Bradfield, S.M., Sandler, E., Geller, T., Tamura, R.N., & Krischer, J.P. (2015). Glutamic acid not beneficial for the prevention of vincristine neurotoxicity in children with cancer. Pediatric Blood and Cancer, 62, 1004–1010. 

DOI Link

Study Purpose

To determine if glutamic acid is an effective preventative therapy in children with vincristine-associated neurotoxicity

Intervention Characteristics/Basic Study Process

Before the first treatment of vincristine, patients were stratified into stratum 1 or stratum 2. Stratum 1 included patients with Wilms tumor or rhabdomyosarcoma who were to receive nine weeks of vincristine; stratum 2 included patients with acute lympoblastic leukemia or non-Hodgkin lymphoma who were to receive four weeks of vincristine. Both groups were randomized to receive L-glutamic acid hydrochloride or placebo three times a day until seven days after week 4 or week 9 of vincristine. The placebo was administered in the same manner.

Sample Characteristics

  • N = Stratum 1: 16 placebo, 14 glutamic acid. Stratum 2: 84 placebo, 70 glutamic acid
  • AGE = 3–21 years
  • MALES: 52% (stratum 1), 62% (stratum 2)  
  • FEMALES: 46% (stratum 1), 38% (stratum 2)  
  • KEY DISEASE CHARACTERISTICS: Patients with Wilms tumor, rhabdomyosarcoma, acute lymphoblastic leukemia, or non-Hodgkin lymphoma
  • OTHER KEY SAMPLE CHARACTERISTICS: All were newly diagnosed.

Setting

  • SITE: Single site
  • SETTING TYPE: Not stated
  • LOCATION: USA

Phase of Care and Clinical Applications

  • PHASE OF CARE: Active treatment
  • APPLICATIONS: Pediatrics

Study Design

A randomized, placebo-controlled, double-blind trial

Measurement Instruments/Methods

  • Modified Balis Pediatric Scale of Peripheral Neuropathies

Results

Patients who received glutamic acid did not have significantly less neurotoxicity symptoms compared to the placebo group. The subgroup of patients aged 13 years or older experienced more benefits from glutamic acid (0.28, p = 0.055) compared to patients younger than 13 years. Neurotoxicity rated less than 0.02 (p = 1) but was not statistically significant.

Conclusions

Glutamic acid is not considered an effective preventative treatment of neurotoxicities in preadolescents.

Limitations

  • Possible insufficient dosing of glutamic acid
  • Variability in neurological exams as well as data collection
  • Data were collected only for initial 5–10 weeks of therapy.
  • The researchers identified a small sample size.

Nursing Implications

Glutamic acid is not recommended for the prevention of neurotoxicities in pediatric patients at this time.