Oral glutamine supplementation may enhance the therapeutic index by protecting normal tissues from, and sensitizing tumor cells to chemotherapy and radiation-related injury. There is evidence to suggest glutamine supplementation may decrease the incidence and/or severity of chemotherapy-associated mucositis, paclitaxel-induced neuropathy, and the cardiotoxicity that accompanies anthracycline use ( Savarese, 2003).
A phase III randomized, double-blind study at Mayo failed to note any significant reduction in acute diarrhea in patients undergoing pelvic radiation therapy taking 4 grams glutamine BID as compared to controls ( Kozelsky, 2003). However, it is possible that under severe stress, such as that encountered with pelvic RT, much higher levels of glutamine may be needed to maintain epithelial integrity in the gut ( Savarese, 1998)—doses of 20-40 grams per day have been suggested ( Hall, 1996). The study by Kozelsky et al, initiated glutamine at the onset of treatment, though, positive results have been primarily seen when started 5 days prior ( Daniele, 2001). Thus, many questions remain regarding dose, timing and effectiveness for oral glutamine in the prevention of radiation-induced GI toxicity.
Glutamine is a mainstay of integrative treatment for GI conditions including IBS, Colitis and leaky gut syndromes.