A Randomized, Crossover, Pharmacokinetic and Adhesion Performance Study of a Lidocaine Topical System 1.8% During Physical Activity and Heat Treatment in Healthy Subjects.

Transient heat exposure resulted in increased lidocaine plasma concentrations compared to normal conditions, whereas exercise had no effect. The effects of heat appear to be immediate, reversible, and below systemic therapeutic threshold in antiarrhythmic treatment (1000-1500 ng/mL), and well below the safe systemic threshold of 5000 ng/mL. Lidocaine topical system 1.8% remained adhered to the skin and was well tolerated under all conditions. ClinicalTrials.gov: NCT04150536.