Asendin is part of the Tricyclic Antidepressants class and treats Depression and Anxiety. Tricyclic antidepressants are used to treat depression, obsessive-compulsive disorder, insomnia, bed wetting, itching, and eczema. They work by increasing the amount of norepinephrine and serotonin in the brain to elevate mood, slow down brain activity, and relieve itching. Asendin is only available as a brand name drug.