To the Editor.—
In the March issue of the Archives (107:427, 1973), I noted in the article entitled "Photosensitive Dermatitis Due to Pyritinol" authored by three doctors from Tokyo that "pyritinol is a compound of two molecules of pyridoxine bounded (sic) through S-S-linkage . . ." and that it was used in the treatment of cerebral arteriosclerosis. Because this was all I could find about the drug in the article and because I knew nothing more about it, I searched through (1) AMA Drug Evaluations, ed 1, 1971; (2) American Drug Index, 1973; (3) Physician's Desk Reference, ed 27, 1973; (4) The Pharmacological Basis of Therapeutics, ed 4, 1970; and (5) Modern Drug Encyclopedia, ed 12, 1973. Much to my disappointment, I could not find the drug listed in any of these publications.I concluded, therefore, that the drug is not well-known in the United States, and consequently, I would like