4-Aminopyridine
4-Aminopyridine (4-AP, INN fampridine, USAN dalfampridine) is an organic compound with the chemical formula C5H4N–NH2. The molecule is one of the three isomeric amines of pyridine. It is used as a research tool, in characterizing subtypes of the potassium channel. It has also been used as a drug, to manage some of the symptoms of multiple sclerosis, and is indicated for symptomatic improvement of walking in adults with several variations of the disease. It was undergoing Phase III clinical trials as of 2008, and the U.S. Food and Drug Administration (FDA) approved the compound on January 22, 2010. Fampridine is also marketed as Ampyra (pronounced "am-PEER-ah," according to the maker's website) in the United States by Acorda Therapeutics and as Fampyra in Europe. In Canada, the medication has been approved for use by Health Canada since February 10, 2012.