I can't say how much I got in the hospital over the 3 day period (my initial loading dose of IVIG).. but now I get 50g every 2 weeks (and I weigh 60kg).. so that's almost 1mg/kg during just one day... not sure if this qualifies as high dosage or not.. Other people at the infusion center get 100g in only a few hours .... I have to go at a slow rate or else I get side effects- chest pain, headaches and aseptic meningitis.. so I can't go above 100mg/hour .... I drink TONS of water the night before and up until 24 hours afterwards or so... that also helps!!
Good luck!!

(interesting about the IgA deficiency.. how did they diagnose or find that? They have wondered if I had that, but didn't check it till after I was on IVIG.. I have never mounted antibodies/titers to vaccines or illnesses that I have had.. they would check and it would be negative, and we would have to re vaccinate me etc.. my father has the same issue.. )