Mokhtar, G.M., Shaaban, S.Y., Elbarbary, N.S., & Fayed, W.A. (2010). A trial to assess the efficacy of glutamic acid in prevention of vincristine-induced neurotoxicity in pediatric malignancies: A pilot study. Journal of Pediatric Hematology/Oncology, 32, 594–600.

The aim of the study was to evaluate the value of glutamic acid as a modifier in vincristine-induced neurotoxicity.

Children were randomized to treatment or placebo groups during adjuvant treatment with vincristine. Patients were evaluated weekly by physical examination. The treatment group received glutamic acid 1.5 g orally per day in three divided doses during a four-week induction with vincristine.

• The sample consisted of 94 pediatric patients (72% male and 28% female) with a mean age of 7.1 years (range of 3–18).
• The patients had acute lymphoblastic leukemia, non-Hodgkin lymphoma, or Wilms tumor.

The study was conducted at a single site in Egypt.

Phase of Care

• Active antitumor treatment

Clinical Applications

• Pediatrics
   

The study had a double-blind, randomized, placebo-controlled design.

• Achilles tendon reflex and patellar reflex were graded as normal, decreased, or absent.
• Parasthesis was recorded as absent, mild, moderate, and severe.
• Strength was assessed as normal, mild decrease, moderate decrease, and severe decrease.
   

Achilles and patellar reflexes were decreased at weeks 3 and 4 in more patients receiving placebo. Prevalence of mild parasthesias was greater in the placebo group at week 4. No severe parasthesias were recorded in the glutamic acid group compared to an incidence rate of 7.5% in the placebo group. The differences were not statistically significant.

The findings suggest that glutamic acid may be helpful in reducing vincristine-induced peripheral neuropathy symptoms in pediatric patients.

• Limitations include the small sample size (less than 100), measurement validity and reliability, and the findings not being generalizable.
• The method of grading reflexes and symptoms was not shown to be reliable, and physical examinations and grading were done by different physicians.
• Although the article states that patients were randomly assigned, it also states that the oncologist decided on the treatment, so assignment method is unclear.
• It is not stated whether there were any chemotherapy dose adjustment or delays.
• The article notes that “other treatments” were at the physician's discretion, so it is unclear if only glutamic acid was given for neuropathic effects.

 The findings suggest that glutamic acid may be helpful in managing peripheral neuropathy from vincristine; however, several study limitations exist. Additional well-designed research in this area is warranted.