Copyright © 1996, 1997, 2001 by Galen
Daryl Knight and VitaleTherapeutics, Inc.
Phenathiazine Drugs as Toxic Flavin Analogues?
The toxicity observed for analogues of riboflavin
gives cause for concern about other compounds
containing a tricyclic ring system, such as the phenathiazine-based
drugs. These compounds have been used as tranquilizers, as anti-spasmodics,
as anti-histamines, as anti-psychotics, as sedatives, as anti-tussives,
as antiemetic, as anti-pruritics, as ataractics, as anticholinergic, as
urinary antiseptics, as insecticides, and even as wormers (anti-helmintics)
by continuously feeding them to livestock. Perhaps through its homology
with flavin (lumiflavin shown for comparison, below left), phenothiazine
(below right) can produce toxic reactions in the liver, photodynamic reactions,
hemolytic anemia, abdominal cramps, tachycardia, and other as yet unconfirmed