Methods and compositions for studying, imaging, and treating pain

Abstract

Saxitoxin analog compounds, compositions, pharmaceutical compositions, methods of synthesis of saxitoxin analogs, methods of imaging, methods of treatment, including methods of treating pain, are provided. Saxitoxin (STX), gonyautoxin (GTX), and zetekitoxin, and variant STX compounds bind to sodium channels and are effective to reduce or block flow of sodium ions through such channels. Such channel block affects nerve and muscle action, and may be effective to reduce or block pain sensations, relax muscles, reduce muscle spasm, and reduce wrinkles. STX analog binding to sodium channels may also be useful to locate, image, or mark sodium channels, and so be useful in studying sodium channels and sodium channel disorders, and in the diagnosis and treatment of patients suffering from sodium channel disorders. In embodiments, the variant STX compounds include conjugates having increased serum half-life as compared to STX when administered to a subject. In embodiments, the present disclosure provides a method for alleviating pain in a subject in need of treatment, the method comprising administering to the subject an effective amount of a saxitoxin analog compound, or a pharmaceutically acceptable salt, isomer, tautomer or prodrug thereof, whereby pain in said subject is alleviated.