Indiplon: A Nonbenzodiazepine Sedative–Hypnotic for the Treatment of Insomnia

Abstract

To review the pharmacology, pharmacokinetics, pharmacodynamics, efficacy data, and adverse effects of indiplon in the treatment of transient and chronic insomnia in adult and geriatric patients. A literature search was conducted using MEDLINE (1966-May 2008), International Pharmaceutical Abstracts (1970-May 2008), and Cochrane database (2007) for the key words indiplon or NBI-34060. References cited in the articles were reviewed for additional information. Abstract data were included only in the absence of significant published data. English-language literature reporting animal and human clinical studies was reviewed to evaluate data on the pharmacology, pharmacokinetics, pharmacodynamics, efficacy, and adverse effects of indiplon. Clinical trials selected for inclusion were limited to those with human subjects, with the accepted inclusion of pharmacology data in animals. Indiplon is a nonbenzodiazepine sedative-hypnotic that exhibits its sedating activity through its interaction with the gamma-aminobutyric acid alpha receptor complex. Indiplon immediate-release (IR) as well as modified-release (MR) forms have shown improvement compared with placebo in patients with DSM-IV-TR primary insomnia in various areas of subjective and objective sleep measurements. Specifically, improvements in total sleep time, latency to persistent sleep, latency to sleep onset, wake after sleep onset, and sleep quality have been noted in clinical trials. Trials evaluating both indiplon IR and MR have so far not identified any major serious adverse effects. Limited clinical trial data exist on use of indiplon in a "true" transient insomnia patient population. Based on recent Food and Drug Administration requests, clinical trial data assessing direct comparisons of indiplon IR with other approved nonbenzodiazepine sedative-hypnotics are needed to clearly define the differences among these agents.