Drug inhibiting release of Ach at myoneural junction is

Ans) a ( Botulinum toxin) Ref Goodman & Gilman 11th ed, KDT 5th ed page 76Two toxins interfere with cholinergic transmission by affecting release. Boutilinum toxin inhibit release, while black widow spider toxin induces massive release and depletion. The site on the presynaptic nerve terminal for block of ACh release by botulinum toxin; death usually results from respiratory paralysis unless patients with respiratory failure receive artificial ventilation.Injected locally, botulinum toxin type A is used in the treatment of certain ophthalmological conditions associated with spasms of ocular muscles (e.g., strabismus and blepharospasm) and for a wide variety of unlabeled uses ranging from treatment of muscle dystonias and palsy to cosmetic erasure of facial lines and wrinklesHemicholinium, a synthetic compound, blocks the transport system by which choline accumulates in the terminals of cholinergic fibers, thus limiting the synthesis of the ACh store available for release.Vesamicol blocks the transport of ACh into its storage vesicles, preventing its release.