Background and Objectives We report on the use of intravenous (IV) high-dose lidocaine to relieve diabetic neuropathic pain, and the technique's effects on clinical measures of lipid peroxidation.

Methods Under continuous electrocardiogram monitoring, IV lidocaine (5 mg kg⁻¹ in 100 mL saline) was administered over 30 minutes to 7 non-insulin-dependent diabetic patients suffering from neuropathic pain who reported increased pain within the preceding 6 months. This treatment was performed once a week for 1 month. Blood samples were collected from the contralateral limb to determine plasma superoxide dismutase (SOD) and malondialdehyde (MDA) levels on admission and following the final lidocaine administration.

Results Plasma MDA concentrations significantly decreased after the final IV lidocaine treatment (P < .05, paired t-test), whereas SOD levels did not show a statistically significant difference compared with baseline levels.

Conclusions High-dose lidocaine treatment lessens MDA levels, a marker of free-radical-mediated cell damage. This suggests that one of lidocaine's mechanism of action may be its effect on oxygen free radicals, which in turn impacts lipid peroxidation.