Lidocaine (IV Infusion — Opioid-Sparing Analgesia)

How it works

Systemically, lidocaine blocks sodium channels and modulates inflammatory and nociceptive signalling, producing analgesic, anti-hyperalgesic and anti-inflammatory effects that reduce opioid requirements.

Prescribing in practice

• Administer only under a strict local protocol with weight-based dosing, infusion pumps and continuous monitoring, because systemic accumulation causes local-anaesthetic toxicity (perioral numbness, tinnitus, seizures, arrhythmias and cardiac arrest); avoid concurrent use with other systemic or regional local anaesthetics that add to the total load.
• Use cautiously and reduce dose in hepatic impairment, cardiac conduction disease and the elderly, and stop promptly at any sign of toxicity.
• This is an unlicensed analgesic application of lidocaine; ensure lipid emulsion and resuscitation facilities are immediately available.

Monitoring

Monitor ECG, blood pressure, conscious level and for early neurological toxicity throughout the infusion, with defined limits on total dose and duration.

Counselling the patient

• Explain a controlled lidocaine drip may be used to reduce pain and the need for strong opioids after surgery.
• Tell staff straight away about numbness around the mouth, ringing in the ears, dizziness or a metallic taste.

Evidence & guidelines

Perioperative IV lidocaine for opioid-sparing analgesia is supported by trial and enhanced-recovery evidence in abdominal surgery, used off-licence under protocol owing to its narrow systemic safety margin.