Patients completed the Brief Pain Inventory Short Form and global pain assessments at baseline, Days 7 and 14, and study conclusion. My doctor has told me to discontinue use. Results from a large open-label controlled study suggest that the lidocaine plaster could be at least as effective as systemic pregabalin in the treatment of postherpetic neuralgia and painful diabetic polyneuropathy. Use of 5% lidocaine medicated plaster could reduce abnormal nervous peripheral discharge and via the plaster could have a “protective” function in the affected area. Overall, 66% of patients reported improvement in pain intensity, and 74% reported improved QOL by Day 7; approximately 43% who did not respond by Day 7 experienced improvement in pain intensity by Day 14. To evaluate this possible outcome, we retrospectively reviewed eight patients with PHN, treated using 5% lidocaine medicated plaster. The risk of systemic adverse events and pharmacokinetic interactions with concomitant medication is minimal owing to low systemic exposure.
Our study cohort was composed mainly of elderly patients taking multiple drugs to treat comorbidities, who have a high risk of drug-drug interactions. Based on results of previous randomized, controlled trials and the current study, designed to gauge response in the clinical practice setting, the lidocaine patch 5% should be considered a first-line therapy, alone or in combination with other agents, for PHN due to its efficacy, safety, minimal systemic side effects and drug interactions, and ease of administration. Our observations confirm the effectiveness of lidocaine plasters in the treatment of PHN, indicating that 5% lidocaine medicated plaster could reduce the size of the painful area. This last observation has to be confirmed and the mechanisms clarified in appropriate larger randomized controlled trials.