[The efficacy of intravenous lidocaine for acute herpetic pain--placebo controlled trial].

BACKGROUND: Acute herpetic pain (AHP) which is considered not only nociceptive pain but also neuropathic pain, is often severe and intractable. Although there have been reports of the efficacy of intravenous lidocaine (IVL) for neuropathic pain, the efficacy of lidocaine for AHP is not known. Therefore, the effect of IVL for AHP was examined. METHODS: The study included 43 patients, who visited our pain management office within 90 days after skin eruption of herpes zoster. This study was a randomized, placebo-controlled design. In group A, a continuous infusion of saline 100 ml for 30 min was given followed by a continuous infusion of IVL 3 mg x kg(-1) for 30 min. In group B, IVL 3 mg x kg(-1) for 30 min was given followed by saline 100 ml for 30 min. A pain relief score (PRS) was assessed at the end of each infusion. RESULTS: In group A, PRS decreased significantly with saline and decreased furthermore with IVL. In group B, PRS decreased significantly with IVL and did not change with saline. A reduction of PRS with IVL in group B was significantly greater than that with saline in group A. CONCLUSIONS: This study demonstrates that IVL has a significant analgesic effect in patients with AHP.