From the Research
The maximum recommended dose for lidocaine patches is 3 patches applied simultaneously for up to 12 hours within a 24-hour period, as supported by the most recent and highest quality study 1. Each patch typically contains 5% lidocaine (700 mg per patch), though only a small fraction of this amount (3%) is actually absorbed systemically. Patches should be applied to intact skin over the most painful area, with at least 12 hours without patches in each 24-hour period to minimize risk of toxicity. Some key points to consider when using lidocaine patches include:
- Patients should avoid applying patches to irritated or damaged skin, and should not cut patches as this can alter drug delivery and increase absorption.
- Lidocaine works by blocking sodium channels in nerve membranes, reducing pain signal transmission.
- Caution is needed in patients with severe hepatic impairment, as they may have reduced clearance of lidocaine, potentially leading to accumulation with repeated dosing.
- If patients experience signs of systemic toxicity (dizziness, confusion, numbness around the mouth, metallic taste, or cardiac arrhythmias), they should remove the patches immediately and seek medical attention. The study by 1 compared the efficacy and safety of lidocaine 700 mg medicated plaster vs. pregabalin, and found that lidocaine was similar to pregabalin in reducing pain, but had a better adverse events profile. Additionally, the study by 2 examined the pharmacokinetics and safety of continuously applied lidocaine patches 5%, and found that plasma lidocaine concentrations remained well below those that typically produce antiarrhythmic effects or toxicity. However, it is essential to prioritize the most recent and highest quality study, which is 1, when making a definitive recommendation.