Hi! Our Son Has An Ongoing Infection On His Arm

hi! our son has an ongoing infection on his arm that has been going on for over a year that was cause by a shot of heroin that failed to hit its mark.it resembles a flesh eating bacteria it has never healed even after antibiotics and many different creams and other treatments he was recently prescribed cleocin for this condition. is this a tried and proven way to get rid of this bacteria?