1. Why do I need to have blood tests before I start taking this medication?
3. How often do I need to follow up with my doctor while taking this medication?
4. What happens if I miss a dose of this medication?
5. Are there any dietary restrictions while taking this medication?
2. Where can I get this medication?
9. Will I have to take these medications forever?
8. Will I be able to afford this medication?
7. JAK inhibitors are still pretty new – are you sure they’re safe?
6. I read that JAK inhibitors increase the risk of blood clots. Should I be worried?
5. Can taking a JAK inhibitor cause cancer?
4. Why do I need to get certain vaccinations first?
3. Will taking a JAK inhibitor shut down my immune system?
2. If one JAK inhibitor doesn’t help me, does that mean none of them will?
1. Which JAK inhibitor is most likely to help me?
FAQs About VRAs for ADPKD, Answered
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6. Are there risks associated with this medication?
7. Will I have to take this medication forever?
8. What happens if this medication doesn’t help me?
Blood tests are used to evaluate your risk for kidney function loss over time. There are at least a couple of tests that your doctor may order, according to Hallows. These include your eGFR (estimated glomerular filtration rate), a measure of kidney function based on your blood level of creatinine. Your doctor may also order a genetic test to find out what kind of mutation is causing your ADPKD, which can help predict loss of kidney function. You’ll also need blood tests to assess liver function before starting tolvaptan, as well as while you’re taking the drug.
You can only get tolvaptan through a pharmacy that is enrolled in an REMS program through the FDA, and most pharmacies don’t do this, Anand notes. Your doctor will let you know how you can get this drug if you decide to start it.
You’ll need to get regular liver function tests while taking tolvaptan, and you won’t be able to get a refill of your medication unless you’re up to date on these tests. You’ll be tested 2 and 4 weeks after starting tolvaptan, then every month for the first 18 months, and then every 3 months for as long as you take the drug. Your doctor may decide to reduce your dose or stop the therapy based on these results at any time, Anand notes.
According to the drug’s manufacturer, if you miss a dose of tolvaptan, you should skip that dose and take your next dose at the scheduled time.
According to the drug’s manufacturer, you shouldn’t drink grapefruit juice while on tolvaptan, as it can increase blood levels of the drug.
Reduced liver function is the main risk associated with tolvaptan. This is why you’ll need to have regular liver function tests. Another potential risk is if you’re incapacitated due to an accident or another health problem and unable to drink water, you may develop a blood chemistry imbalance. “Your loved ones should know you’re on this medication and you need water, if you are not able to speak for yourself,” says Anand.
Generally, if you can tolerate tolvaptan, you’ll take the drug for years to help delay the onset of kidney failure, according to Anand. “When people are starting dialysis or need a kidney transplant, that’s when we may stop it,” she says.
It can sometimes be difficult to figure out if tolvaptan is helping preserve your kidney function, especially right away. In any case, you shouldn’t expect the drug to completely stop your loss of kidney function. “In people whose kidney function was declining fast, I’ve seen it start to decline more slowly,” says Anand. If, over time, you and your doctor truly find you are not benefiting from the tolvaptan, you’ll need to discuss whether you should continue taking it. Additionally, if you can’t tolerate tolvaptan because of reduced liver function or increased thirst and frequent urination, you and your doctor may decide that you should stop the drug.
