Tolvaptan tales: Four years on

It has been four years since I started taking tolvaptan for my kidneys and I thought it was time for another update – especially as the last one was a two-year review. Although it’s fair to say that anything I shared in a three-year review would have been quite like this review. (Which is a bit different from life after the first and second years.)

Part of the reason I am sharing this four-year update is that I’ve had a few people ask about how things are now. However, it is primarily for my own personal reflections as a future memory prompt. That said, I hope that it will serve as an information starting point for others. Please note that your experiences may vary.

For my other tolvaptan updates, check out these posts:
Talkin’ tolvaptan (A layperson’s explanation of tolvaptan)
Tolvaptan tales: The beginning (My first month’s experiences)
Tolvaptan tales: A four-month reflection
Tolvaptan tales: A one-year review
Tolvaptan tales: Two years later
Tolvaptan tales: Four years on
A generic tolvaptan update (A six-year review)

Disclaimer: I am not a medical professional, nor do I have any professional health or fitness qualifications. This post is about my own experiences with taking tolvaptan for PKD. It is meant as an informational starting point – not as medical advice. Please consult your medical team if you have any questions or concerns about your own health.

Warning: This is a very long post. However, it is organised into sections to help you find what you’re looking for. You can jump straight to a section by clicking any of these hyperlinks:

• What is tolvaptan?
• Regular blood work and liver tests
• Timing of pills (including skipping pills)
• Hydration and urination
• Sleeping through the night
• Alcohol consumption
• Reflective review

What is tolvaptan?

Tolvaptan is a selective vasopressin V2-receptor antagonist. This basically means that it reduces the level of the hormone that regulates the balance of water and sodium in your body by increasing fluid excretion (Reference 1; Reference 2). 

Tolvaptan is the first drug licensed to slow the progression of autosomal dominant polycystic kidney disease (PKD). In trials, tolvaptan was shown to slow the growth of the cysts and to slow down the loss of kidney function by about 30%. That means that someone “on track” for kidney failure in 15 years will have about 20 years instead. (Your mileage may vary!)

There are three standard doses, split into two pills: 45mg/15mg (low dose), 60mg/30mg (middle dose), and 90mg/30mg (high dose). The larger pill is taken in the morning and the smaller one is taken 8 hours later. Generally, you start on the lowest dose (45/15) and the dose is increased to the middle then the high dose as you grow accustomed to the side effects.

My dosage: I have been on the top dose of tolvaptan for most of these past four years, having moved up quite quickly in the first six weeks of taking the drug. That means I take 90mg in the morning and 30mg in the afternoon.

Regular blood work and liver tests

Taking tolvaptan requires regular monitoring to check on liver function and eGFR. I outlined this in more detail on my four-month review under “monthly lab work and liver tests”. Now that I am four years in, my lab work is only done quarterly.

eGFR (kidney function, ish): I am pleased to say that my eGFR has been decent. In the two years, my overall levels have dipped a bit, but I am still at 50+ on most of my readings (sometimes in the high-50s). At my last face-to-face review, my nephrologist calculated that, at my current rate of decline*, I have about 15 years before I will need to start thinking about the next steps (dialysis and/or transplant). I will be in my early-60s by then and I find that acceptable, given my family history of earlier decline.

A note on eGFR: the “e” stands for estimated! Many factors can cause a dip in the numbers and that doesn’t necessarily mean a decline in kidney function. Try not to worry if you get a seemingly low reading as it could be a fluke. It is more important to look at trends over time. If you are concerned, speak to your doctor about your individual status.

Liver tests: All my liver test values have been within the normal range, save for a one-time blip in my first four months on the drug. I am pleased with this, although I am sometimes worried about the future of my PKD-L liver even though there is no immediate medical cause for concern. But I limit/monitor my alcohol consumption, just in case!

Other values: The rest of my lab values are as to be expected, although I am starting to pay more attention to my blood pressure these days. It is not affected by tolvaptan, but as any PKDer knows, blood pressure is important. Currently, I am can still manage mine without medication (I average 118/76). I have wondered if the increased hydration from tolvaptan has helped me to manage it better, but there is no “real” evidence to back that up.

Timing of pills

Tolvaptan is taken twice per day. The first dose is taken in the morning and the second is taken about eight (8) hours later. I take my first dose by 6 am most days and my second dose at 2 pm. As I explained in my two-year review, I set my morning pill out in the kitchen the night before with a bottle of tap water. My alarm clock is set for 5.30 am and when it goes off, I get out of bed to walk to the kitchen for my pill. I also start making my morning coffee at this point and doing my morning stretches. However, on occasion, I will hit snooze a time or five and won’t take my first pill for another 30-60 minutes.

