Hyoscyamine is a medication derived from the belladonna plant, commonly used to treat various gastrointestinal disorders. It works by relaxing the muscles in the gut, which helps alleviate symptoms like cramping and spasms. Hyoscyamine is often prescribed for conditions such as irritable bowel syndrome (IBS) and peptic ulcers. In addition to its gastrointestinal uses, hyoscyamine can also help manage symptoms of Parkinson's disease and reduce excessive salivation. It belongs to a class of drugs known as anticholinergics, which block the action of a neurotransmitter called acetylcholine, leading to decreased secretions and muscle contractions.