Pegasys stopped working

[LisaC101]

I have PV and take Pegasys 135mcg weekly for about 15 months. It had been worked really well for me with no significant side effects and blood counts were well controlled. However, about three months ago, my platelet count started to rise rapidly, from 400s to now 700s. My Dr. suggested to increase the dose to 180mcg per week. I am taking that for two weeks now, and still see platelet slightly increasing.

I am wondering what might cause Pegasys to stop working (I didn't take any new medication nor herb etc...)? I am very skinny. Will lack of body fat affects the absorption of Pegasys after some period of time ?

Not sure if anyone has experienced a similar situation. Any thoughts or advice is highly appreciated!

[Manouche]

It does not seem to have stopped working. It seems to be just less efficient at the dose you were taking. 2 weeks is too short a time to see a decrease in your platelets. It could take 3 months or more. I wouldn’t worry!

[swimswam]

Hi Lisa,

When I started normal Interferon, my platelets dropped at first, but then started to rise again. Changed to Pegasys in January 135mg, but so far my platlets have still remained 600-700. Heam. Nurse wanted me to increase to 180mg but I have asked for a telephone consultation with the Dr to discuss it first. I was interested that you seemed to have had a similar experience, and would also be interested what others have to say.

[hunter5582]

By all means pay attention to changes in your blood cell levels, but suggest not worrying too much about the platelet levels. There is no linear risk increase when your platelet levels vary. The most true measure of the status of your PV is Red Cell Mass. That is the most important thing to watch. Your HCT is a rougher estimate of your status and is used to estimate when you need to have a phlebotomy as part of your treatment (HCT>45% for males, HCT>42% for females).

Also bear in mind that it is normal for platelet levels to vary. Sometimes by as much as 100K in a day. Bleeding/venesection, inflammation, injury, infection - all can increase your platelet levels. So can iron deficiency. Understanding what is going on requires a broader look at everything. suggest an updated look at everything your entire CBC, CMP, Iron panel, etc to assess your status.

Hope that helps and you figure it out ASAP.

[LisaC101]

Thank you all for your replies. I used to have monthly blood test, and then changed to weekly to keep close watch on my platelet level. My platelet count keeps going up every week for the past few months. That's why I am concerned and worried it might go up over 1000 soon.

Though the platelet count keeps going up, my HCT remains below 42.

I will stick with Pegasys 180mcg for a little longer to see if it will bring down my platelet level, and also consult with the Dr. to have an overall look at the lab work.