is glutamate effective/or not vs peripheral neuropathy from paclitaxel?

[Lani]

ABSTRACT: Long-term glutamate supplementation failed to protect against peripheral neurotoxicity of paclitaxel [European Journal of Cancer Care]
Toxic peripheral neuropathy is still a significant limiting factor for chemotherapy with paclitaxel (PAC), although glutamate and its closely related amino acid glutamine were claimed to ameliorate PAC neurotoxicity. This pilot trial aimed to evaluate the role of glutamate supplementation for preventing PAC-induced peripheral neuropathy in a randomized, placebo-controlled, double-blinded clinical and electro-diagnostic study. Forty-three ovarian cancer patients were available for analysis following six cycles of the same PAC-containing regimen: 23 had been supplemented by glutamate all along the treatment period, at a daily dose of three times 500 mg (group G), and 20 had received a placebo (group P). Patients were evaluated by neurological examinations, questionnaires and sensory-motor nerve conduction studies. There was no significant difference in the frequency of signs or symptoms between the two groups although neurotoxicity symptoms presented mostly with lower scores of severity in group G. However, this difference reached statistical significance only with regard to reported pain sensation (P = 0.011). Also the frequency of abnormal electro-diagnostic findings showed similarity between the two groups (G: 7/23 = 30.4%; P: 6/20 = 30%). This pilot study leads to the conclusion that glutamate supplementation at the chosen regimen fails to protect against peripheral neurotoxicity of PAC.

[Debbie L.]

I'm pretty sure that in 2001, the l-glutamine dose that was recommended was 5 grams ('can't recall if that was daily or twice daily). I remember taking many many capsules of 500mg l-glutamine - so many that a chemo buddy got impatient and gave me hers so she could buy the powder and drink it in juice. And we were taking a dose at the lower end of the ranges we'd seen in a few studies (there was very little evidence either way). The studies we saw were with prostate cancer.

Anecdotally, I had very little neuropathy and my chemo buddy who was taking the same dose of l-glutamine had rather severe neuropathy that did mostly resolve over about 6 months. Also of note, she was put on a prophylactic antibiotic with each chemo cycle, after running a fever with her first chemo cycle. The antibiotic was Cipro. As we were finishing chemo, there was the anthrax stuff going on, and after that there were stories of increased reports of neuropathy from Cipro (given for possible anthrax exposure). So who knows.

If I read this study correctly, they used only 1500mg (1.5Gms)/day.

Debbie Laxague