Organothiophosphates or organophosphorothioates are a subclass of organophosphorus compounds. Many of these compounds are used as pesticides, some have medical applications, and some are used as oil additives. They generally have the chemical formula (RO)3PS, −, R(RO)2PS, etc.Echothiophate used for treatment of glaucomaAmifostine, which is used in cancer chemotherapyChlorpyrifos, a common insecticideMalathion, a common insecticidePhosphorothioates are the basis for antisense therapies Organothiophosphates or organophosphorothioates are a subclass of organophosphorus compounds. Many of these compounds are used as pesticides, some have medical applications, and some are used as oil additives. They generally have the chemical formula (RO)3PS, −, R(RO)2PS, etc. Oligonucleotide phosphorothioates (OPS) are modified oligonucleotides where one of the oxygen atoms in the phosphate moiety is replaced by sulfur. These compounds are the basis of antisense therapy, e.g., the drugs fomivirsen (Vitravene), Oblimersen, Alicaforsen, and Mipomersen (Kynamro).