Hydroxyurea: what side effects were so bad you had to stop taking it?

Hello, colran! I'm sorry you're having such a tough time.

May I ask -- for what reason are you taking HU? Did your diagnosis come only a month ago?

It took a few months for HU side effects to go away. I still have some digestive issues but they are quite manageable. I did not hallucinate, that sounds serious. I did have vision effects, and still do although they are manageable. Once my platelets started to come down, my symptoms were greatly lessened.

Hallucinations? Yikes, in 12 years participating in support groups, I have never heard of this as a side effect of hydroxyurea. "Mushy brain," yes. Possibly your dose needs to be reduced? I'm not a doc, but if I were your friend, I'd be dialing your doc right now. Let us know what happens!

@colran. If you’re having hallucinations from hydroxyurea that is a significant change in your mental health status and needs to be evaluated ASAP. I echo @nohrt4me comment about dialing your doctor right now. Don’t let another day go by please.
Before you call, jot down your symptoms. Your dosage of medication. When the symptoms started and if they’re worse during certain times of the day.
Do you have any vision changes? Are you also experiencing brain fog? Is driving a challenge for you?

I have had PV now for about a year. I am a 68 year old female. I am JAK2 positive. I am on 81mg of aspirin daily. I began Hydroxyurea 500mg daily about two months ago. On the second day, my face and ears were beet-red. By day four, I got a red pin-dot rash on both arms from the shoulders to my wrists. I had headaches and nausea. The hardest symptom was sores and ulcers in the mouth and throat, along with white patches. It was difficult to swallow. It felt like an extreme case of strep throat. My oncologist prescribed fluconazole and it gave great relief in 3-4 days. My doctor discontinued Hydroxyurea. I am now on Besremi, which is an interferon therapy. Hydroxyurea was not for me. I had to discontinue taking it eighteen days after starting it. I hope your health journey improves and you find the best drug suited to your needs.

Newly diagnosed with PV JAK2 mutation 12/12/25. Started hydrea that day and stopped 1/29/2026. My labs went really low very quickly and even for a couple weeks after stopping. I felt awful the entire time. Itch got very bad ,it was constant. Mouth ulcers very bad, had swallowing issues, like someone compared it to bad case of strep. It took a week or two after stopping to feel better. My labs for the last 2 month are "normal". Interestingly I was told it had nothing to do with hydra. I didn't believe that as hydra was the only change in my meds. Rx was magic mouth wash which helped a great deal, rinse with salt water and keep mouth clean . Definitely get in touch with your provider asap

@garyr443
My RBCs have been low well before HU but they have taken a slight downturn. My Oncologist lowered my HU to 500 mg 3 days a week from 4 but my platelets jumped from 398 to 499 in three week and my RBCs just increased slightly. I want to go back on 4 times a week but they want to wait and see. They don't want me to start iron but I am doing it anyway because I really want to get the RBCs up and the platelets down and I have no real side effects from the HU.
Please keep us informed about the results from the cranberry juice. I would love to get my RBCs up without starting a new medication that might have side effects.

@sutt9101

Thank you for sharing, sutt9101.

What you went through was awful.

I'm so glad you found Besremi!

@scienceteacher Has your hematologist recommended taking Vitamin B12 and Folic Acid? Mine put me on these two B vitamins from the start, to compensate for the low red blood cells. So, I have been taking B12 and Folic Acid daily for 12 years. If it's helping, it's only to keep my red blood cells from disappearing altogether!

@scienceteacher Will do! I'm going to be tested again on July 3 and I will know how well the cranberry juice really works with platelet count. It's been doing well for maintaining normal bloodpressure.