Ultrasound‐Guided Liposomal vs. Conventional Bupivacaine Erector Spinae Plane Block Plus Gabapentin for Postherpetic Neuralgia

This study aimed to compare efficacy and safety of ultrasound‐guided erector spinae plane block (ESPB) using liposomal (LB) versus conventional bupivacaine (CB), each plus standardized gabapentin, in patients with postherpetic neuralgia (PHN). A total of 116 PHN patients were randomized to ESPB‐LB or ESPB‐CB; both groups received standardized gabapentin. The primary outcome was resting pain assessed by Numeric Rating Scale (NRS). Secondary outcomes were 72‐h event‐free time (time to first rescue medication or resting NRS ≥ 4), cumulative rescue opioid exposure in morphine milligram equivalents (MME), sleep by the Pittsburgh Sleep Quality Index (PSQI), health‐related quality of life by the Patient‐Reported Outcomes Measurement Information System (PROMIS), Patient Global Impression of Change (PGIC), and adverse events (AEs). ESPB‐LB achieved lower resting NRS at day 1, day 3 and day 7 (all p < 0.05), with no between‐group differences at day 30 or day 60. Event‐free time favored LB (median 54.10 h vs. 18.95 h; log‐rank p = 0.002). LB reduced cumulative MME at 48 h and 72 h, with convergence by days 7–60. PGIC favored LB at days 7 and 30, converging by day 60. Sleep and health‐related quality of life improved similarly with no between‐group differences; AEs were comparable, and no serious events occurred through day 60. In PHN, ESPB‐LB plus gabapentin provided an early advantage characterized by superior early analgesia, higher early responder rates, longer opioid‐free analgesia within 72 h, and short‐term opioid sparing versus ESPB‐CB, while longer‐term outcomes and safety profiles were similar between groups.