Can gradual dose titration of ketamine for management of neuropathic pain prevent psychotomimetic effects in patients with advanced cancer?

Am J Hosp Palliat Care. 2013 Aug;30(5):450-4. doi: 10.1177/1049909112454325. Epub 2012 Jul 24.

Abstract

Background: Ketamine is often used to manage neuropathic pain in patients with cancer. However, it occasionally causes psychotomimetic effects such as vivid dreams, nightmares, illusions, hallucinations, and altered body image.

Objective: To examine whether gradual dose titration of ketamine for management of neuropathic pain prevents psychotomimetic effects in patients with advanced cancer.

Methods: This was a retrospective chart review. We administered ketamine when neuropathic pain in patients with advanced cancer became refractory to opioids and oral adjuvant analgesics. The starting dose of ketamine was 10 mg/d by continuous intravenous infusion. The dose was gradually increased by 10 mg/d every 4 to 6 hours to 50 mg/d or until the pain was relieved. It was subsequently increased by 25 mg/d every 12 to 24 hours until the pain was relieved.

Results: For this study, we enrolled 46 patients with advanced cancer. The mean age was 52.2 ± 16.9 years. The mean dose at onset of action and maximum dose of ketamine were 56 ± 58 and 272 ± 214 mg/d, respectively. The mean pain intensity (numerical rating scale) decreased significantly from 7.3 ± 2.0 to 3.5 ± 2.2 after the administration of ketamine (P < .01). The effectiveness was 69.5%. No psychotomimetic effect of less than 300 mg/d was observed during the introduction phase even though psychotropic drugs were not prescribed. Mild sedation was observed in 3 patients (7%) as the only adverse effect during the introduction phase.

Conclusion: Gradual dose titration of ketamine for management of neuropathic pain can prevent psychotomimetic effects in patients with advanced cancer.

Keywords: cancer pain; ketamine; neuropathic pain; opioid; psychotomimetic effects; titration.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Analgesics / administration & dosage*
  • Analgesics / adverse effects
  • Analgesics / therapeutic use
  • Child
  • Female
  • Humans
  • Infusions, Intravenous
  • Ketamine / administration & dosage*
  • Ketamine / adverse effects
  • Ketamine / therapeutic use
  • Male
  • Middle Aged
  • Neoplasms / complications*
  • Neuralgia / drug therapy*
  • Pain Management / methods*
  • Pain Measurement
  • Psychoses, Substance-Induced / etiology
  • Psychoses, Substance-Induced / prevention & control*
  • Retrospective Studies
  • Young Adult

Substances

  • Analgesics
  • Ketamine