Thawongit S.Siripornpanich V.Thampratankul L.Mahidol University2026-02-062026-02-062026-03-01Neuropsychopharmacology Reports Vol.46 No.1 (2026)https://repository.li.mahidol.ac.th/handle/123456789/114534Kleine–Levin syndrome (KLS) is a rare disorder with limited literature on treatment options and efficacy, especially in adolescents. We report a 12-year-old patient with KLS who had a favorable response to clarithromycin therapy. In this unique case of KLS, both central hypopneas and a novel manifestation of REM sleep without atonia (RSWA) emerged during the episode and resolved with clarithromycin, suggesting a modulatory role on brainstem sleep networks and a possible neurophysiologic effect of clarithromycin therapy. However, reactions to pharmacologic treatment in individual KLS cases remain highly variable. Therefore, we compiled and summarized the available evidence to assist clinicians in evaluating potential therapeutic options.Pharmacology, Toxicology and PharmaceuticsPsychologyMedicineArticleSCOPUS10.1002/npr2.700872-s2.0-1050265870832574173X41491632