Sounds like it was some type of reaction. I've had quite a few IPIR's that were really bad. Bad enough where the pressure in my chest was so bad I couldn't breath well. It's hard to describe but it was not fun. On the plus side, I knew what it was and just laid there until it subsided. It took about 10 to 15 minutes to fully go away.

And, if you hit a vein, that could be the reason for your reaction as well. Any time I hit a vein I had a reaction, not always the big bad ones, but a reaction that was not typical for me. Since I don't have a lot of fat on my mid to lower thighs, I always seem to hit a vein or muscle in there and would always react. So, I stopped shooting my thighs. That took care of that.

I would let your neuro know about the reaction and if you have any more. Over time, I seemed to have more of the IPIRs and have been off C for over a year now due to such. I may be going back on it though as I do think it helped me.