Paroxetine, as an Adjuvant Analgesic for the Management of Neuropathic Pain Syndrome

Han, Tae Hyung; Shin, Baek Hyo; Eun, Jong Shin; Lee, Sang Min

Abstract

BACKGROUND: Tricyclic antidepressants (TCA) have been used for various pain syndromes for their analgesic effects. They, however, often have anticholinergic side effects and therefore search for more selective drugs with fewer side effects is justified. Paroxetine, a selective serotonin reuptake inhibitor devoid of autonornic side effects, was evaluated for its role as an analgesic adjuvant in the management of neuropathic pain. METHOD: According to individual diagnostic group as diabetic neuropathy, postherpetic neuralgia, central pain syndrome and cancer related plexopathy, 10 patients per each group were equally accumulated. Patients have been stabilized in their analgesic regimen at least four weeks prior to enrollment into study. TCA, if taken, was discontinued for two weeks for wash out period. Baseline four point verbal pain intensity score was obtained and oral administration of paroxetine 20 mg was initiated. At two weeks follow-up visit, pain intensity scores, pain improvement scores judged by family, drug efficacy, tolerability and overall evaluation were assessed. The incidence of side effects were also obtained. RESULT: After two weeks of treatment, pain intensity scores decreased in 77.5% of patients and no patients experienced aggravation. These findings were objectively reflected in pain improvement scores judged by family members. But, the number of nonresponders was different among groups. In drug efficacy, tolerability and overall evaluation, the proportions of patients who scored as excellent or good were 75%, 80% and 80% respectively. Incidence of side effects was 27.5%, but the side effects spontaneously disappeared after discontinuation of medication.
CONCLUSION
Paroxetine, a selective serotonin reuptake inhibitor, appears to be effective as adjuvant analgesic for the management of various neuropathic pain syndromes.