Preemptive Administration of Systemic Lidocaine Does Not Prevent Hyperalgesia in the Rat Chronic Constriction Injury Model of Neuropathic Pain
Purpose: Based on these results, we hypothesized that lidocaine, when administered at a low dose continuously during the initial phase of the development of thermal hyperalgesia, might permanently prevent the development of full hyperalgesia even after lidocaine administration was terminated.
Methods: Saline or lidocaine was administered via subcutaneously implanted pumps for 24 h prior to loose sciatic ligation in male Sprague-Dawley rats (300 g). Three days after ligation the pumps were removed. Thermal hyperalgesia was assessed at baseline (presurgery), and 3, 5, and 7 days after sciatic ligation.
Results: Lidocaine prevented the development of hyperalgesia during continuous systemic administration through the first 3 days after surgery. Following removal of the lidocaine pumps the magnitude of hyperalgesia was diminished, despite nondetectable plasma lidocaine concentrations, on day 5. However, by day 7 thermal hyperalgesia was pronounced and not different from that in rats that had received saline.
Conclusions: Lidocaine provides antihyperalgesia in a neuropathic pain model during continuous systemic administration. Administration of lidocaine only during the development of the neuropathic state temporarily diminishes the magnitude of hyperalgesia even when lidocaine is no longer present.
Document Type: Research Article
Affiliations: 1: *Department of Surgical Sciences, University of Wisconsin, 2015 Linden Drive, Madison, WI 53706 2: †Department of Comparative Biosciences, University of Wisconsin, 2015 Linden Drive, Madison, WI 53706
Publication date: December 1, 2001
- From 2003 onwards, published as Reviews in Analgesia