Atoxil

ATOXIL, Atoxylum, /NH, C,H.

+4H.O, \AsO.OH.ONa sodium salt of para-amidophenylarsinic acid, a white crystalline powder, odorless, with a salty taste, easily soluble in water and almost insoluble in alcohol. Arsenic content in A. is 24.1%. Aqueous solutions of atoxil decompose upon boiling with the release of arsenic acid. In animal organisms, A. decomposes slowly, consequently being less toxic than arsenious acid. A. was introduced into therapy by Blumenthal in 1902. In 1905, English authors pointed out the etiotropic properties of A. in trypanosomiasis, and in 1907, R. Koch successfully used it in the fight against sleeping sickness. Experimental research (Uhlenhuth, Hoffmann, Roscher) proved that A. acts specifically on trypanosomes, therefore A. was used in experimental syphilis, and then in humans suffering from syphilis or relapsing fever.

Most of A. circulates in the blood for a long time without decomposing, and partly in this form is excreted from the body with urine. Some of A. is retained in the body cells and there undergoes changes, forming highly toxic products that affect the central nervous system and cause ataxias and pareses, especially frequently atrophy of the optic nerve and inflammation of the kidneys. Such a severe toxic effect of atoxil, along with milder side effects (dizziness, headache, ringing in the ears, hearing impairment, loss of appetite, etc.), led to the replacement of atoxil in therapy with other similar but less toxic, parasitotropic rather than organotropic drugs, whereas initially the indications for the use of A. were very numerous: psoriasis, furunculosis, anaemia, chorea, epilepsy, lues, trypanosomatosis, febris intermittens, etc. A. is contraindicated in heart diseases. Methods of administration: from 0.04 to 0.2 A. in a 20% solution subcutaneously or intramuscularly, sometimes intravenously; orally in pills of 0.05-0.15 A. per dose.