Monoamine oxidase inhibitors (MAOIs, such as linezolid, methylene blue, etc), increase the risk of serotonin syndrome, a mild to life-threatening build up of serotonin in the system. Similarly, venlafaxine can interact with other agents that affect serotonin in the brain, such as tricyclic antidepressants, certain pain medications, supplements that contain St. John’s Wort or tryptophan. Be prepared to share all prescription and over the counter medications, as well as any other products you take, with your provider.