Over many years I've had many different medications for PKD, as my eGFR slowly declined and my blood pressure rose. Recently, I came across a new medication called Empagliflozin, that was developed for diabetic patients but was more recently found not only to reduce blood pressure, but actually improve kidney function.
For the past 18 months my BP has been seriously high and no medications has reduced it. So I asked my GP about trying Empagliflozin, but she said it was only for diabetes; a couple of weeks later - having evidently done her own research - she gave me a prescription, and it has reduced my BP quite significantly. There are quite a lot of potential side effects but after several weeks, so far so good.