Current use of drugs affecting the central nervous system for chemotherapy-induced peripheral neuropathy in cancer patients: a systematic review

Chemotherapy-induced peripheral neuropathy (CIPN) is common among cancer patients who undergo chemotherapy with platinum analogues, taxanes, vinca alkaloids, epothilone, bortezomib, and thalidomide. The purpose of this study was to investigate the evidence of using drugs affecting the central nervous system (CNS) to alleviate CIPN in cancer patients. A systematic literature search was conducted using the CINAHL, EMBASE, and Medline databases to identify randomized controlled clinical trials (RCTs) reported in English up to 2013. We identified ten trials of CNS-acting drugs used to treat CIPN in cancer patients and reviewed efficacy and safety of CNS-acting drugs for CIPN using a standard data collection form. The risk of bias in each RCT was also assessed. Antidepressants were used in six studies and anticonvulsants in four studies. We found positive results for amitriptyline (topical), venlafaxine, and oxcarbazepine in one study each, but the results were not sufficient to draw definite conclusions. One trial with duloxetine showed a moderate effect (effect size, 0.513, P = .003) on CIPN pain relief. However, none of the results has yet been duplicated in an RCT with a large sample size. Insufficient RCTs exist to confirm the efficacy of CNS agents to reduce CIPN. This study highlighted the need for and the importance of conducting well-designed RCTs to generate evidence on CIPN symptom management. Additional RCTs are warranted to accelerate the potential use of CNS drugs for CIPN in cancer patients.