I am a 72 year old male and was Diagnosed with early myelofibrosis after seeing my platelet counts over 1100 and having a bone marrow biopsy. I was put on 500mg Hydroxyurea per day and eventually increased to 1500mg per day. My platelets are now at 660 but my RBC,hemoglobin and Hematocrt levels are dropping below normal ranges.; Also my WBC is dropping. I am concerned about this . How much Hydroxy per day can I take?
Has anyone had this type of experience>?
I took 3 a day for a very long time and my mpn doctor was not worried about all my counts dropping . Just keep an eye on them make sure they dont go too low especially the hemoglobin most importantly because you don’t want to get a blood transfusion
It may be better to ask the question in a different way. Suggest that the question is "Which of the treatment options is best for my case of myelofibrosis? While HU is in common use as an off-label medication for MPNs , there are other treatment options. The JAK inhibitors are in common use and FDA approved. These include ruxolitinib , fedratinib, pacritinib, and momelotinib. As the oldest of the JAK inhibitors, RUX is often the starting point for treating MF. Note that each of the JAK inhibitors has particular strengths (e.g. momelotinib is better for MF with anemia). In addition, there may be other treatment options for you to consider.
You can compare the risks and benefits of high-dose HU with each of your other options. It is worth noting that Hydroxyurea is a "highly toxic drug with a low therapeutic index." drugs.com/monograph/hydroxy... You do need to be cautious at higher doses due to the toxicity. The maximum dose varies by individual. It is important to understand what narrow therapeutic index means. Per the FDA "Narrow therapeutic index (NTI) drugs are drugs where small differences in dose or blood concentration may lead to serious therapeutic failures and/or adverse drug reactions that are life-threatening or result in persistent or significant disability or incapacity." fda.gov/media/162779/downlo.... This is an issue to review with your hematologist to understand how it applies to your case.
Comparing your current treatment plan with HU to your other options is something that needs expert guidance. Hopefully, you already have a MPN specialist on your care team rather than a regular hematologist. If not, this would be a good time to seek a second opinion. Here are two lists just in case you need them.
pvreporter.com/mpn-speciali...
After reviewing all of the available options, you will be able to decide whether HU is the best option or if another medication would be more suitable. You will need to be clear about your treatment goals, risk tolerance and treatment preference. You are the only one who can make this decision.
Wishing you all the best as you move forward.
I can only suggest you see an MPN specialist. 1500 mg HU is a very strong dose.
Best wishes.
Hydroxyurea 
hydroxyurea & anger
Starting Hydroxyurea 
