Paroxetine. Molecular model of the drug paroxetine ( C19.H20.F.N.O3), a selective serotonin reuptake inhibitor used for treating major depression, obsessive-compulsive disorder, panic disorder, social anxiety, posttraumatic stress disorder, and generalized anxiety disorder. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white), nitrogen (blue), oxygen (red) and fluorine (yellow).