Bone pain in second week with Neulasta?

Cinchud

Ouch! I woke up during the night with pulsing pain in my lower back or pelvis, 6 days after my Neulasta injection. I've been feeling pretty well since my first chemo treatment, no nausea, just a little indigestion. Yesterday my white blood count was low. I guess it went to work. I took a Flexeril muscle relaxant and an ibuprofen. Today I'll try a Claritan. Why does an anti-histamine help?

SpecialK

Two things - taxol also causes bone pain so it is difficult to know which thing is causing your bone pain.  I definitely recommend taking Claritin (regular, not Claritin D).  The way Neulasta works is that it stimulates excess white cell production in the bone marrow.  The biggest bones have the most marrow, so hips, back and legs usually hurt the most.  As the white cells are being produced they cause edema, or swelling.  The antihistamine in Claritin is thought to ease the swelling and lessen the pain.  Take a 24-hour Claritin an hour prior to your Neulasta injection, with the permission of your oncologist.  Continue taking it at 24 hour intervals, for as long as you think you need it.  Also, you may have less discomfort with future injections - your bone marrow expanded for the first time with the first injection of Neulasta - kind of like a new pair of shoes might hurt when you wear them the first time.  Subsequent Neulasta injections will be working in an environment that has already previously expanded - so it is like wearing the shoes again, they are not as tight.  Here is the clinical trial for Neulasta and Claritin:

http://clinicaltrials.gov/show/NCT01311336