[Ketamine and chronic pain: A narrative review of its efficacy and its adverse events].

Ketamine is frequently used in the management of refractory chronic pain. To date, the level of proof in the literature on ketamine in this type of indication is generally poor and physicians have no consensus or recommendation to support their practice. This narrative review is an update on literature data assessing the efficacy and safety of ketamine in chronic pain. The electronic search of the Medline, PubMed, Google Scholar and Cochrane databases identified a total of 61 articles including randomized and non-randomized trials and 14 international reviews. In view of these data, it is difficult to conclude on the effectiveness of ketamine in this type of indication and on its safety due to the heterogeneity of practice in terms of doses, routes, duration and frequency of administration and especially a lack of clinical trials with a high level of evidence.