Lidocaine for Neuropathic Cancer Pain (LiCPain): a pilot randomised controlled trial

Extended continuous subcutaneous infusion of lidocaine for neuropathic cancer pain is currently used in clinical practice. To determine the feasibility of conducting an adequately powered, multisite, double-blind, parallel group, titrated dose, randomized controlled trial of continuous subcutaneous infusion of lidocaine versus placebo in palliative care patients with neuropathic cancer pain. Adults with neuropathic cancer pain were randomized to receive lidocaine hydrochloride 10%w/v (3000 mg/30 mL) diluted in sodium chloride 0.9% or sodium chloride 0.9% as a continuous subcutaneous infusion titrated daily for 72 hours. The dose increased from 1 to 2 mg/kg/h, capped at 120mg/hour (2800mg/day, rounded down). Seventeen participants were recruited over 54 months. There was a 93% [95%CI 88%-98%] completion rate of study medication and procedures meeting the predefined feasibility criteria. Eighty-eight percent of participants completed 72 hours of study medication. Treatment-emergent adverse events were infrequent and generally mild or moderate nervous system, cardiac and vascular abnormalities. There were no electrocardiogram abnormalities. Rapid titration from 1 to 2 mg/kg/h was tolerated. Both intervention and control groups demonstrated a reduction in pain intensity with no significant difference. This pilot demonstrates that a phase III clinical trial of extended continuous subcutaneous infusion of lidocaine for neuropathic cancer pain is feasible and provides important insights into modifications required to improve recruitment. Serum levels and relative safety suggest higher lidocaine doses could be cautiously evaluated. As the only prospective trial we are aware of to date, this trial informs clinical use of subcutaneous lidocaine infused over days.