What are most common side effects when starting HU (Hydroxyurea)?

Hi @irishnanny3 ,
I wear sunscreen and a wide brimmed hat daily and have been for years. I haven’t even taken Hydrea ever, and I have had four basal cell carcinomas removed, numerous actinic keratoses frozen with liquid nitrogen, and just recently a skin biopsy on my face on my side of cheek came back as melanoma insitu and I had a slow Moh’s started. I was not told it would not be removed in one day so that was disappointing yesterday. Anyway, with all the skin issues I have had already, I choose not to take Hydrea as I feel just fine, no symptoms, no heart issues, no clots, not overweight, and exercise daily. Also, my oncologist/hemotologist did not seem to know if I have essential thrombocytosis or primary myelofibrosis. I will have a new insurance starting January 1 which I am hoping will be better. Also, I have CALR1 mutation.

I am 59, male, oficially diagnosed with PV w/Jak2 November 2024. Phlebotomies every week until I got my hematocrit down from 68 to below 45. Then went to every 2 weeks then 3 weeks. In late March I was put on HU, 500 mg per day. in April/May (2025) acturally went 7 weeks w/o phlebotomy. Then it settled back to every 3 to 4 weeks. Upped the dosage to 500mg/1000mg every other day. Then to 1000mg every day, that made the phlebotomy remain consistant at every 4 weeks. November 2025 have now upped HU to 1000mg/1500mg every other day. Still consistantly crossing over 45 on the Hemotocrit about every 30 days.
Side effects: Hair has thinned a little, nothing major. No itching (I do put lotion on every morning). Brown spots come and go, Mayo had me do the whole dermatology exam to establish a baseline, when I was first put on HU. Have to be examined once per year they say. The spots appear for a few days on legs ( 4 so far) but then vanish. That only started in the last 2 months. I stay out of the sun as much as possible and keep arms and legs covered. It appears that PV really can effect people differently. If it wasn't for the incredibly annoying FATIGUE (yes, I cheat and drink 24 ounces, of coffee M-F (265 mg of caffiene) so I can get through the work day). My Hemotologist wants me to stay under 200 mg daily. Possibly a little bit of brain fog is creeping in, but I don't want to think about that being 3 to 5 years from retirement. Has made me more dependent on note taking and documentation at work.

@nohrt4me
How is your immune system? I am a preschool teacher so I need a good immune system. I am 63 and told I need to be on it for life from +jax2

@dragonflylynda Something you should prob ask your doc about because it varies a lot by individual.

My immune system has never been good, but flu shots kept me from getting sick when I was teaching college and working one-on-one with students in the tutoring center. (I retired at 63, 71 now.)

Little kids are very germy. My husband brought home something from his kids program at the library last January. He was over it in a few days. Mine hung on for two weeks. Not covid or flu. Just godawful cough and congestion with shivers.

He decided not to do programs for small children during flu season.

Thank you for your support on this, scary pill😊

@grandpamaui, welcome. I appreciate reading your diagnosis and treatment story thus far. Fatigue is annoying to say the least and not very understood by those who don't experience it. The whole world is walking around sleep-deprived, but fatigue is different. It's like you're walking around in a fog wearing diving gear from the 1950s. It's not a bad practice to rely on notetaking and documentation at work. Do you find your colleagues are understanding?

@colleenyoung

@colleenyoung Best description of fatigue I've read! Thanks.