Fluparoxan (GR-50,360) is a potent and highly selective α2-adrenergic receptor antagonist which was being investigated as an antidepressant but failed to show sufficiently significant efficacy for depression in clinical trials and never made it to the market. In animal and/or human studies fluparoxan has been found to produce stimulation, tachycardia, hypertension, hyperthermia, penile erection, and pro-nociceptive effects, as well as antidepressant-like effects, panic, and anxiogenesis.