Mt. Whitney Portal Store & Hostel Forums General Mt. Whitney Portal Store Message Board Diamox Lessens Brain Damage

Question--someone posted on here a while back a study or some such about high altitude and brain damage--more specifically, it was a high rate of change in altitude being associated with brain damage. As I recall the "study" was largely anecdotal. Anyway, since AMS and HACE are basically caused by edema(?), wouldn't it stand to reason that Diamox, a diuretic, would lessen the chances of said brain damage?

Discuss...

I took diamox for a few days on Kilimanjaro. I think it is a horrible drug. I couldn't stay hydrated enough to compensate for how much it caused me to urinate. It didn't improve my headache and it gave me terrible full body paresthesias. I think it actually caused brain damage.

A- yes, logic would say that. However logic and reality are two different things. For example, other diuretics appear to have no protective effect for AMS, and one would think they would. So the effect of Diamox seems to be independent of it's diuretic effect.

Snowman, that is very typical when people take the glaucoma dosage, instead of the most modern AMS dosage, which is something like 1/8th of the other. On the much lower modern dosage, the side effects are much more minor and tolerable, but don't appear to diminish the protection.

steelfrog, a great overview of AMS and the two deadly altitude-related edemas can be found here , as well as a nice comparison of what acetazolamide (Diamox) and dexamathasone do and don't do. I've personally never taken either, but I know folks who have used Diamox (including my wife) and, as Ken says, the dosage is really key in the degree/severity of the side effects, but not necessarily in the effectiveness of the drug helping the body to acclimate. One tablet may bring on those raging side effects while helping you acclimate; a half or even a quarter of a tablet may assist your acclimation just as effectively, without feeling like your body's being bombarded. Like the old Brylcreem commercial used to say, "a little dab'll do ya!"

One thing I learned reading that web page several months ago is that it's a myth that there is "less" oxygen in the air at higher altitude than lower. The ratio of oxygen in the air stays pretty much the same but, due to the expansion of the air caused by the lower pressure, there is less oxygen (and every other gas) in each breath you take in. The net effect on humans is essentially the same, but for a different reason than I thought. Maybe this knowledge will win me a bar bet or two . . .

And on the subject of high altitude brain damage, I had a visual "ah-ha!" moment a couple of weeks ago. After waking up at around 12,000 feet on the Whitney Trail I set water boiling for my absolutely-no-questions-asked, must-have-or-I'll-die morning coffee (the caffeine thread running concurrently pleases me greatly, by the way). When I fished out a single-serve packet of instant coffee the damn thing looked like a balloon. I just stared at it for a moment, remembering how nice and compact it looked when I packed it at 3500 feet. The change in ambient air pressure had caused the sealed packet to expand almost to bursting. Between my partner's coffee packets and mine - two different brands - they were all like that.

Then I thought about my brain and other near-and-dear biologicals that may still be carrying around air/oxygen ingested at higher pressure from a day or two prior, and how they were reacting to 12,000 feet. AMS, HAPE, HACE and all the rest made crystal clear sense to me at that moment, like never before!

Which is why some become especially gassy at high altitude.....(stay upwind!)

So that classic Blazing Saddles campfire scene was really filmed on Whitney? Better alert the Lone Pine Museum of Film History!

Note that you can't take any of those medications if you are allergic to sulpha-based medications.

Actually, I think it depends upon your sulfa allergy. My wife has carried an allergy to sulfa drugs for years, but the doctor gave her Diamox anyway since it is in a different category of sulfa than the antibiotics she had a reaction to many years ago. I can't provide the details as to the differences involved but her request for the drug, even though she knew about its sulfa derivation, came as a result of some very useful information Ken and Harvey posted a while back. Ken in particular, I believe, indicated that the classic sulfa allergy may not apply in many cases to acetazolamide. I'm sure they can explain why this isn't a classic "sulfa" drug, but that's beyond my pay grade.

Net result, she took Diamox for the first time a few weeks ago and suffered no reaction (other than the typical irritating side-effects most everyone seems to experience). I would encourage anyone interested in Diamox to discuss with their physician before assuming that a pre-existing sulfa allergy is an automatic disqualifier.

As an aside, she also asked for a couple of dex to take to the Sierra as an emergency AMS drug (she has a history of debilitating AMS at 14,000 feet), and got a firm, flat "no". No amount of benefit could outweigh the downside in her doctor's opinion. Guess the doc's never been in those shoes . . .

That's great information - thanks for sharing.

God help those who are interested:

February 9, 2006Gruchalla RS, Pirmohamed MN Engl J Med 2006; 354:601-609

"For patients who have a history of allergy to sulfonamide
antibiotics, concern has been raised
about the use of other sulfonamide-containing
drugs (diuretics, sulfonylureas, and celecoxib).
However, sulfonamide antimicrobial agents (sulfamethoxazole,
sulfadiazine, sulfisoxazole, and
sulfacetamide) differ from other sulfonamide containing
medications by having an aromatic
amine group at the N4 position and a substituted
ring at the N1 position; these groups are not
found in nonantibiotic sulfonamide-containing
drugs. Thus, despite product-labeling warnings,
cross-reactivity between these two groups of sulfonamides
is believed to be unlikely"

===================
So I believe that a challenge of diamox is a reasonable thing to try in a person with a history of "allergy to sulfa", best accomplished away from the field, where treatment is accessible in the unlikely event of need. If the previous allergy was a life-threatening event(very rare), it would probably best be carried out in a doctor's office.

