Low-dose ketamine as an adjuvant for pain control in a cancer patient: a case report

Abstract

Cancer patients often suffer from pain related problems such as under-treatment of pain, ineffective and persistent opioid administration as well as adverse opioid use outcomes. There is a growing need for non-opioid analgesic alternatives for patients undergoing treatment for obstinate pain. Ketamine is a fast-acting N-methyl-D-aspartate (NMDA) receptor antagonist that has been emerging as an effective medication for pain alleviation. While protocols have been established for the use of Low-Dose Ketamine (LDK) for post-operative pain, there is growing evidence for using LDK as a clinical alternative to opioids in a palliative care setting. This case study involves monitoring the efficacy of LDK treatment in combination with opioid analgesics in a cancer patient in a hospital setting. This is a very selected case of a patient with Metastatic Prostate Cancer (Gleason 9 Adenocarcinoma) where LDK was shown to be efficacious at reducing pain when opioids and standard pain medications were not satisfactory. While the study involved using a relatively novel pharmacological protocol and close patient monitoring, the patient reported a sustained reduction in pain level based on the Numerical Rating Scale for months after the termination of LDK infusions. Moreover, the treatment also resulted in a reduction of total opioid usage after the addition of LDK. Although additional research is needed to ascertain optimal dosing schedules and route of Ketamine, given these promising findings, Ketamine may be a useful option for improving the treatment of refractory pain in patients with cancer and a good tool in palliative medicine for treating neoplastic pain.