Wang, W.S., Lin, J.K., Lin, T.C., Chen, W.S., Jiang, J.K., Wang, H.S., . .  Chen, P.M. (2007). Oral glutamine is effective for preventing oxaliplatin-induced neuropathy in colorectal cancer patients. Oncologist, 12, 312–319.

The purpose of the study was to evaluate whether oral glutamine reduced the incidence and severity of peripheral neuropathy in patients receiving oxaliplatin.

A total sample size of 86 patients with colorectal cancer were enrolled. Forty-two patients received glutamine and 44 did not. Patients received oxaliplatin 85 mgm/m², 5-FU  bolus 500 mgm/m², and folinic acid 20 mgm/m². Patients received glutamine 15 g twice a day for seven days every two weeks starting on the day of treatment. Patients were assessed at baseline for neurological toxicity and electrophysiological toxicity and again assessed at cycles 2, 4, and 6.

The 86 patients enrolled in the study had adenocarcinoma of the colon or rectum.

The study took place from September 2004 to December 2005.

The study had a non-randomized, pilot design.

Glutamine supplementation significantly reduced the incidence and severity of oxaliplatin-induced neuropathy. After two cycles of treatment, grade 1–2 sensory neuropathy was significantly lower in the intervention group versus the control group. The percentage of grade 3–4 sensory neuropathy was lower in the glutamine group after four cycles of treatment and remained that way for six cycles. In addition, glutamine supplements lowered peripheral nerve hyperexcitability and interference with activities of daily living. Glutamine supplementation also reduces the need for oxaliplatin dose reduction without affecting response to chemotherapy and survival.

• Concerns exist concerning glutamine supplements possibly protecting tumor cells from the cytotoxic effects of chemotherapy.
• The study was a non-placebo controlled, non-blinded study with a relatively small sample size; therefore, causality cannot be inferred.
• There was no between-group difference detected. 

Glutamine is a potential neuroprotective agent that needs to be studied in larger populations in a randomized, placebo-controlled trial.