Twenty-three RCTs were identified but only six reported the change in pain from baseline and were included in the limited network meta-analysis. Trials met between two and four of the six quality criteria.
Lidocaine medicated plasters versus pregabalin (one RCT, n=193 patients): The trial met four of the six quality criteria; trial duration was four weeks. Pregabalin dose was titrated from 150 to 300mg/day; up to four lidocaine medicated plasters were allowed in 24 hours. There was no significant difference between treatments in the primary trial outcome (numerical rating scale or NRS-3 response, defined as a reduction of at least two points or an absolute value of 4 or less on NRS-3 scale) or per protocol analyses of the following outcomes: change in NRS for pain intensity from baseline; patient and clinician assessed global pain relief; severity of allodynia; and patient satisfaction. There was a statistically significant improvement in quality of life (as measured by EuroQuol Dimension, EQ5D) associated with 5% lidocaine medicated plasters compared with pregabalin (difference 0.07, 95% CI 0.01 to 0.13). Pregabalin was associated with significantly higher rates of: any adverse event (RR 0.40, 95% CI 0.28 to 0.58); drug-associated adverse events (RR 0.14, 95% CI 0.07 to 0.27); discontinuation of treatment due to adverse events (RR 0.23, 95% CI 0.11 to 0.45); and discontinuation of treatment due to drug-related adverse events (RR 0.11, 95% CI 0.04 to 0.30).
Limited network meta-analysis (six RCTs, n=769 patients, range 22 to 254): Trial duration ranged from four to 12 weeks. The drugs examined in this analysis were 5% lidocaine medicated plasters, amitriptyline, pregabalin, capsaicin, gabapentin and placebo. The authors stated that all interventions were effective in comparisons to placebo. Lidocaine medicated plasters were comparable to all the other interventions.