Toxicity patterns associated with chronic ketamine exposure (2023)

Introduction: Synthesized in 1962, ketamine is used as a sedative, antidepressant and for the management of complex chronic pain. More recently, besides its therapeutic use, ketamine has been increasingly used as a recreational drug among young adults. As a result, an increasing number of reports have described side effects associated with its chronic exposure. This review aims to present the current evidence on the toxicity associated with chronic ketamine exposure.
Method: Considering the limited literature on the topic, Pubmed and Embase were searched and all types of articles were considered, including systematic reviews, retrospective studies, case series and animal studies.
Evidence: Chronic ketamine exposure is associated with urological toxicity manifesting mainly by lower urinary tract symptoms with features of ulcerative cystitis. More severe forms with upper urinary tract involvement can require multiple line treatments, including surgery. There are reports of gastrointestinal toxicity with abdominal pain, liver function test derangement and cholangiopathy. More recently, reports have described the association between prolonged ketamine sedation during covid-19 outbreak and cholangiopathies. Development of tolerance, brain and psychiatric changes have been described. These can manifest in cognitive impairment and psychiatric disorders, with schizophrenia-like symptoms. Possible cardiovascular alterations have been described in few reports. Whereas supportive treatment can offer transient relief, ketamine cessation remains the cornerstone of the treatment.
Conclusion: There is evidence of toxicity associated with chronic ketamine exposure on the different systems studied in this review. Nevertheless, due to the limitation of the studies more prospective studies would be required to clarify those findings.