Inclusion criteria:
Histologically confirmed stage II-IV colorectal cancers, scheduled to receive oxaliplatin-based chemotherapy (XELOX or FOLFOX with 85 or 130 mg/m2 oxaliplatin every 2 or 3 weeks, respectively
≥18 years of age
Eastern Oncology Group (ECOG) Performance Status 0, 1 or 2
The following laboratory values obtained ≤30 days prior to registration: • PLT ≥100,000 • WBC ≥3000 • HgB ≥10 • Total bilirubin ≤1.5 x upper normal limit (UNL) • Serum creatinine ≤1.5 x UNL • AST, ALT ≤ 2.5 x UNL
Negative pregnancy test (serum or urine) done ≤ 7 days prior to registration, for women of childbearing potential only
Willingness to take part in the study and ability to complete questionnaire by themselves or with assistance and to do study protocol
Provide informed written consent, with the right that patients could stop whenever they want
Exclusion criteria:
Pregnancy, lactation or unwilling to employ adequate contraception for women of childbearing potential
Prior treatment with neurotoxic chemotherapy such as oxaliplatin, cisplatin, taxanes, or vinca alkaloids
Pre-existing peripheral neuropathy (motor or sensory) of any grade
A family history of a genetic/familial neuropathy
Other medical conditions which, in the opinion of the treating physician, would makes the patient unable to participate in the study (because of safety concerns or noncompliance)
Inability to swollow
Allergy to oxaliplatin, leucovorin, fluorouracil, capecitabine, melatonin or excipients present in formulation of any of them
Concurrent consumption of other medications which are effective in preventing or treating neuropathic pain like carbamazepine, phenytoin, valproic acid, lamotrigin, gabapentin, pregabalin, venlafaxine, duloxetine, tricyclic antidepressants (such as amitryptilline), topical lidocaine, topical capsaicin, supplements like L-Carnitine or vitamin B1 and B6 or any other agent specifically being given to prevent or treat neuropathic pain
Diabetes mellitus