A daily dose of 1500 mg Hydroxyurea seems pretty high. I would suggest a consult with an MPN specialist.
Best wishes, Eileen

Dad (who also had ET) was on both HU and anagrelide for a time in his 70s. His platelets were stubbornly high, and he had developed DVT (clots) in his legs.

I think that nowadays, docs might be inclined to try alternatives like Pegasys or Jakafi instead of increasing the older drugs, assuming that you can afford the co-pay.

It might also be a good time to get a second opinion on where you are with disease progression.

When first diagnosed 20+ years ago, m y platelets were around 1800....no symptoms, caught in a thorough blood workup. My GP sent me to a oncology hemotologist, who put me on Agrylin (anagrelide before it was generic). I never had any problem with it, as long as I take the dosage regularly (.5 mg morning and night currently). When that doctor retired ten years in, the next, new doc the Regal/Lakeside group referred terrorized me for about 2 months insisting I should have taken hydroxyurea....Finally got different authorization with Dr who said, if it works, bhy change? That's my experience!! Platelets hover below 400, see the doc every 6 months now (I'm 73), was seeing him annually in my my 60s.