I have a friend who lied to me and now i like look a idiot?

My friend was On drugs tonight and i was very worried and asked her why and who she did them with. So i'll use fake names...The girl that was on drugs name with be alex and the girl who i thought got her into all this stuff will be Joann. So i messaged Joann and told her that she needed to stop getting my friend alex into all this bad stuff (and by the way i don't even know joann) but anyways so i try to be nice and tell her that drugs ruin lives and stuff and it's just not a good idea..AND then guess what happens?joanna TELLS ME THAT SHE HASN'T talked to alex IN 4 years! now i look like a idiot and i'm not one to hang with druggies but i'm trying to change this person because she really wants to be on the good side of life but she has been threw so much all her life...And that friend isn't answering any of my texts or facebook messages so she's probably embarrassed that i actually messaged the girl? So i hope she doesn't do anything stupid...I don't know i hate this drama could somebody just give me some advice :(?