Doxepin is a medication classified as a tricyclic antidepressant, which also possesses sedative properties. It is used in the treatment of depression, anxiety disorders, insomnia, and related conditions. Doxepin works by increasing the availability of certain neurotransmitters in the brain, such as serotonin and norepinephrine, which helps improve mood and alleviate symptoms of depression. Additionally, due to its sedative properties, Doxepin may also be prescribed to treat insomnia.