Plasma Lidocaine Concentrations During Intravenous Lidocaine Infusion Therapy in the Pediatric Population—A Scoping Review

BACKGROUND: Intravenous lidocaine therapy (IVLT) is often used in perioperative multimodal analgesia due to its analgesic, anti-hyperalgesic, and anti-inflammatory effects. In adults, IVLT doses of 1-2 mg/kg/h produce plasma concentrations of 1-2 μg/mL, within the presumed therapeutic range of 1-5 μg/mL. The dose range, expected plasma concentrations, and presumed therapeutic range are not well defined in children. We aimed to review available pharmacokinetic data in pediatric patients receiving IVLT. METHODS: We searched MEDLINE, EMBASE, and CINAHL databases for studies reporting pharmacokinetic data for IVLT in healthy 1-18-year-olds, with plasma lidocaine or metabolite levels collected post-infusion, excluding studies involving non-therapeutic infusions or children with comorbidities affecting lidocaine metabolism. Bias was assessed using validated tools. We conducted narrative data synthesis due to reporting variability and summarized plasma lidocaine and/or metabolite levels and the incidence of reported adverse events. RESULTS: Four studies comprising 174 children were included. A study (n = 22) using a 1.5 mg/kg bolus over 30 min followed by a 1 mg/kg/h infusion for 6 h post-surgery achieved highest mean drug concentrations of 2.82 ± 0.65 μg/mL immediately following surgery. Another study (n = 46) utilized a 1.5 mg/kg bolus over 5 min followed by a 2 mg/kg/h infusion and achieved peak concentrations of 4 to < 5 μg/mL. Two studies (n = 106) utilized a 1.5 mg/kg bolus and 1.5 mg/kg/h infusion until transfer to the post-operative anesthesia care unit or six hours post-operatively achieved concentrations that were detectable and < 5 μg/mL. The only adverse event reported was a single participant who experienced transient sensory disturbances. CONCLUSION: Existing pharmacokinetic data for pediatric IVLT is extremely limited. Reported plasma concentrations were detectable and lower than presumed toxic levels with one reported adverse event. Large-scale, multicenter research is needed to determine optimal pediatric dosing, elucidate dose response curves, and ensure safe and effective use of IVLT in the pediatric population. TRIAL REGISTRATION: Prospective Register of Systematic Reviews (PROSPERO): CRD42025636554.