Phenothiazine is a chemical compound that belongs to a class of medications primarily used to treat psychiatric disorders, such as schizophrenia and severe anxiety. It works by blocking certain neurotransmitters in the brain, particularly dopamine, which helps to reduce symptoms like hallucinations and agitation. In addition to its psychiatric uses, phenothiazine derivatives are also employed in treating nausea and vomiting, as well as in veterinary medicine for calming animals. Some common examples of phenothiazine medications include chlorpromazine and promethazine, each with specific applications and side effects.