I have received IVIG on/off (mostly on) since 1997. I currently (for the last 2 years) receive a dose for both my immune deficiency and neuropathy.

Side-effects are different for everyone and can even change with each infusion. It's a blood product (comprised of up to 2000 donors per dose), so you can react differently each time. But, by in large, people experience at least a few side-effects with each dose. Headache and flu like symptoms are probably at the top of the list. I have some headache with each infusion, but it's far less then I used to get. I also get weak for a couple days. During the infusion, I get chills sometimes, and my BP drops...both of which are somewhat common. I have also had a severe case of aseptic meningitis from IVIG (in 2007)...so bad that my white cell count in the spinal fluid was over 700 (normal is under 10) and I was hospitalized for a week with full recovery taking over a month. I had to stop infusions for several years. This reaction happened after receiving IVIG for 10 YEARS. Don't think that having received IVIG for a long time means you get used to it and won't have bad reactions...it's just not true and anyone can have unusual reactions after years of therapy. I don't mean to scare you, but it's important to know that with blood products, each infusion is a NEW experience and anything can happen.

Pre-medications are import to help avert the side-effects. Most common are Tylenol, Benadryl, and IV steroids. I use all three of these plus Zyrtec. Actually, it was the addition of Zyrtec that greatly reduced my headaches and chills, and completely stopped the burning lips/mouth I would get on day 2 or 3 after the infusion. I take the pre-meds right before the infusion except the Zyrtec, which I take the day before, day of, and for 2-3 days after the infusion. I can't say enough about how the Zyrtec has improved my IVIG experience each month.

The other thing that is VERY important to keep side-effects at bay is hydration. I drink plenty of water & Gatorade or pure Coconut water (which is FAR better for hydration than either water or Gatorade) before, during and after the infusion.

IVIG works by modulating the immune system, but the actual mechanism of action for it's affect on neuropathy is unknown. There is assumption that it goes after the errant antibodies that are attacking the nerve endings. So your description of a war going on inside, isn't far fetched. And it's this war of antibodies that create your side-effects.

What type of side-effects are your experiencing? Are they showing up during the infusion or 2-3 days after? What are your pre-meds?