[Differences in pain anesthetic effect expression on using lidocaine tape for hemodialysis patients]

There are many clinical problems which are raised but not responded sufficiently, and pharmacy school plays a key role to solve these problems. We introduce the case in which pharmacy school collaborated with hospital about the clinical problem. Many hemodialysis patients experience much physical and mental pain associated with needle insertion before dialysis. To alleviate this, tape-type lidocaine-containing local anesthetic patches (Penles, Wyeth, Japan) are widely used. However, the efficacy of Penles in alleviating pain associated with needle insertion is often limited. Hemodialysis patients exhibit a variety of dermatological symptoms, such as pruritus, xerosis, and erythema. These symptoms may affect the transdermal lidocaine absorption. We surveyed the current use of Penles and evaluated skin conditions in hemodialysis patients. The results revealed that hemodialysis patients had applied Penles for about 100 minutes, and the electrical capacitance of the skin surface of hemodialysis patients was significantly lower than that of healthy volunteers. In consideration of these results, we investigated a skin hydration method to enhance the absorption of lidocaine with porcine ear skin. In the result, lidocaine concentration increased significantly with skin hydration. Furthermore, this method was examined with hemodialysis patients, and the results revealed that this skin hydration method might be beneficial. This case was carried out by the collaboration between hospital and pharmacy school, and a clinical sense is necessary for such pharmaceutical research.