I have Poycythemia vera, diagnosed five years ago, initially treated with phlebotomy alone. For two years I have been taking Hydrea also, and now discover from creatinine clearance rate that I have moderate renal insufficiency. I see this is a possible side-effect of Hydrea: should I stop taking it? It doesn't control my haematocrit, for which I have phlebotomy, currently a well-controlled 44%, and also take Aspirin daily, so am not sure how important the Hydrea is for me. If I can do without it, I think I should. I will discuss with my haematologist next month, but am inclined to gradually reduce the dose to nil to see what is effect it has on my blood analysis. Any views?