Voraxaze skulle have været anvendt hos patienter, der kommer ud for sådanne giftvirkninger eller til at forebygge dem hos patienter, der har risiko for at få dem, f. eks. patienter med høj koncentration af methotrexat i blodet eller med dårlig nyrefunktion (som kan forsinke udskillelsen af methotrexat).
Voraxaze would have been used either as a treatment in patients who had developed such toxic effects, or as prevention in patients who were at risk of developing them, such as patients who have high levels of methotrexate in their blood, or those who have poorly functioning kidneys (when methotrexate may be eliminated more slowly).