Efficacy and safety of lidocaine infusion treatment for neuropathic pain: a randomized, double-blind, and placebo-controlled study

Neuropathic pain (NeP) represents one of the biggest challenges for pain specialists. The number of systemic reviews has been suggested lidocaine infusion therapy for NeP. However, it was unclear whether repeated LIT can result in prolonged pain relief. Therefore, this study showed that LIT provided effective short-term pain relief, which was substantially prominent after repeated infusions were administered to patients with refractory NeP.

Lidocaine infusion therapy (LIT) is considered a practical approach to managing neuropathic pain (NeP). Although, whether pain relief can be maintained throughout the repeated lidocaine infusions is unclear. This study aimed to evaluate whether repeated intravenous low-dose lidocaine could dispense extended pain relief among patients with critical NeP problems.

The patients with complex regional pain syndrome type II or postherpetic neuralgia compared for efficacy and safety of 3 mg/kg lidocaine infusions (LIT group) and normal saline infusions (control group) which administrated for a week for four consecutive weeks. The difference in the percentage change in the 11-point numerical rating scale (NRS) pain score from pre to postoperatively was considered as the primary outcome and pain scores during four weeks of follow-up along with any complications as the secondary outcomes. 

A total of 42 patients performed the analysis. The LIT group exhibited a more significant percentage decrease in NRS pain scores than the control group. Although, the pain detected after the 4-week follow-up. The LIT group also exhibited a prominent difference in the percentage change in NRS pain scores after the third and fourth infusions. No severe complication rate was noticed during the analysis. 

3 mg/kg of Lidocaine over one hour produced effective short-term pain relief, considerably prominent after repeated infusions.