List of products in the National Drug Code with proprietary name . This medication is used to treat an overactive bladder. By relaxing the muscles in the bladder, trospium improves your ability to control your urination. It helps to reduce leaking of urine, feelings of needing to urinate right away, and frequent trips to the bathroom. Trospium belongs to a class of drugs known as antispasmodics. It is also known as an antimuscarinic.