Eszopiclone

Eszopiclone, sold under the brand name Lunesta among others, is a nonbenzodiazepine medication used in the treatment of short-term and long-term insomnia. It is one of the few FDA-approved hypnotic medications with a controlled substance designation that does not have restrictions on its length of use. Evidence supports benefits up to six months, with some studies suggesting similar efficacy after 12 months. It is taken by mouth. Eszopiclone's primary mechanism of action involves enhancing the natural effect of GABA receptors by acting as a positive allosteric modulator on GABA-A expressing neurons. Common side effects include headache, dry mouth, nausea, and dizziness. Severe side effects may include suicidal thoughts, hallucinations, and angioedema. Rapid decreasing of the dose may result in withdrawal. Eszopiclone is classified as a nonbenzodiazepine or Z-drug and a sedative and hypnotic of the cyclopyrrolone group. It is the S-stereoisomer of zopiclone. Approved for medical use in the United States in 2004, eszopiclone is available as a generic medication. In 2020, it was the 232nd most commonly prescribed medication in the United States, with more than 1 million prescriptions. Eszopiclone is not sold in the European Union; as of 2009, the European Medicines Agency (EMA) ruled that it was too similar to zopiclone to be considered a new active substance.