Opioids Missing the injection

My friend recently shot up 100 mg pill of Kadian. She missed the shot and even though it didn't hurt right away, it started to swell up pretty bad. Now it looks and feel like there are hard lumps in her arm where she missed. She has missed a shot before (from other substances) but it's never been this bad. There is a pretty painful lump in her arm and her skin is red in that area plus there is some swelling. Could this be anything serious? She says its very painful to fully extend her arm and she normally stands with her arm slightly bent now. She missed her shot of kadian about 4 days ago but she is still in a lot of pain. But it's definitely managable and she hasn't taken any opiates or even over-the-counter pain relievers such as ibprofren. So it's not an unbearable amount of pain. But I am worried about her and worry it could be more serious. I also know that slamming kadian would be much harder of a miss than the big H, so maybe this lump will go away in a few more days?

If it hasn't gotten any better since it was at it's worse I would seek for some attention and care.

I do not know if a missed shot of morph. would take longer to subside as compared to a missed shot of diamorph. But 4 days seems too much.

Yeah, 4 days is too long. You may need to see a doctor.

Go directly to the fucking ER before she/you gets sepsis. Fuckin serious. Go to the ER.