4CPS-164\u2005Oral ketamine in unmanageable chronic pain: a case report

Abstract

Background The neuropathic pain management which is refractory to opioids treatments demands the development of new analgesics or new ways of using our classic medicines. Ketamine is scarcely used as an anaesthetic, but with an increase in indication as an analgesic. However, no oral formulation is commercialised in our country. Purpose To develop an oral formulation of ketamine and assess its efficacy in refractory neuropathic pain. Material and methods A clinical record review of a 43-year-old male was carried out. After an accident in 2006, he experienced unapproachable neuropathic pain and he had a history of two admissions due to autolytic ideation motivated by poor pain control. From 2008 to 2015 he had been in treatment with various opiods and other non-opioid analgesics and antiinflamatory drugs, without pain control or improvement despite high doses. A ketamine oral solution was developed at the pharmacy according to Good Manufacturing Practice: 20\u2009ml of Ketolar 50\u2009mg/ml ampoule and syrup quantity sufficient for 100\u2009ml, obtaining 10\u2009mg/ml of oral solution. Results In September 2016, the patient started with intravenous ketamine at a dose of 0.2\u2009mg/kg with prior informed consent. He received three sessions with a 50% pain relief on the Global Clinical Impression Scale (GGI). On March 2017, the pain reappeared, and sessions were repeated monthly with a good response. In that time, the dose of transdermal fentanyl was reduced. In June 2017, oral ketamine solution 10\u2009mg/ml was formulated, dosed at 50–70\u2009mg/8\u2009hours. The patient scored 9 for his quality life on the GGI scale. As an adverse reaction, a slight and transient dizziness was observed. In August 2017, he continued with a descending pattern of opioids to discontinue. Currently, the patient continues with oral ketamine dosed at 50\u2009mg/8\u2009hours and fentanyl on demand, and the pain is well controlled. Conclusion The ketamine solution formulated has contributed to the control of the neuropathic pain and achieving the therapeutic objectives. Besides, it has reduced the opioids dose of this patient. References and/or acknowledgements 1. Neira Reina F. La ketamina en el tratamiento del dolor crónico según medicina basada en la evidencia. Rev Soc Esp Dolo 2016;23:292–306. No conflict of interest.