[Preliminary study on the safety and pharmacodynamic action of low dose L-asparaginase].

OBJECTIVE

To investigate the safety and therapeutic effect of low dose (1000 U/m(2)) L-asparaginase (L-Asp) in the treatment of children with acute lymphoblastic leukemia (ALL).

METHODS

Six patients were treated with low dose L-Asp after previously suffered severe side effects from standard dose L-Asp (5000 - 10,000 U/m(2)). Twenty-eight blood samples were obtained randomly from 5 of them. Plasma asparagine concentration was detected by reverse phase-high performance liquid chromatography (RP-HPLC).

RESULTS

All the patients treated with low dose L-Asp showed no any toxic symptoms. The plasma asparagine levels in the patients were all above 5 micromol/L except case 4 (4.91 micromol/L) before receiving L-Asp, and were all decreased below 0.5 micromol/L five days after receiving low dose L-Asp, except case 3 (3.70 micromol/L), the results being like that of receiving standard dose L-Asp.

CONCLUSION

Low dose L-Asp has definite efficacy for childhood ALL, while avoids serious side effects from standard dose L-Asp.