Hello, I Have A Potentially Serious Health Concern Regarding My

Hello, I have a potentially serious health concern regarding my brother. He has authorized me to give this information, as he is very concerned as well. Recently, my brother has been injecting the sublingual medication Suboxone into his veins through his arm after melting it down. He is now experiencing intense pain in his neck on both sides. There seems to be several knots, both small and large, in and around the vein area of his neck. They do not seem to be in the muscular area and do not feel at all like muscular knots. Could you please provide me with information at to what this could be? Also, is this as dangerous of a situation as it seems to me? Thank you.