I have gotten my platelets down to 388,000 but it has take a long time and it has been all over the chart. When I was first diagnosed, they were 1,250,000 I was first prescribed 2,500 mg of HYDREA daily and gradually the dosis was lowered. We have found a pretty stable dosage of 1,000 mg daily x 7 plus one week I add 1,000 (2 500 mg tabs) and the next I add 1,500 mg. My oncologist feels that if I can keep my platelets below 500,000 I am doing well. Of course, I prefer them closer to 400,000. But I also have to watch my red blood cells and white blood cells which are a little on the low side right now.
I take an 81 mg aspirin every evening. I looked at ANAGRALIDE. My first doctor had mentioned it as a possibility if the Hydrea needed something more. but so far I have had success with the Hydrea plus the baby aspirin.
I read this interesting article recently about ANAGRALIDE on PUBMED.GOV website:

Hydroxyurea compared with anagrelide in high-risk essential thrombocythemia
Abstract
Background: We conducted a randomized comparison of hydroxyurea with anagrelide in the treatment of essential thrombocythemia.

Methods: A total of 809 patients with essential thrombocythemia who were at high risk for vascular events received low-dose aspirin plus either anagrelide or hydroxyurea. The composite primary end point was the actuarial risk of arterial thrombosis (myocardial infarction, unstable angina, cerebrovascular accident, transient ischemic attack, or peripheral arterial thrombosis), venous thrombosis (deep-vein thrombosis, splanchnic-vein thrombosis, or pulmonary embolism), serious hemorrhage, or death from thrombotic or hemorrhagic causes.

Results: After a median follow-up of 39 months, patients in the anagrelide group were significantly more likely than those in the hydroxyurea group to have reached the primary end point (odds ratio, 1.57; 95 percent confidence interval, 1.04 to 2.37; P=0.03). As compared with hydroxyurea plus aspirin, anagrelide plus aspirin was associated with increased rates of arterial thrombosis (P=0.004), serious hemorrhage (P=0.008), and transformation to myelofibrosis (P=0.01) but with a decreased rate of venous thromboembolism (P=0.006). Patients receiving anagrelide were more likely to withdraw from their assigned treatment (P<0.001). Equivalent long-term control of the platelet count was achieved in both groups.

Conclusions: Hydroxyurea plus low-dose aspirin is superior to anagrelide plus low-dose aspirin for patients with essential thrombocythemia at high risk for vascular events.
Hydroxyurea plus low-dose aspirin is superior to anagrelide plus low-dose aspirin for patients with essential thrombocythemia at high risk for vascular events.

I guess if I have a future problem with Hydroxyurea, the doctor would put me on ANAGRALIDE. Would very much like to keep in touch in this regard. I don't think you mentioned your age. Or I didn't see it. I am 72. Was 65 when first diagnosed.