Haven't really seen this discussed on this board & neither on the DAN site. For the "baby boomers" out there.

I read an interesting article in Sunday's NY Times magazine having to do with a perplexing case that the docs couldn't figure out; why a wound wasn't healing. To make a long story short it turns out the culprit was excessive zinc intake in the vitamins he was taking which in turn lead to a inadequate absorption of copper which in turn prevented the healing...

What does this have to do with the above? Sometimes we could be taken meds which we think help us, but because of different or changed circumstances it could cause harm. Many times a diuretic component is added to hypertension meds...Specifically Avapro (no diuretic) & Avalide (with a diuretic). When I'm on Bonaire, I switch to Avapro. I suggest you learn about the meds you are taking.

Common sense dictates that you certainly may not need the diuretic component while breathing super dehydrated air, doing 2-3 dives per day in the dry Bonairean climate. Not to mention immersion diuresis together with perspiring in the sun..

We all know that dehydration is a major culprit in preventing adequate off-gassing. I wonder how many people who have gotten bent have also been taking diuretic meds which prevented proper hydration. My advice is to check with your doc & if warranted perhaps eschew diuretics while diving.

Vince,
Makes sense, but sometimes common sense and reality don't coincide. It would seem to make sense that diuretics such as hydrochlorthiazide decrease BP by reducing the amount of fluid in your system. In fact the precise mechanism is, as with many drugs, not well-understood but its anti-hypertensive effects are not primarily due to volume loss and people on diuretics who maintain good fluid intake are not dehydrated or volume-depleted. And the diuresis that occurs when diving will not have the same blood-pressure lowering effect that the thiazide diuretic does. I would just make sure to increase fluid intake to compensate for the volume loss due to heat and immersion diuresis.

My daughter went to Seacamp in Florida and was taught the rule "clear pee is happy pee". Words to live by.

But, as you said, check with your doc.

Now if you want to talk about the blood-pressure lowering effects of being on Bonaire...

Maybe we can get funding to research that!

-David

I would be happy to be the first guinea pig!! Are you saying, David, that it's not just the fluid loss, but what is contained in the fluid that lowers the BP? I understand the part of having to be hydrated, just wanted to clarify what you were saying.
A question here. My oldest son, Joshua (25) may be joining me in a trip to Bonaire next July and is truly very fit. He did have however, a spontaneous Pneumothorax (collapsed lung) in High School when he was 16 while taking his Spanish finals! Would he be allowed to dive? He loved diving prior to that, but hasn't had an opportunity to do so since. Try getting him to a doctor while 7 states away! Didn't know if any BT'rs have had any experience with this. Would like to address it before the last minute. I know, he's a big boy, but still my boy!

Thanks David..I'm sure we all appreciate your professional input on this subject which as I indicated have not really seen addressed from this particular angle at the DAN website.
I have all along thought that many (obviously not all) of the people who spend mega dollars on psychotheraphy, DC adjustments, sleep aids etc that the health dollars would be far better spent on a 2 week vacation to Bonaire. Just my 2 cents worth!

Marilyn,

According to the DAN website http://dan.org/medical/faq/faq.asp?faqid=43
a spontaneous pneumothorax generally is an absolute contraindication to diving. It still might be worth having your son checked by a doc who is knowledgeable in this area, and DAN can probably refer you to someone in your area.

About the diuretics: the way they lower BP is not entirely clear but the loss of fluid, salt, etc in the urine doesn't explain it. There are MANY drugs, especially older ones, whose mode of action is unknown or only partially understood. The classic example is aspirin, used for a hundred years or so before the mechanism was fully understood.

Vince,

I just didn't want to see a bunch of people decide to skip their BP meds while diving. I agree with your larger point about unintended and unforeseen consequences.

Looking forward to lowering my own BP in 6 more weeks...

David

Marilyn,

Here http://dan.org/medical/physicians.asp is the DAN physician referral page.

I've been taking an antihypertensive with a diuretic for years, and I have never altered it while diving. I've never had a problem. I make sure I drink a lot of fluids, and it's true what they say about the "clear pee".
I've never had an issue with being hypotensive (low blood pressure) on my many dive trips.
I also go for a yearly full physical, and make sure I have an MD note that I'm fit to dive.

Thanks so much for your input David. That's what was niggling at the back of my mind. I now remember what the physicians told us when Joshua was hospitalized. I'll print it out for him. We are quite the family!! I have some left over memory loss from a brain hemorrhage 3 years ago. I know I may not dive, but I love snorkeling and swimming. It's enough for me. I too take an antihypertensive with a diuretic and have always made sure I drink a lot of fluids while on the islands.

I too share Dr. Frank's concerns about stopping a diuretic while diving. There are many reasons to be concerned about this.

I would definatly be concerned about how much higher you BP goes when off a diuretic. I know of no studies on the effects of diving on BP but I bet that the fluid loss with diving may not bring ones BP down to levels that were present before stopping the diuretic.

Another concern would be about what happens to your pottasium levels off of the diuretic. Diuretics like the one in "Avalide" (hydrochlorothiazide) tend to cause potassium losses - while the other half of that combination medication (irbesartan) tends to cause potassium retention. So combined in a combo drug they sort of offset each other. Take away the diuretic and there is the potential for elevations in blood potassium levels. It is difficult to say if this would be a clinicaly important event - much depends on what other medications you are taking and your overall health (especialy kidney function).