Fowler's solution is a solution containing potassium arsenite that once was prescribed as a remedy or a tonic. A Dr. Fowler of Stafford, England proposed its use in 1786 as a substitute for a patent medicine, "tasteless ague drop." It was prescribed in the United States until the late 1950s for a range of ailments including malaria, chorea, and syphilis.
Fowler's solution, also known as "Liquor Potassii Arenitis," Kali Arsenicosum or Kali arseniatum, is a 1% solution of potassium arsenite, KH2AsO3. Because of the poisonous and carcinogenic nature of arsenic compounds, Fowler's solution is dangerous. Documented side effects of treatment with Fowler's solution include: cirrhosis of the liver, idiopathic portal hypertension, urinary bladder cancer, skin cancers.
In 2001 the U.S. FDA approved a proprietary formula of a solution of arsenic trioxide for acute promyelocytic leukaemia.[1]