(151) Treatment emergent mania during prolonged continuous ketamine infusion for chronic pain: a case report

Abstract:

Background:

Ketamine is a noncompetitive antagonist of the NMDA receptor that shows promising results in improving outcomes in complex pain syndromes^1,6. As pain medicine explores new ways of using ketamine, administration varies, which carries accompanying risks. There have been several case studies demonstrating that ketamine-induced mania poses risks for certain patient populations. 

Methods/

Results:
We describe a case of a 39-year-old woman with a history of functional pain, kidney autoimmune condition leading to a remote kidney transplant, and depression who developed prolonged mania in the setting of low-dose ketamine infusion for chronic abdominal pain. During her hospitalization, she received 2.5 mcg/kg/min for 13 continuous days, which, to our knowledge, is the longest documented ketamine infusion associated with mania as an outcome. Her symptoms included rapid speech, euphoria, poor sleep, distractibility, and delusions. After her medical hospitalization, she required one week of psychiatric hospitalization along with medication management. She responded to a second-generation antipsychotic and valproic acid, and she was subsequently discharged to the community on these medications. Confounding factors we explored include her home antidepressant and her immunosuppressants (tacrolimus and corticosteroid). These medications have been shown to potentially exacerbate mood symptoms, however, she had been on low-dose prednisone and tacrolimus for at least ten years prior, the latter of which had remained in the therapeutic range for many years. She had been on escitalopram three months prior, and duloxetine for several years prior. While all of these factors may have contributed to lowering the threshold, the timeline for ketamine infusion and the emergence of manic symptoms would more likely explain the clinical picture of her symptoms.

 

Discussion:
Literature review reveals that ketamine use and misuse can lead to psychosis or mania, and psychosis or mania should be considered a potential risk as psychiatrists and pain specialists begin to develop protocols for treating conditions³. Other case presentations have described ketamine-induced mania or psychosis where drip ketamine was used, but the indication and duration differed^2,4,5.

 

Conclusion/Implications
Understanding these risks in the field of consultation-liaison psychiatry is paramount, as there will likely be an increase in the use of ketamine drips for pain. While the consensus amongst anesthesia and pain management is that it’s especially efficacious, we should remain aware of the psychiatric side effects as they relate to patient outcomes and the risk factors that could predispose patients to ketamine-induced mania.

References

1. Brown, K. (2020). Ketamine for Acute Pain Management and Sedation. Critical Care Nurse, 40(5), e26–e32. https://doi.org/10.4037/ccn2020419


2. Hu, Y., … Frye, M. A. (2021). Hypomania associated with high dose ketamine treatment. Bipolar Disorders, 23(4), 426–428. https://doi.org/10.1111/bdi.13059


3. Lane, H.-Y. (2016). Mania following ketamine abuse. Neuropsychiatric Disease and Treatment, 237. https://doi.org/10.2147/NDT.S97696


4. Mandyam, M. C. (2017). Ketamine-Induced Mania During Treatment for Complex Regional Pain Syndrome. Pain Medicine, 18(10), 2040–2041. https://doi.org/10.1093/pm/pnx061


5. Nichols, S. D. (2016). A Case of Possible Iatrogenic Ketamine-Induced Mania in a Patient Being Treated for Postoperative Pain. Psychosomatics, 57(5), 543–546. https://doi.org/10.1016/j.psym.2016.06.003


6. Yang, Y. (2020). Emerging concepts on the use of ketamine for chronic pain. Expert Review of Clinical Pharmacology, 13(2), 135–146. https://doi.org/10.1080/17512433.2020.1717947

Presentation Eligibility: Not previously published or presented

Diversity, Equity, and Inclusion: This submission could advance equity in inclusion as we learn how to address pain management using different modalities, while also addressing the risks that come with them. Clinicians need to be acutely aware of the medications we prescribe our patients, especially those from historically marginalized groups so that adverse health outcomes can be avoided. Several patients who struggle with low socioeconomic status also struggle with barriers that would be worsened by prolonged mania. As the evidence builds, the risks/benefits of continuous ketamine infusion need to be carefully balanced so as not to worsen someone’s life situation.