My afternoon pill is (almost) always at 2 pm, even if I’ve taken the morning pill slightly earlier or later. This way I do not have to re-set my alarm each day based on the morning timings. However, if I am out running, hiking, or [enter other activity here] I might delay the pill by an hour or so. This is because I don’t carry them with me unless I am intending to be out well past my normal time.

Skipping pills: Over the years, I have found that it is best to skip my pills on occasion. The reasons I skip the pills vary. For example, if I am going out with friends and know I will be drinking (too much) wine, taking a long flight, or going on a long adventure walk in the wilderness. Or maybe I just need to feel normal for a few days.

Sometimes I just skip the morning or afternoon pill. For example, if I am going to be running a marathon (or a half marathon on a hot day) I will forgo the morning pill so that I don’t risk dehydration. Likewise, I will skip an afternoon pill if I am away from home and unsure about how/where I will manage my hydration or urination needs. In fact, some doctors also recommend taking breaks when you’re on holiday – especially if you’re going somewhere hot. Be sure to discuss this with your doctor though!

I am not advocating for a willy-nilly pill-taking routine. But it is possible to miss out on a few pills when you need to. There are no side effects from skipping tolvaptan on occasion, but remember that the longer you take it, and the more regularly you take it, the better your overall outcomes of the drug will be.

Hydration and urination

Hydration: The most noticeable side effects of tolvaptan are related to thirst and the subsequent need to urinate. It took about a year to fully settle into a good hydration routine, and I have mostly stuck with it since then. My routine relies heavily on the practice of “front-loading” my fluid intake. By that, I mean that I drink the bulk of my fluids earlier in the day so that I am well-hydrated by evening time.

A typical day’s hydration routine starts at 5.30-6.00 am when I take my first dose with several big gulps of water. I then enjoy a mug of (very) strong black coffee as part of my relaxing morning routine. The post-coffee routine has varied a bit over the last year because I’ve been working from home.

Pre-pandemic, I enjoyed a large glass of fresh, crisp water before heading into the office. Once at my office, I made a large pot of peppermint tea (50 ounces) and filled my 24-ounce water bottle. Both would be consumed before lunch.

During the pandemic (i.e., working from home), I make my peppermint tea at the same time as my morning coffee. I generally drink that before I walk into my home office for a 9 am start, taking a 24-ounce water bottle with me.

In both cases, I drink a couple of 24-ounce (reusable) bottles of water before lunch. Then in the afternoon and evening, I will enjoy another 2-4 bottles (on average). By then, assuming I’ve “front-loaded” well, I don’t feel very thirsty and can take just a few sips here and there. (Note: This process helps with sleep, as outlined below.)

Most of my fluid intake is water and peppermint tea. However, I also eat a lot of fresh fruit and vegetables and other “hydrating” foods which adds to my fluid intake. I also drink a glass of (watered down) fruit juice or a fizzy soda on occasion – and sometimes I enjoy an ice lolly or popsicle to quench my thirst. (And yes, a bit of booze, as I will address below.)

All told, I drink between 4-6 litres (150-200 ounces) of fluid on a typical day. That might increase on hotter days or if I am running 10+ miles. It will also vary based on the kind of food I am eating, as noted above. A saltier diet means more fluids; more fresh foods and brothy soups mean less fluids.

Urination: Of course, when you’re drinking 4-6 litres of fluid every day, you will be making more than a “typical” number of trips to the toilet. But even that improves the longer you are on the medication.

For me, because I drink so much fluid in the first 5-6 hours after I wake up, I need to urinate a little more often earlier in the day. I go to the toilet about every 2 hours before 2 pm then about every 3 hours after that. My bladder is generally happy to go more than 2 hours if needed, but when I get up to refill my water, I will generally go for a quick pee, too.

When I am away from home, I can make my time between toilet breaks stretch out a bit by sipping fluids instead of guzzling, as I do when I’m “front-loading”. I have also found that I can manage a good 4-6 hour walk in the hills without being desperate for a pee – but only if I am careful about how I hydrate ahead of time, and I must go right before leaving the cottage. (I was raised in the mountains though, so I am more than willing and able to pee outdoors if necessary!)

Oh! And in pre-pandemic times, I would take any chance at using a public loo when I was away from home. Better to go when you have the facilities than to get caught out with nowhere to go! Living in a cosmopolitan capital city means that I have a variety of coffee shops to pop into if needed when they’re not closed for COVID19, that is.

Note: The need to urinate when taking tolvaptan isn’t an immediate “must go now” sensation for most people. This means that you are unlikely to be in a position where you have an immediate urge to find a toilet so don’t worry about being caught out unaware. The frequency of peeing will largely depend on your fluid intake. But for comfort’s sake, don’t wait too long between trips to the loo!

