Results of the first human trial indicate that a novel site 1 sodium channel blocker belonging to the class of paralytic shellfish toxins can substantially prolong the duration of sensory blockade. The substance, neosaxitoxin belongs to a class of natural neurotoxic alkaloids known as the paralytic shellfish toxins. In nature, neosaxitoxin is produced by algae blooms, but the compound is now being manufactured from bioreactor-grown algae by the Chilean-based company Proteus SA. Trial spokesperson Carolina Donado, MD, stated “Neosaxitoxin has prolonged local anesthesia when given either alone or with bupivacaine or epinephrine, while reducing the risk of systemic toxicity.”
The characteristic of prolonged blockade should give neosaxitoxin advantages over current anesthetics, especially in settings where high volumes of local anesthetic are required, and could help avoid the adjunctive use of systemic opioids, which can lead to longer hospitalizations, and the need for perineural catheter infusions to prolong the anesthetic effect. Commenting on the trial results, Alan R. Bielsky, MD, assistant professor at the University of Colorado School of Medicine, observed that a new anesthetic compound was welcome in the clinical armamentarium. He additionally called for further study of the performance of neosaxitoxin in the perineural space, its effect on motor function, ability to administer in the neuraxial space, and utility in targeting ectopic activity in neuropathic pain.
Read a news story about the findings here.