how much sarcasm about your prior abilities is in your post but I have often wondered the same thing. I used to have a really good memory and fine motor coordination. After spending some 30+ nights above 12,000 over a 4 year period my memory and motor skills are not the same. I've always been pretty conservative about acclimatization becuase I can't take diamox because I am allergic to sulfa drugs, and I have never been sick at altitude. I still think I killed some brain cells while up there though.

[billbob]

Geez, I'm suprised by the knowledge base here, expected a ton of spray or adolescent jokes, was almost afraid to post the query. Nice to know there are intelligent people here, cerebral hypoxics notwithstanding.

[pup_on_the_mountain]

Thanks for all the info .

[hopalong]

I'm really glad I came accross this thread!

[DanielHarro]

For high altitude situations, can woman take viagra??

[catbirdseat]

For high altitude situations, can woman take viagra??

Of course they could. It would have the same effect on the lungs.

 

I should mention that Viagra and Cialis are PDE5 inhibitors. While there is PDE5 in the lungs, there are other isoforms like PDE4 which are more prevalent, I think. My understanding is that some of the drugs being developed for chronic pulmonary artery hypertension (PAH) are targetting PDE4 which is thought to be the main player.

 

These drugs if approved could be even more effective at treating HAPE.

 

Canada has approved an endothelin inhibitor Tracleer (bosentan) for PAH. That drug works by an entirely different mechanism. There is some animal data to suggest that it might be effective against HAPE.

[iluka]

For high altitude situations, can woman take viagra??

 

Yes. Women can take this class of medications to prevent HAPE. Keep in mind that only Tadalafil (Cialis) has been shown to prevent HAPE in HAPE-susceptible people (i.e. with a history of having had the problem before at high altitude). Sildenafil (Viagra) has not been studied for the purpose yet but I suspect that because it works the same way, it will have the same beneficial effect. Neither Tadalafil or Sildenafil have been studied for treatment purposes. Given their mechanism of action, they should be useful for treatment as well but this has not been put to the test in a research study yet.

 

 

Canada has approved an endothelin inhibitor Tracleer (bosentan) for PAH. That drug works by an entirely different mechanism. There is some animal data to suggest that it might be effective against HAPE.

 

Bosentan is already being used extensively in the U.S to treat pulmonary hypertension. It is fantastically expensive, on the order of 10s of thousands of dollars per year. There was just a trial released in the journal Circulation, looking at its role in altitude illness in humans and the results were not that great. In the end, with it's super high cost, I'm not sure it's worth the bother since there are already many effective and much less expensive options out there (acetazolamide, dexamethasone, nifedipine, tadalafil) for prevention of the various forms of altitude illness.

[iluka]

If people have interest in hearing more about all this...

 

http://www.cascadeclimbers.com/threadz/s...;vc=#Post614434

[DanielHarro]

how does one go about getting such drugs??? I am talking about Diamox, Viagra, Cialis ect... And what about good pain killers if something really bad happens like you break your leg or something????

[iluka]

how does one go about getting such drugs??? I am talking about Diamox, Viagra, Cialis ect... And what about good pain killers if something really bad happens like you break your leg or something????

 

Any physician can prescribe these medicines. One problem that people often run into, though, is that their physician might not know much about altitude illness and as a result may not know the proper doses and how to take the medications. Physicians at travel clinics might do better in this regard, although, there is some variable practices there as well. The key is to make sure your provider knows this information or where to get it and, if they can't to find someone who knows about it. To get the proper doses yourself, you can consult various references/guides. There is a great review article on altitude illness which has the drugs and their doses in the New England Journal of Medicine from 2001 by Hackett and Roach. A link to the citation is: http://content.nejm.org/cgi/content/extract/345/2/107

 

You can use this yourself or refer your physician to this if they need the information.

 

As for pain medications, if you want to evacuate someone with a broken bone, you are going to want to have a supply of narcotic medications in your first aid kit. Tylenol or I-B-Mopin' (Ibuprofen) won't cut it for such severe injuries. Your doctor should be able to write a prescription for that too provided you explain the need for it adequately.

[DanielHarro]

thanks for the info!! Its a great help!! Here is another random question, say that I want to spend 3-4 months in South America climbing and such, is there some limit to how many times I go up to altitude(above 15,000ish) in 3-4 months??

[iluka]

thanks for the info!! Its a great help!! Here is another random question, say that I want to spend 3-4 months in South America climbing and such, is there some limit to how many times I go up to altitude(above 15,000ish) in 3-4 months??

 

There shouldn't be a problem with doing this at the elevations you're talking about.

 

In fact, you'll find that if you are staying at relatively high elevations between all your climbs (i.e. not coming back to sea-level for long periods of time) you will become quite acclimatized to the altitude and, as a result, on your subsequent trips your risk of altitude illness will go down and you should find your exercise tolerance improving. You'll also find that when you finally return to sea-level at the end of your trip, exercise and climbing will be a lot of fun for a few weeks as your high hematocrit (blood count) will give you plenty of oxygen delivery capacity and improved exercise tolerance. It doesn't last for that long but it will provide you with some idea why elite athletes blood dope etc.