Under fuld bedøvelse lægges der en stram bandage om øverste del af lemmet, så dets blodforsyning afbrydes og medicinen forhindres i at sprede sig til resten af kroppen.
Before Beromun is given, the limb is first isolated: while the patient is under general anaesthetic, a tight band is placed around the top of the limb to isolate its blood supply and prevent the medicine reaching the rest of the body.