Gabapentin for tinnitus: A systematic review

Objective The main aim of this study was to assess the effect of gabapentin on tinnitus via a systematic review. Data Sources An electronic search of literature as well as a hand search was conducted. Study Selection Only double-blind randomised controlled trials (RCTs) that met all of the inclusion criteria were included to this review. Two studies that met the inclusion criteria were included to the review. 14 studies were excluded. Data Extraction The Cochrane Collaboration tool for assessing risk of bias was used for quality assessment of the included studies. Data Synthesis Due to inadequate details in reporting the data in the included studies conducting a meta-analysis was not appropriate. Hence, qualitative synthesis and interpretation of the data was carried out. Conclusions The authors of the both studies reported that gabapentin was not superior to placebo in their primary outcomes. Following the assessment of risk of bias, one of the included studies was judged to be at high risk of attrition bias and reporting bias and the other one was judged to have low risk of bias. There were significant within-study clinical heterogeneities with regard to the baseline Tinnitus Handicap Inventory scores, duration of tinnitus as well as severity of hearing loss in the included trails. This is important because a treatment effective in a specific subgroup of tinnitus may not be detectable when tested in a heterogeneous population. This review concludes that there is insufficient evidence regarding the effect of gabapentin on tinnitus. Key words: Tinnitus, gabapentin, systematic review, hearing impairment