Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Tinnitus loudness
RCT	40 people In review	Proportion of people with improvement in tinnitus (measured by tinnitus synthesiser and visual analogue scale [scale of 0–10; increasing score is associated with increasing loudness]) 12 weeks 13/17 (77%) with alprazolam (initially 0.5 mg/night) 1/19 (5%) with placebo	Significance not assessed The RCT used dose adjustment of alprazolam but no dose adjustment of placebo, potentially biasing the results because of a difference in the attention given to people in the 2 groups
RCT Crossover design	36 people	Proportion of people with improvement in tinnitus (measured by tinnitus matching and reported as a change in dB sensation level) 18 weeks From 8.7 to 8.6 (–0.1) with alprazolam 0.5 mg three times daily (on escalating scale to minimise adverse effects) From 8.4 to 8.4 (0) with placebo	P value not reported Reported as not significant		Not significant
General tinnitus symptoms
RCT Crossover design	36 people	Mean change in Tinnitus Handicap Injury (THI) score 18 weeks From 43.9 to 42.8 (–1.1) with alprazolam 0.5 mg three times daily (on escalating scale to minimise adverse effects) From 49.6 to 49.2 (–0.4) with placebo	P value not reported Reported as not significant		Not significant
RCT Crossover design	36 people	Proportion of people with improvement in tinnitus (visual analogue scale 1–100, higher score = more severe) 18 weeks From 76.0 to 55.1 (–20.9) with alprazolam 0.5 mg three times daily (on escalating scale to minimise adverse effects) From 70.1 to 68.6 (–1.5) with placebo	P <0.001	Effect size not calculated	alprazolam