Atoxyl

ATOXYL, Atoxylum, NH₂·C₆H₄·AsO·OH·ONa + 4H₂O, the sodium salt of para-aminophenylarsonic acid, is a white crystalline powder, odorless, with a salty taste, easily soluble in water and almost insoluble in alcohol. The arsenic content in Atoxyl is 24.1%. Aqueous solutions of Atoxyl decompose upon boiling, releasing arsenic acid. In the animal organism, Atoxyl decomposes slowly, making it less toxic than arsenious acid. Atoxyl was introduced into therapy by Blumenthal in 1902. In 1905, English authors pointed out the etiotropic properties of Atoxyl in trypanosomal diseases, and in 1907, Robert Koch applied it with brilliant success in the fight against sleeping sickness. Experimental studies (Uhlenhuth, Hoffmann, Roscher) proved that Atoxyl acts specifically on trypanosomes; therefore, Atoxyl was applied in experimental syphilis, and subsequently in humans suffering from syphilis or relapsing fever.

Most of the Atoxyl in the body circulates with the blood, remaining undecomposed for a long time, and is partially excreted in this form from the body with the urine. A certain portion of Atoxyl is retained in the cells of the body and undergoes changes there, forming highly toxic products that affect the central nervous system and cause ataxia and paresis, and particularly often optic nerve atrophy and nephritis. Such severe toxic action of Atoxyl, along with milder side effects (dizziness, headache, tinnitus, hearing impairment, appetite disorders, etc.), was the reason that in therapy Atoxyl began to be replaced by other similar preparations that are less toxic, parasitotropic rather than organotropic, whereas initially the indications for the use of Atoxyl were very numerous: psoriasis, furunculosis, anaemia, chorea, epilepsia, lues, trypanosomatosis, febris intermittens, and others. In heart diseases, Atoxyl is contraindicated. Methods of administration: from 0.04 to 0.2 of Atoxyl in a 20% solution subcutaneously or intramuscularly, sometimes intravenously; orally in pills of 0.05–0.15 of Atoxyl per dose.