Monday, December 9, 2013

I get some great letters, here is one of the best from a woman with SIADH

An e-mail I received last month:

I love your blog.  I have had SIADH for a zillion years.  I only found out what I had when I went with 5 girlfriends to a fancy spa hotel  in Tucson for a mini-vacation/ 4th of July Weekend in 1997 where the heat increased to an uncomfortable 117 degrees.

Healthcare workers in the hotel kept handing out bottles of water at each hotel exercise location with orders to “hydrate, hydrate, hydrate” and I stupidly followed their directions.  I drank myself into a 6 day coma.
The only time that sentence has been used for water, not alcohol.
Very non-traumatic for me. Very traumatic for my family. I woke up on day 6 saying, “I am STARVING!  Will someone go get me a taco?” which was very anxiety-relieving for all of them; they’d been sure I’d wake up cognitively impaired.  I wasn’t.  This “taco” sentence sounded JUST like me.  And I have continued to be not cognitively impaired despite interesting lab numbers.

My dad (who is a physician too) has SIADH as well, though his was diagnosed after mine.  I was mis-diagnosed for 9 years prior to my coma as having a “seizure disorder.”  The excellent care I received when my mental status went to heck in a handbasket was truly life-saving.  I remain a very grateful nephrology patient.  And I really do love your blog.
Thought you should know this.

She wrote back a few days later giving me permission to post her letter:

I am dying (well not literally dying) to start an SIADH group on Facebook.  We are so not connected to one another, and each of our nephrologists only have a handful of patients and of course the doctors can't introduce us to eachother because of HIPAA. 
  • For those of us that have the Syndrome without lung cancer and so on and have to live our lives thirsty
  • and our summers avoiding the sun through our sunroofs (Demeclocycline)
  • and have to, if we're female, find inventive ways to paint our nails to avoid Demeclocycline making our nailbeds ugly colors
  • and have to fear that Otsuka Pharmaceutical will convince the ONE manufacturer who makes Demeclocycline to stop making it and force us into buying Tolvaptan even though they never tested it in 3rd stage human trials on people that weren't already cognitively impaired (I know because I volunteered for every single US trial), 
Well, we NEED each other.  We need tips on nail polish, tips on drinking our fluids out of 1 ounce shot glasses, tips on rolling ice cubes around our mouths during the days our sodium is tanking, and your website is a GREAT place for us to meet up!  

You have my non-dying thanks and permission to reprint/repost any or all of my statements!


The best story that wasn't nominated.

Its oscar season in nephrology. The RFN is winnowing down the top stories in nephrology of 2013 but maybe the most important isn't even nominated. It came out too late. On November 27, Kidney International released this study in advance of print:


The bullet point I learned in fellowship was that the rate of renal failure in kidney donors was no higher than the general public, of course the kidney donors are screened to be much healthier than the general public, so the fact that the rate of renal failure is not significantly lower than the general public is an important signal.

Have I mentioned how
much I love MedCalc?
Donors don't have obesity, diabetes, hypertension. Of course most of them also have family history of kidney disease, so when they do develop kidney failure attributing the cause cause can be tricky, certainly some of these people would progress to renal failure even if they didn't donate.

Into this statistical Gordian knot wades the Norwegians.
  • 15 years of follow up for donors that were 46 years old at the time of donation. That is adequate follow-up in my mind.
  • Their center had no preoperative mortality. They did 2,269 living donations with out losing a donor. Great work by the surgical team.
  • They found an increased risk of death by any cause, HR 2.49 (CI 2.13-2.91). 
  • Adjusted HR for all-cause mortality fell to 1.48 (CI 1.17-1.88). 
  • I used their raw mortality data to calculate the Number Needed to Harm. It was a frightening 23 (4.3% absolute risk increase). I do not think this is a valid use of NNH, see below.
  • The CV Mortality HR was 1.4 (CI 1.03-1.91).
  • ESRD was increased from 0.01% per year to 0.03% a relative risk of 3 but a number needed to harm of 5000. (i.e. you would have to do 5,000 living transplants a year to see one additional cases of dialysis in a donor)
The lines only begin to separate after 10 years. This indicates that we should probably ignore studies with less than a decade of follow-up

The data is eye opening, but I would really be interested in seeing what the difference between first degree relatives and people not related. I think much of the increased danger comes from being related to the patient who needed the transplant in the first place.

