γ-Aminobutyric Acid and Derivatives Reduce the Incidence of Acute Pain after Herpes Zoster - A Systematic Review and Meta-analysis

Abstract

Herpes zoster (HZ) causes considerable pain and distress, and γ-Aminobutyric acid (GABA) and its derivatives are assumed to control this, but the available data are inconsistent. This meta-analysis and systematic review aimed to assess the effectiveness of GABA derivatives in the prevention of acute herpetic pain. The metaanalysis was conducted following the PRISMA guidelines using PICO format, registered in PROSPERO number CRD42018095758. PubMed, Web of Science, Ovid, Scopus, and EMBASE databases were searched. Records were included if they were randomized controlled trials of patients undergoing HZ infection, investigating the effect of GABA derivatives versus placebo in the treatment of HZ pain. Eligible trials were evaluated for the risk of bias. Then data were extracted and analysed. The number of patients with observed presence of pain after treatment was used to calculate odds ratio in a random effect model with the DerSimonian-Laird estimator. The I2 statistic was analysed for heterogeneity. The potential risk of bias was measured using Egger's regression test. The meta-analysis included three randomized controlled trials with a total of 297 patients. The incidence of acute HZ pain events for GABA group was significantly lower compared to placebo group,18/148 vs 44/149, respectively (OR = 0.36; 95% CI = 0.14 to 0.93; Z = 2.11; P = 0.035), Egger's test yielded P = 0.308. In conclusion, the present meta-analysis demonstrates that GABA derivatives reduce the incidence of acute herpetic pain. However, additional, well-designed randomized clinical trials are needed to determine their dose- and time-dependency regarding this symptom.

Keywords: Acute herpes zoster pain; Egger's test; GABA; herpes zoster associated pain; meta-analysis; γ-aminobutyric acid.

Fig. (1)

PRISMA 2009 flow diagram for identification of relevant studies.

Fig. (2)

Risk of Bias Assessment summary: review authors’ judgements about each methodological quality item presented in different aspect from each included study. (A higher resolution / colour version of this figure is available in the electronic copy of the article).

Fig. (3)

Forest plot of comparison I: GABA or its derivatives vs placebo, primary outcome measurement. The presence of PHN after treatment. . Note: Odd ratio (OR), Confident Interval (CI). (A higher resolution / colour version of this figure is available in the electronic copy of the article).

Fig. (4)

Forest plot of comparison II: GABA or its derivatives vs placebo, secondary outcome measurement. The presence of adverse events during treatment. Note: Odd ratio (OR), Confident Interval (CI). (A higher resolution / colour version of this figure is available in the electronic copy of the article).