Doxepin is a medication classified as a tricyclic antidepressant (TCA) with notable 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 help improve mood and relieve symptoms of depression. Due to its sedative effects, Doxepin may also be prescribed for managing insomnia.