I also recommend ignoring all the unadjusted data (including the number needed to harm) because the control group was nearly a decade younger than the donors. A ten year difference in age when the total follow-up is only 16 years makes the unadjusted data deceptive, IMHO.

I would love to see a study where the control group was made up of other people who were evaluated and cleared to donate a kidney but ended up deferring, due to the recipient getting another organ or dying or going off the list for some other reason. That would be the ideal control population.

The reality is that people want to donate a kidney to their loved ones. Telling them there maybe a small increase risk of death when you are in your late 50's or early sixty's. Will probably not eliminate many close relatives, but altruistic donors and family members should be aware of the risks as understood today. It is probably time to bury the old line about "No increased risk of renal failure than the general public."

Another study on this from 2010 can be read here.

Wednesday, December 4, 2013

Add to the list of top stories of 2013

In my manifesto on Tolvaptan, I mentioned there was another breakthrough that should be on the list of top stories of 2013, and it is...The gathering momentum of renal denervation for hypertension. This feels like it is rapidly maturing and will be a viable option in the near future.

The latest data presented at American Heart Association looks promising.

Go to Renal Fellow Network. Vote for your favorite!

Sunday, December 1, 2013

Go #TeamTolvaptan

This is just a picture of the ballot
go to RFN to cast you ballot.
One of my favorite end-of-the-year traditions is Renal Fellow Network's top nephrology stories of the year. Make sure you vote. The authors did a great job selecting 2013's top stories of nephrology somehow they forgot the Omontys allergic reaction, voluntary recall and abandonment of peginesatide.

(I thought of one more but it escapes me, I'll update this post when I remember it.)

Looking over the list, I think the story of the year is Tolvaptan's failure to FDA gain approval for ADPKD. If Tolvaptan gains FDA approval in the next year or two following re-submission this story will quickly be forgotten. But if the future goes the other way, if Otsuka abandons tolvaptan for ADPKD and decides to remain in the limited ghetto of inpatient management of hyponatremia that would be a tragedy.

Part of what gets my blood boiling is the raging hypocrisy that the very same organization that approved:
  • Zemplar (paricalcitol)
  • Hecterol (doxercalciferol)
  • Renagel (sevelamer)
  • Renvela (sevelamer again)
  • Fosrenal (lanthium carbonate)
  • Sensipar (cinacalcet)
(all drugs that have never been shown to help a patient but merely to improve some biochemical target. Hell, even sevelamer and cinacalcet tried and failed to show reduced mortality and they remain on the market) had the gall to deny tolvaptan for ADPKD.

ADPKD slowed cyst growth and slowed the progression of kidney disease. Not just for one year but for three years! It joins ACEi/ARBs and insulin in the pantheon of drugs that can slow the progression of CKD (though bicarbonate and allopurionol are walking toward the door). Denying it was preposterous.

The other part of my rage comes from possibilities of having tolvaptan available as an outpatient option for patients. I certainly want this drug available for ADPKD but turning it from a limited duration in-patient drug to a chronic outpatient therapy will completely remake the cost structure.

The price will remain high but it will no longer be $300/pill. Let us say $1000 per month. The TEMPO trial used 120 mg per day, so a month worth would be 120 pills. That would go a long way if you were interested in using tolvaptan for aquaresis. This drug is effective at increasing urine output by a mechanism totally novel to us. We are being given control over one of the fundamental control levers of the kidney. There are only limited number of these levers:
Look it how useful the drugs are that affect these hormones. The list is full of all-stars. Tolvaptan has already been proven a winner in ADPKD and maybe useful in CHF. Tolvaptan failed a pivotal trial called EVEREST, but the drug did increase diuresis, fluid loss, and the effects were long lasting. Tolvaptan failed one trial on heart failure, but alternative patient selection or dosing regimens could turn this turkey into another critical tool for heart failure. We need to have this drug available to see where it can be useful because today we are primitives.

If the FDA approves it, the fact that it failed its first application will be quickly forgotten, but if Otsuka decides to retreat from this breakthrough and live happily ever after correcting mild asymptomatic hyponatremia nephrology will be a poorer place.
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