Transdermal absorption of lidocaine was determined by measuring plasma lidocaine
concentrations following skin application of 5% lidocaine patches. Two lidocaine patches
were placed on the ventral abdominal midline of seven dogs for 72 hours. Lidocaine was
detectable in plasma 12 hours after patch application, and it reached steady-state
concentrations between 24 and 48 hours. Plasma lidocaine levels decreased dramatically at
60 hours post-application. Low plasma lidocaine concentrations remained for 6 hours after …

The objective was to compare plasma lidocaine concentrations when a commercially
available 5% lidocaine patch was placed on intact skin vs. an incision. Our hypothesis was
that greater absorption of lidocaine would occur from the incision site compared to intact
skin. Ten dogs were used in a crossover design. A patch was placed over an incision, and
then after a washout period, a patch was placed over intact skin. Plasma lidocaine
concentrations were measured at patch placement; 20, 40 and 60 min; and 2, 4, 6, 12, 24 …