A Double-blind, Randomized, Comparative Study to Evaluate the Efficacy and Safety of Zaleplon versus Zolpidem in Shortening Sleep Latency in Primary Insomnia

Background: Benzodiazepines cause a high proportion of adverse effects while non-benzodiazepinecompounds have demonstrated high efficacy and less adverseeffects in patients with insomnia. The objective of this study was to comparethe effectiveness and safety of non-BZ zaleplon and zolpidem in primaryinsomnia.Methods: This was a randomized, double-blind, active-controlled, double-dummy,comparative study. A total of 48 patients were enrolled, of which 45 patientscompleted the study. Patients who entered the study were required to take thestudy drug orally once daily at bedtime for two weeks. Each patient kept asleep diary and answered a questionnaire. We used these documents to measureand evaluate changes from baseline to Week 2 in sleep latency, durationand quality of sleep, the number of awakenings and incidence of reboundinsomnia.Results: The data revealed a significant decrease in sleep latency from baseline toWeek 2 for patients receiving zaleplon 10 mg and zolpidem 10 mg. Patientsreceiving zaleplon exhibited a marginally greater, but not statistically significant,reduction in sleep latency than those who received zolpidem. There wasno significant difference in the frequency of adverse effects between thezaleplon and zolpidem groups; however, during this clinical trial there wasone lethal event caused by a traffic accident in the zaleplon group.Conclusion: There was no significant difference between zaleplon and zolpidem in theefficacy of reducing sleep latency or adverse effects. A large pharmacovigilancestudy is needed before concluding that either zolpidem or zaleplon isfree from next-day residual effects.