Abstract
There have been few reports on valproic acid (VPA) -mediated pain control in multiple mono-neuropathies accompanied by vasculitis. We present a case of the successful treatment of Churg-Strauss Syndrome (CSS) -induced neuropathic pain with VPA. The patient was a 74 year-old man who was diagnosed with CSS based on the history of bronchial asthma, multiple peripheral neuropathy, eosinophilia, and vasculitis. The degree of neuropathic pain was assessed using the pain score. He had been given prednisolone, diazepam, carbamazepine, naproxen and amitriptyline before treatment with VPA but their analgesic effects were not sufficient. The administration of VPA was started at a dose of 400 mg/day and when the dose was increased to 800 mg/day, there was a marked decrease in Pmax and it stayed at a low level thereafter. The mean area under the daily pain score vs. time curve (AUC) during the treatment with VPA at 800 mg/day was significantly less than that for 600 mg/day. The steady-state plasma concentrations of total and free VPA at a dose of 800 mg/day were 62.1μg/mL and 8.8μg/mL, respectively. Our results indicate that when administered in the therapeutic range for patients with epilepsy, VPA is also effective in the treatment of neuropathic pain induced by CSS.
