Serotoninergic drugs have been shown to be effective in the treatment of OSA in animals, including the English bulldog, using serotonin antagonists and reuptake inhibitors (such as trazodone), serotonin precursors, and 5-HT3 blockers (such as ondansetron) [127,128]. This evidence concerns the gene HTR3A and obstructive sleep apnea syndrome.