What condition is Silenor (doxepin) primarily used to treat?

Silenor, which is a brand name for doxepin, is primarily used to treat sleep disturbances, specifically for insomnia. Doxepin is a tricyclic antidepressant that, at lower doses, has been found effective in promoting sleep and improving sleep maintenance. It works by antagonizing certain receptors in the brain, which decreases wakefulness and increases the duration of sleep. While it does have applications in treating depression and anxiety disorders, its approval as Silenor is specifically for insomnia, making sleep disturbances the correct focus for its primary use.

In the context of the other options, while doxepin can treat depression and anxiety, that is not its primary application under the brand Silenor. Additionally, it is not used for chronic pain as a first-line treatment; rather, there are more effective medications for such conditions. This establishes the clarity around the specific and intended use of Silenor (doxepin) in managing sleep-related issues, distinguishing it from other potential applications of the same drug.