can shooting suboxone cause swelling without missing

[sls.dal]

I have shot suboxone on and off for a few years. All together I've been an iv user for going on 8 years now, got on suboxone to come off of opiates. This isn't the first time I've had this problem it's just been a long time. Because of all my drug use I really don't have any veins so I had been using the ones in my neck but it's gotten to the point where I can't even use those anymore. I finally found a few veins in my hands and fingers I've been using. The last few times I've done it it has burnt extremely bad but I know I'm not missing because I pull back several times just to be sure I'm still in the vein and every time I get blood but it still burns and now it has caused my hands to swell and hurt. Does anybody know why?