RO 15-8081

RO 15-8081 is a novel small molecule that acts as a **mixed serotonin (5-HT) and noradrenaline (norepinephrine) uptake inhibitor**, developed for its potential analgesic (pain-reducing) effects. It has shown potent antinociceptive properties in animal pain models, and in human studies, it has been found to elevate the threshold and tolerance to experimentally induced pain. In clinical trials, RO 15-8081 demonstrated analgesic efficacy for conditions such as osteoarthritis, particularly at higher doses, but its tolerability was limited by side effects such as dry mouth, insomnia, headache, constipation, nausea, dizziness, nervousness, and palpitations. The compound is a substituted cyclohexanol hydrochloride and was developed by Hoffmann-La Roche.