Oral Chinese herbal medicine for post-herpetic neuralgia: A systematic review and meta-analysis of randomized controlled trials

IntroductionPost-herpetic neuralgia (PHN) is a common complication of herpes zoster. Pain medications have shown benefit, however many patients do not achieve adequate pain relief. Oral Chinese herbal medicine (CHM) has been used for people with PHN but its benefit is unclear. This review examined the efficacy and safety of oral CHM alone or as add-on therapy for PHN.MethodsNine English and Chinese databases were searched from their inceptions to March 2016. Randomized controlled trials (RCTs) evaluating oral CHM for PHN were included. Methodological quality was assessed using the Cochrane Collaboration's risk of bias tool. Data were analysed using Review Manager software.ResultsTwelve RCTs involving 853 participants were included with low to moderate quality based on risk of bias assessment. Oral CHM as an add-on intervention to pharmacotherapy improved visual analogue scale (VAS) pain score (MD −1.88 cm [−3.34 to −0.42], I2 = 98%), and scores on the Hamilton Rating Scale for Depression (HAM-D) (MD −2.45 points [−3.70 to −1.20], I2 = 13%) compared with pharmacotherapy alone. Significant changes from baseline were seen for all groups. No severe adverse events were reported.ConclusionsThese findings suggested that oral CHM in addition to pharmacotherapy may be beneficial for patients with PHN. Oral CHM alone or combined with pharmacotherapy appeared to be safe. More high quality trials with rigorous research methods are needed.