Lidocaine Medicated Plaster Effective Treats Postherpetic Neuralgia

A lidocaine medicated patch is both effective and well-tolerated for the treatment of postherpetic neuralgia, according to results of a real-world study published in Pain Management.

Researchers therefore sought to provide supporting real-world evidence for the use of lidocaine medicated plaster 700 mg to treat postherpetic neuralgia using data from the German Pain e-Registry.

Investigators conducted a noninterventional retrospective cohort study to compare tolerability and effectiveness of lidocaine medicated plaster with other oral systemic first-line treatments in patients refractory to at least 1 recommend oral first-line medication.

Data from patients who initiated treatment prior to December 2018 but before July 2019 were extracted. Patients with a 3-month pain history and medically confirmed peripheral neuropathic pain were assessed. Effectiveness of treatment was determined using patient-reported information on pain intensity, daily pain-related impairment, and quality of life, as well as overall quality of life and global impression of change.

A total of 3081 patients with peripheral neuropathic pain, of whom 1711 had postherpetic neuralgia, were included in the analysis after propensity score matching. Participants were primarily women over the age of 60 and almost all experienced comorbidities and took concomitant medications. More than 60% of patients had pain duration of more than 1 year. At baseline, pain intensity was high and accompanied by “considerable impairments” in daily activities and a marked impact on quality of life.

Patients in the lidocaine medicated plaster group received a mean of 1.8±0.9 patches per day (range, 1-4 patches), with a mean treatment duration of 145±46.3 days. Over 26% of patients experienced premature discontinuation of medication, primarily because pain treatment was no longer required (15.7%). Other reasons included adverse events (4.8%), lack of efficacy (3.9%), and unclear information (2.2%).

Patients in the oral medication group received tricyclic antidepressants, selective serotonin-norepinephrine reuptake inhibitors, or antiepileptic medications (32.3%, 32.3%, and 35.5%, respectively). These medications primarily included pregabalin, duloxetine, and amitriptyline. Mean treatment duration was 102.9±66.7 days, and a total of 53.8% of patients in this group discontinued therapy.

At baseline, all patients received concomitant analgesic medications. Most received up to 2 additional treatments for peripheral neuropathic pain. At 24 weeks, a significant reduction in concomitant medications was noted in the lidocaine group compared with the oral medication group (94.1% vs 70.9%).

Both treatment groups experienced a reduction in pain intensity during the observation period; however, this reduction was greater in the lidocaine group. Reductions in absolute change in the average pain intensity index from baseline was significantly higher in the lidocaine group at weeks 4, 12, and 24, with a strong effect size. Least squares mean absolute difference over all timepoints was -13.0±14.5 (95% CI, -13.8 to -12.3) mm VAS; the corresponding effect size was 1.1 (95% CI, 1.1-1.2). At 24 weeks, the relative mean change in pain intensity index was 52.5% and 29.4% for the lidocaine and oral medication groups, respectively.

At baseline, patients were experiencing significant limitations in activities of daily living. These improved with both treatments over the observation period, but they were significantly greater in the lidocaine group. There were also notable improvements in both pain-related and overall quality of life from baseline.

Those in the lidocaine group experienced significantly fewer drug related adverse events (8.9% vs 58.1% in the oral medication group). These patients primarily reported application site and other skin-specific reactions. In the oral medication group, 24.2% of patients had nervous system adverse events, 23.2% had psychiatric adverse events, and 17.1% had gastrointestinal adverse events. The most common adverse events were somnolence and dizziness, nausea, and hyperhidrosis (15.8% and 5.1% of all patients).

Study limitations include those inherent to observational, retrospective, database research and a lack of generalizability outside of the narrowly defined study population.

“The analysis of real-world data…confirmed the effectiveness and good tolerability of the lidocaine 700 mg medicated plaster under routine medical care,” the researchers concluded. 

Disclosure: This clinical trial was supported by Grünenthal GmbH, Germany. Please see the original reference for a full list of authors’ disclosures.

Reference

Überall MA, Eerdekens M, Hollanders E, Bösl I, Sabatschus I. Lidocaine 700 mg medicated plaster for postherpetic neuralgia: Real-world data from the Germain Pain e-Registry. Pain Manag. Published online August 10, 2021. doi: 10.2217/pmt-2021-0022