Trazodone for the treatment of insomnia: a meta-analysis of randomized placebo-controlled trials

To assess the efficacy and tolerability of trazodone compared with placebo in patients with insomnia. Electronic databases were searched and relevant reports were hand-screened to identify eligible trials. Only randomized placebo-controlled trials were included. Standardized mean differences (SMD) and the odds ratios (OR) were estimated using a random-effect model. Primary efficacy outcomes included sleep efficiency (SE%) and self-reported sleep quality (SQ). Secondary efficacy outcomes included sleep latency (SL), total sleep time (TST), the number of awakenings (NAs), waking time after sleep onset (WASO). Tolerability outcome was measured by the number of patients who discontinued for adverse events and acceptability outcome was measured by the number of patients who discontinued for all causes. Seven trials involving 429 patients were included. There was no significant improvement for trazodone in SE% (SMD = 0.09, 95% confidence interval (CI) −0.19 to 0.38, P = 0.53) with a non-significant heterogeneity (I2 = 0%, P = 0.59). However, patients receiving trazodone perceived better SQ than those receiving the placebo (SMD = −0.41, 95% CI −0.82 to −0.00, P = 0.05) with a non-significantly moderate heterogeneity (I2 = 65%, P = 0.06). As to secondary efficacy outcomes, we only found a significant reduction for trazodone in NAs (SMD = −0.51, 95%CI −0.97 to −0.05) compared to the placebo, with non-significant differences found in SL, TST, or WASO between trazodone and placebo. Moreover, no significant difference was found in the outcome of tolerability or acceptability. Trazodone was effective in sleep maintenance by decreasing the number of early awakenings and it could significantly improve perceived sleep quality, although there were no significant improvements in sleep efficiency or other objective measures. Trazodone however, presented good tolerance in the short-term treatment of insomnia.