To segue into the next section, the primary reason I started to front-load my fluids was so that my thirst would decrease in the evenings. By only sipping water in “normal person” quantities, I can generally manage a solid 6-8 hours of uninterrupted sleep each night before my bladder decides it’s time to go!

Sleeping through the night

In my first year of taking tolvaptan, I was constantly changing my routines so that I could find a way to get as much uninterrupted sleep as possible. At that time, I mostly managed to sleep through until almost 4 am before my bladder woke me. Then, by my two-year reflection, I could generally manage 6-8 hours of uninterrupted sleep.

Since then, I have settled into a good pattern resulting in a weekly average of just over 7 hours’ sleep each night. I have also come to learn that I function best on less than 8 hours’ sleep (but ideally more than 6.5 hours). This means that I am less concerned with a strict 10 pm bedtime – but I am rarely in bed later than 11 pm.

Once in bed, I can almost always sleep through to my 5.30 alarm – assuming I got my hydration right earlier in the day! In fact, it was harnessing the earlier waking times as an energetic jumpstart to my day that made me realise I’d been caught up in the 8-hour myth* for too long. (Who knew that productivity could be an unintended side effect of tolvaptan?)

Alcohol and tolvaptan

I wrote about drinking and tolvaptan in my four-month review and have noticed that my tolerance has changed since then. When I first started taking tolvaptan, even one glass of wine could cause me to feel very dehydrated the following day – as if I’d had a bottle of the stuff! Over time, however, I have found that one or two drinks don’t really make a difference. I think that is because I am better hydrated overall and because I have learned to drink extra water if I know I’m going to have a drink.

Because I like the idea of a drink, but not of getting drunk, I have started to change the way I make cocktails at home. Some cocktails are always going to be stronger than others, but those that rely on fruit juice can be made weaker by adding twice the juice. I have also started to include a couple of ice cubes in cocktails so that they can slowly melt making the drink last longer. Likewise, if I am drinking something like prosecco, I have started to fill the glass with ice cubes made from cherry or pomegranate juice before pouring the fizz. This way I can enjoy a slow-sipping fizzy drink with half the booze. And then I can enjoy the luxury of a second glass whilst only having one glass. However, I am sure you’re not here for mixology tips, so I’ll move on …

There is no reason that you must avoid alcohol just because of tolvaptan. However, you may find that your tolerance to it might change, and change again, over time. But, as with anything medical- and health-related, you should do what’s best for you after consultation with your medical team.

The reflective bit

A lot has changed in the four years since I started taking tolvaptan and the biggest change is how “normal” taking tolvaptan has become – especially in the last two years. This is the first time I’ve taken medications long-term, so it was a struggle to fit it into my routine at first. But because I wanted to take the first dose as early as possible each day, I experimented with how best to fit it into my morning routine. I have now developed a solid routine that I can’t see it changing much moving forward, except for some minor tweaks related to “COVID life” – especially when I start to rejoin society after a year+ of isolation.

What hasn’t changed, however, is the ongoing questions I have about if the medication is actually working. There are no real indicators to know if tolvaptan is slowing down the progression of my kidney disease. Yes, the research shows that, on average, the drug can slow things down by about 30%. But that is based on statistical models that consider large datasets and there really isn’t a way to test things at the individual level. That is because we don’t know someone’s actual rate of progression is/was, so we can’t know for certain if it’s slowed and by how much.

If I am in the average range, then 30% over the course of four years is a little over 14 months of extra time for my kidneys. But it’s also possible that I’ve not received any meaningful benefit and that the projected 15 years (see intro above) is the best I can hope for at this time***. I am trying to be hopeful, but I also know that anything can happen!

After four years, I feel happy and confident about taking tolvaptan (mostly). I still feel a bit guilty about using up all these precious medical resources (tolvaptan is not cheap!) but I am trying to get over those feelings. Most importantly though, I feel a bit of hope that there will be even better treatments (and maybe even a cure) for future generations.

If you have any questions or comments, please feel free to reach out in the comments below or if you’d prefer, you may contact me privately.

Disclaimer: I am not a medical professional, nor do I have any professional health or fitness qualifications. This post is about my own experiences with taking tolvaptan for PKD. It is meant as an informational starting point – not as medical advice. Please consult your medical team if you have any questions or concerns about your own health.

* I recognise that this can change at any time. That is why I do my best to balance a healthy diet and exercise/fitness routine with living a fun and enjoyable life.
** Well, it’s not completely a myth. But most sleep researchers suggest it’s a range of 7-9 hours for adults. I just tend to fall on the low end of the spectrum for optimum function.
*** To clarify: That is 15 years to end-stage kidney failure and the need for dialysis and/or transplant. It is not the end-stage of life!