The duration of sensory blockade was significantly prolonged by a novel site 1 sodium channel blocker that belongs to the class of paralytic shellfish toxins, now being manufactured from bioreactor-grown algae.

The duration of sensory blockade was significantly prolonged by a novel site 1 sodium channel blocker that belongs to the class of paralytic shellfish toxins, now being manufactured from bioreactor-grown algae.

Anesthesiologynews.com reports that the first-in-human trial of an algal compound used for anesthetic purposes was reported at the American Society of Anesthesiologists 2014 annual meeting in New Orleans and was named the “Best Clinical Abstract.”

“Neosaxitoxin has prolonged local anesthesia when given either alone or with bupivacaine or epinephrine, while reducing the risk of systemic toxicity,” said Carolina Donado, MD, of Boston Children’s Hospital and Harvard Medical School.

Neosaxitoxin belongs to a class of natural neurotoxic alkaloids known as the paralytic shellfish toxins, explained senior investigator Charles B. Berde, MD, PhD, professor of anesthesia (pediatrics) at Harvard Medical School. 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.

In healthy volunteers, neosaxitoxin significantly prolonged the time to partial and complete recovery when administered with the other agents. Duration of effect exceeded 24 hours for some parameters.

This characteristic of prolonged blockade should give neosaxitoxin advantages over current anesthetics, especially in settings where high volumes of local anesthetic are required, according to Dr. Berde, who said this would 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.

“With combination formulations using site 1 sodium channel blockers, we can provide local anesthesia for periods of several days with a single injection before or during surgery,” he predicted.

Alan R. Bielsky, MD, assistant professor at the University of Colorado School of Medicine, and director of the Acute Pain Service at Children’s Hospital Colorado in Aurora, commented for Anesthesiology News. “The [potential] appearance of neosaxitoxin as a local anesthetic adjuvant is an exciting addition to regional anesthesia and science as a whole. In historical terms, our most recent addition to classic local anesthetics was in 1996 with the introduction of ropivicaine, proving that new compounds are overdue,” he said.

Dr. Berde acknowledged the involvement of Dan Kohane, MD, PhD, in the compound’s development and in facilitating Boston Children’s Hospital’s collaboration with Proteus SA.