Any thoughts?

My husband is a drug addict and he has a problem with painkillers. We are no longer living together currently and I have filed for a divorce. It's a long story but he was hiding his drug use form me for a very long time. He would hide stuff in our attic. Recently, I was up there and I came across a small bottle of liquid lidocaine and a package of hypodermic needles. Do you know what he could have been with this.. it doesn't look like an RX, as there isn't anything on the bottle. I am very naive to this stuff so please explain