Som med anden antihiv- medicin kan patienter, der tager Fuzeon, have risiko for at udvikle osteonekrose (knoglevævsdød) eller immunt reaktiveringssyndrom (symptomer på infektion forårsaget af genopretning af immunsystemet).
As with all other anti-HIV medicines, patients taking Fuzeon may be at risk of osteonecrosis (death of bone tissue) or immune reactivation syndrome (symptoms of infection caused by the recovering immune system).