The issue, as pointed out in a number of articles on the subject, is that people who have such severe allergic reactions may actually be suseptible to such reactions from many chemicals...it's a personal thing, not a chemical thing.

Thanks Ken! Don't really plan to use the stuff, but it's good to know. I just make a point to acclimate as best I can, and face it if I have to go down. Period.

Ken, like I said - way above my pay grade! But I recall you reviewing this in another post, and that's what spurred me to have my wife speak with her doctor about Diamox. Thanks!

bulldog's first post contains a link I often post, if anyone has not looked, please do.

Diamox works in more important ways than simple diuresis .

It is a carbonic anhydrase inhibitor, as such it not only changes ph of urine but also CSF (cerebro-spinal fluid). This beneficially stimulates brain respiratory-drive centers, the most important factor in survival in high altitude.

I'm in Mammoth, on my first day at altitude (coming from sea level) I hiked 7 hrs round trip up to Two Teats at 11,200 ft. Surprisingly no headache this year on day 1. Took a half Diamox when I got back down anyway since the symptoms can occur later, in fact I had a poor sleep night. Would love to contribute more on this thread, but I'll be backpacking a bunch, starting 8/4 and ending up at Whitney. Ken, will say hello to it for you. Harvey

Harvey, I'll be waving to you at the top!

Exactly!

First I want to comment on the allergy to sulfa and taking Diamox. I have sulfa allergy and taken low doses of Diamox with no allergic reaction.

Second the dosage of Diamox is the key. If you are doing it for pretention, all you is a very low dose. I rarely use it but if I do I take 62.5 mg which is 1/4 of the 250 mg pills. Typically people are taking too much and experiencing side-effects from the drug.

Then to take it? I take it before going to bed so it will help my breathing as I sleep (refer to article in bulldog's post).


The Institute for Altitude Medicine (IFAM):
Does High Altitude Cause Brain Damage?
Much recent negative press has been generated regarding brain MRI changes in high altitude climbers. Appropriate quantitative measurements of these MRI changes have not been done. The significance of these changes is unknown and has not been correlated with neurocognitive testing. Statements that altitude causes brain damage are unfounded. We will perform a study on a group of climbers already planning on climbing Denali in 2008. These subjects will undergo pre and post climb MRIs of their brains as well as neurocognitive testing to determine if any significant changes occur after a single climb to high altitude.

Well here's a personal experience report on diamox and the sulfa issue, and sleep apnea (recognizing that others' experiences may differ).

After the last email train re diamox, dex, etc. I picked up some diamox, though not necessarily planning to take it (I've previously had no problems at 10,000-13,000 feet during the day time, or sleeping at 10,000 feet). Because I have had skin allergies in reaction to sulfa antibiotics, I tried a few doses of diamox at sea level, and no problems developed.

Last week, I planned to climb White Mountain, and carried the diamox to the trailhead (almost 12,000 feet), again, not planning to use it.* Despite having spent the two previous days and nights at 10,000-plus feet (Tioga Pass area), I developed sleep apnea that night, which I suffered through for about five hours before figuring out what was happening. I then took a single 125 mg dose of diamox, and within an hour fell asleep and slept fine for the few hours remaining. White Mountain was a relatively easy hike the next day (thanks in part to glorious weather).

I am not sure whether or not this single experience means I will always develop sleep apnea at 12,000 feet. Before assuming I need diamox to sleep at that elevation, I am inclined to do a few more tests (always carrying diamox). If someone has insight on that issue, though, I'd appreciate it (i.e., whether, having had apnea develop on one occasion at 12,000 feet despite two prior nights at 10,000 feet, one is likely to have apnea the next time one tries to sleep at 12,000 feet).

*As I understand it, because diamox is primarily for prophylactic use (to help prevent AMS rather than to treat it), the usual use involves taking it for a few days prior to gaining altitude. But I just chose to carry it in case mild AMS symptoms developed.

The general thought is that if a person has had a problem with any AMS symptom, they are at a higher risk of getting AMS in the future....but in an unpredictable way. For any specific time, maybe, maybe not. I guess there are a lot of interrelating factors involved, not well understood.

While the "classic" use is prophylactic, it is certainly used, and useful, when one develops symptoms on the hill. Particularly in the case of a previous problem, I think carrying it "in case" is very reasonable, and I usually do.

The breathing difficulty you experienced is called Cheyne-Stokes respiration. I used Diamox to prevent it on Aconcagua (125 mg before bed the first night at each new sleeping elevation). And I'm pretty sure the business about taking it for a few days prior is obsolete info (just like the old recommendations to take large doses). Diamox is a fast-acting drug.

No, that is still current. While the Diamox works rapidly on the sleeping issue, the other aspects of AMS are not so easily adjusted, and a couple days advance diamox is definitely better for that.

Ken - you said, "I think carrying it "in case" is very reasonable, and I usually do."

That raises the question of shelf life, if not used and stored for awhile. Any insights on that?

Thank You.