Amitriptyline 25mg falls into a class of drugs known as tricyclic antidepressants. This is used in the treatment of mental/mood disorders such as depression. It works on restoring the balance of neurotransmitters such as serotonin in the brain. Balancing these chemicals in the brain elevates the sense of well-being, improves the mood, lifts depression, clears anxiety and tension, improves sleep and increases energy levels.