Weird cognitive side effects from Venofer

I had Venofer about a year ago and experienced some classic "iron flu" side effects but nothing quite like this.

Had a Venofer infusion Tuesday and it knocked me on my ass. Spent all of Wednesday sleeping pretty much. Lots of intense vivid dreams, some slight malaise but no fever.

Then yesterday I tried to go back to work and it was kind of a disaster. I basically felt like I was super stoned all day but without any of the enjoyable feelings. Zero short term memory, couldn't concentrate to save my life, making all kinds of mistakes that I wouldn't usually make, stumbling over my words when speaking. I was worried enough that I went and got my blood checked but everything was good, phosphate and other electrolytes all in the normal range, etc. I'm feeling much better today but yeah, that was a bit scary. I'm guessing my body was just using every bit of energy to process all that iron

Anyone else have side effects like this?