Eszopiclone, sold under the brand name Lunesta among others, is a medication used in the treatment of insomnia. Evidence supports slight to moderate benefit up to six months. It is taken by mouth.
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. It works by interacting with the GABA receptors.
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 1million 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.