Retrospective Analysis of Neuropathic Pain Control in Patients with Advanced Cancer

Abstract

Objective To describe the use of sodium valproate in patients with advanced cancer for the relief of neuropathic pain. Design Case series. A retrospective, descriptive review using medical records. Setting Ambulatory and hospitalized patients referred to the Central Sydney Palliative Care Service, based at the Royal Prince Alfred Hospital, an 800-bed teaching hospital, in Sydney, Australia. Patients Of all the 364 patients who were referred to the Service in 1987, 64 received sodium valproate for neuropathic pain and were eligible for inclusion in the study. Main Outcome Measures Documentation by physicians of pain control and the dose of sodium valproate. Results Forty-three of the 64 patients (67 percent) had an indication of efficacy noted on their record. In 26 of these 43 patients (60 percent), sodium valproate was the only therapy introduced or the dosage was increased immediately prior to the documentation of pain relief. Only 3 patients totally discontinued sodium valproate. The 1 patient who experienced an adverse effect of sedation temporally related to institution of sodium valproate had therapy successfully reintroduced at a lower dosage. The dosages used for analgesia were much lower than those used for epilepsy. The mode and median doses were 400 mg/d (interquartile range 200–600 mg). Conclusions This medical record review raises the hypothesis that sodium valproate may be useful therapy in the management of cancer-related neuropathic pain.