Comfortably Numb with Neosaxitoxin

Neosaxitoxin, a new local anesthetic derived from algae, resulted in less pain following surgery, and patients recovered about two days sooner than those given the common local anesthetic, bupivacaine.

Based on this finding, researchers at Children's Hospital, Boston, have moved into a collaboration agreement with biotech start-up Proteus SA to usher the anesthetic into clinical practice.

Patients who undergo surgery and receive local anesthetic generally need opioid analgesics to cope with pain after the 8-hour effects of the anesthetic wear off. These painkillers can induce side effects such as nausea, vomiting, sedation, shallow breathing and constipation, sometimes prolonging hospital stays.

Neosaxitoxin (neoSTX) lasts for about 24 hours. Its use resulted in considerably less pain following surgeries in which 137 Chilean patients underwent laparoscopic removal of their gall bladders. More neoSTX-treated patients had complete absence of pain at 12 hours, both at rest (88 vs. 69 percent) and with movement (80 vs. 60 percent) compared to patients who were given bupivacaine. The Neosaxitoxin patients experienced a full recovery about 2 days earlier than those who were not treated with neo-STX.

No serious adverse reactions were reported in either group.

Potential risks associated with local anesthetic include nerve damage, resulting in prolonged anesthesia (numbness) and paresthesia (tingling, feeling of "pins and needles").