Table 4.
Representative studies of BTX in postherpetic neuralgia (PHN).
| First Author [Ref.], Year | Type of Study | n | Treatment Regimen | Outcome Measures | Follow-Up | Results (Including Adverse Effects) |
|---|---|---|---|---|---|---|
| Ding [31], 2017 | Prospective, single arm (BTX) | 58 | A single session of treatment was performed. BTX concentration: 4 IU/mL; Injection dose: 50–100 IU in total | Pain severity (VAS) Neuropathy pain scale (NPS) Quality of Life Scale (SF-36) PHN seizure severity, seizure duration, and frequency of attacks. The use of painkillers |
6 months | At 6 months follow-up, a significant decrease in seizure frequency, seizure duration, VAS score, NPS score, SF-36 score and the required amount of painkiller was observed (p < 0.05). After BTX injection, 4 patients complained of pain around the injection area which disappeared within a week. |
| Apalla [32], 2013 | Double-blinded RCT (BTX vs. saline) | BTX group: 15 Control group: 15 | BTX group: A single treatment delivered. BTX concentration: 25 IU/mL; Injection dose: each patient received 40 injections in total (5 IU/point). Control group: A single treatment with saline. |
Pain severity (VA) Quality of sleep |
4 months | Thirteen patients from the experimental arm achieved at least 50% reduction in VAS score, compared with none of the placebo group (p < 0.001). BTX patients showed significant reduction in VAS pain scores between baseline and week 2, which persisted for a median period of 16 weeks. BTX patients showed significant reduction in sleep scores between baseline and week 2, which remained unchanged until week 16 (p < 0.001). Treatment was well-tolerated. |
| Xiao [33], 2010 | Double-blinded RCT (BTX vs. 0.5% lidocaine vs. saline) | BTX group: 20 (19 completed) Lidocaine group: 20 (19 completed) Control group: 20 (18 completed) |
BTX group: A single injection. BTX concentration: 5 IU/mL; Injection dose: 200 IU at maximum. Lidocaine group: A single session of treatment of the same volume as BTX. Control group: A single injection of the same volume as BTX |
Visual Analogue Scale (VAS) Quality of Life Percent of Opioid use |
3 months | Compared with pretreatment, VAS pain scores decreased at day 7 and 3 months posttreatment in all 3 groups. However, the VAS pain scores of the BTX group decreased more significantly compared with lidocaine and placebo groups at day 7 and 3 months posttreatment (p < 0.01). Sleep time improved in all 3 groups but was most significant in the BTX group compared with the lidocaine and placebo groups (p < 0.01). The percentage of subjects using opioids posttreatment in the BTX was the lowest (21.1%), compared with the lidocaine (52.6%) and placebo (66.7%) groups (p < 0.01). |
BTX: Onabotulinum toxin unless otherwise stated, PHN: post-herpetic neuralgia.