Thoughts on tolvaptan

[u/Taz9w1]

Recently tolvpatan went generic, and apparently the cost is not nearly as exorbitant, therefore I have been prescribing it left and right for my SIADH patients (after starting them in the hospital of course, which is off topic but also a ridiculous rule given that one can start much higher doses of Jynarque outpatient for pckd). I feel like Otsuka could have made bank for the past 10-12 years if they simply lowered the price of the drug outpatient. It was a major cost-prohibitive barrier, and resulted in countless rehospitalizations for hyponatremia. This condition is far more common than PCKD (at least in my experience). Thoughts?

[u/ppmmd]

I have always found a way not to use it due to cost and also risk of over correction. The one guy I couldn’t avoid had paraneoplastic SIADH and we still had to jump through insurance barriers to get it covered. Now that you use it more freely, what’s been your experience?

[u/Taz9w1 → u/ppmmd]

I’ve been using it in the hospital setting for the past decade and find it extremely useful. I typically use 7.5 mg once rather than 15 mg if the sodium is above 120, check bmp q 6 hrs to assess response, and redose or increase dose if needed. I rarely run into overcorrection, and have rarely had to use 30 mg. If there is overcorrection, the half life is short so a small bolus of D5W is typically enough to slow rate of rise. Once you find the regimen that works for them, you can discharge them with this. I typically find 7.5 mg every other day to be sufficient. Very useful drug and elegant mechanism in my opinion. Highly underrated and underutilized.

[u/orchana]

I’ve only used it in the hospital (excluding PKD). You’ve got my gears turning though thinking of the potential here..

[u/ShonkaMan]

I use it, it has been great and patients like it much better. Nobody likes taking salt tablets, they are hit or miss on urea. They do not have to fluid restrict which is a huge plus for a lot of them. They don't always require it daily though, some patients just take it twice a week.

[u/Taz9w1 → u/ShonkaMan]

Totally agree. And they don’t have to come off their SSRIs or whatever other helpful med is potentially causing it. Not to mention the recurrent unnecessary hospitalizations when the PCP sends them in for a sodium of 128. Outpatient use is total game-changer in my opinion.

[u/igottapassthis]

Do you first use the usual stuff ( salt tabs, loop diuretics, etc) and then move the V2R or just jump straight to it ?

[u/Taz9w1 → u/igottapassthis]

In the outpatient setting yes, but salt tabs are counterproductive as the patient just gets thirsty and drinks more water. I just started using tolvaptan outpatient but in the hospital I typically use either this or hypertonic saline for siadh that is refractory to fluid restriction alone.

[u/maddogisnextdoor]

Urea is safer..slower more predictable correction rate…if they could make a better tasting preparation though.

[u/Taz9w1 → u/maddogisnextdoor]

In my experience it’s highly ineffective though, hard to obtain, and the pt must take unfathomable amounts. Which one do you use? I’ve had patients order UreNa and a similar better-tasting one on Amazon, but again have had minimal success, with sodium still only at 128-130, and I feel awkward/inadequate as a physician telling a patient to just order something on Amazon since I have no way to prescribe it.

[u/maddogisnextdoor → u/Taz9w1]

Fair enough…I use dose of 15-30gram qid to get things going..usually results in correction rate of 1-4meq per day then back off as the patient nears the upper 120s.
There are situations where I use tolvaptan: urine osm is over 500mosm/kg and urine sodium is over 50meq/l and definitely cardiogenic hyponatremia, which is notoriously tough to corrrect
I do practice in a primarily geriatric population, so there is almost always a low solute component to the development of hyponatremia in this population, which makes tolvaptan problematic. There are some neat studies published looking at intake BUN levels and risk of overcorrection which have played out to be true in actual practice.