Fig. 1.

Taken according to the initial drug used. In patients who develop grade 2 to 4 allergic reactions, the preparation is switched without activity monitoring. In patients who present grade 1 reactions or questionable reactions, the monitoring of the activity that varies according to the initial drug used is indicated. (A) the starting drug is E. coli ASNase, monitoring should be done after the first dose and after each reintroduction, which usually takes 72 h. If it has activity <0.1 IU/ml, it is suggested to switch to another formulation, PEG-ASNase or Erwinia. But if it has activity ≥0.1 IU/ml they maintain the infusions of E. Coli ASNase. (B) the starting drug is PEG-ASNase, monitoring is indicated at day 7 after infusion. If the patient exhibits activity <0.1 IU/ml, swicth for Erwinia is suggested. If the activity is ≥0.1 IU/ml, it is monitored again on day 14, if the patient has activity <0.1 IU/ml, it is suggested to change to Erwinia and if it has activity ≥0.1 IU/ml maintain the infusions of PEG-ASNase.