Subcutaneous Injection of Botulinum Toxin A Is Beneficial in Postherpetic Neuralgia

• Published in: Pain medicine (Malden, Mass.) Vol. 11; no. 12; pp. 1827 - 1833
• Main Authors: Xiao, Lizu, Mackey, Sean, Hui, Hui, Xong, Donglin, Zhang, Qian, Zhang, Deren
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01-12-2010
• Subjects: Analgesics, Opioid - therapeutic use; Anesthetics, Local - administration & dosage; Anesthetics, Local - therapeutic use; Botulinum Toxin A (BTX-A); Botulinum Toxins, Type A - administration & dosage; Botulinum Toxins, Type A - therapeutic use; Double-Blind Method; Humans; Injections, Subcutaneous; Lidocaine - administration & dosage; Lidocaine - therapeutic use; Neuralgia, Postherpetic - drug therapy; Neuromuscular Agents - administration & dosage; Neuromuscular Agents - therapeutic use; Pain Measurement; Placebos - therapeutic use; Postherpetic Neuralgia (PHN); Prospective Studies; Quality of Life; Subcutaneous Injection; Treatment Outcome
• ISSN: 1526-2375; 1526-4637
• DOI: 10.1111/j.1526-4637.2010.01003.x

Objective.  To assess the benefits of subcutaneous injection of botulinum toxin A (BTX‐A) for the treatment of postherpetic neuralgia (PHN).
Design.  We investigated the therapeutic benefits of BTX‐A in subjects with PHN in a randomized, double‐blind, placebo‐controlled study. Sixty subjects with PHN were randomly and evenly distributed into BTX‐A, lidocaine, and placebo groups.
Measures.  After randomization, one of the following solutions was injected subcutaneously in the affected dermatome: 5 u/mL BTX‐A, 0.5% lidocaine, or 0.9% saline (placebo). Visual analog scale (VAS) pain and sleeping time (hours) were evaluated at the time of pretreatment, day 1, day 7, and 3 months posttreatment. Opioid usage was calculated at day 7 and 3 months posttreatment.
Results.  Compared with pretreatment, VAS pain scores decreased at day 7 and 3 months posttreatment in all three groups (P < 0.01). However, the VAS pain scores of the BTX‐A group decreased more significantly compared with lidocaine and placebo groups at day 7 and 3 months posttreatment (P < 0.01). Sleep time (hours) had improved at day 7 and at 3 months compared with pretreatment in all three groups, but the BTX‐A group improved more significantly compared with lidocaine and placebo groups (P < 0.01). The percent of subjects using opioids posttreatment in the BTX‐A group was the lowest (21.1%) compared with the lidocaine (52.6%) and placebo (66.7%) groups (P < 0.01).
Conclusions.  Subcutaneous administration of BTX‐A significantly decreased pain in PHN and reduced opioid use compared with lidocaine and placebo at day 7 and 3 months post‐treatment. It also increased subjects' sleep times.