BOTOX BLOCKS NEUROMUSCULAR TRANSMISSION BY BINDING TO ACCEPTOR SITES ON MOTOR OR
SYMPATHETIC NERVE TERMINALS, ENTERING THE NERVE TERMINALS, AND INHIBITING THE RELEASE OF
ACETYLCHOLINE. THIS INHIBITION OCCURS AS THE NEUROTOXIN CLEAVES SNAP-25, A PROTEIN INTEGRAL TO
THE SUCCESSFUL DOCKING AND RELEASE OF ACETYLCHOLINE FROM VESICLES SITUATED WITHIN NERVE ENDINGS.
WHEN INJECTED INTRAMUSCULARLY AT THERAPEUTIC DOSES, BOTOX PRODUCES PARTIAL CHEMICAL
DENERVATION OF THE MUSCLE RESULTING IN A LOCALIZED REDUCTION IN MUSCLE ACTIVITY. IN ADDITION, THE
MUSCLE MAY ATROPHY, AXONAL SPROUTING MAY OCCUR, AND EXTRAJUNCTIONAL ACETYLCHOLINE RECEPTORS
MAY DEVELOP. THERE IS EVIDENCE THAT REINNERVATION OF THE MUSCLE MAY OCCUR, THUS SLOWLY REVERSING MUSCLE DENERVATION PRODUCED BY BOTOX WHEN INJECTED INTRADERMALLY, BOTOX PRODUCES TEMPORARY CHEMICAL DENERVATION OF THE SWEAT GLAND RESULTING IN LOCAL REDUCTION IN SWEATING.