saxitoxin and Hypesthesia

Topics: Adult; Anesthesia, Local; Bupivacaine; Dose-Response Relationship, Drug; Double-Blind Method; Drug Therapy, Combination; Epinephrine; Humans; Hypesthesia; Pain; Pain Measurement; Saxitoxin; Treatment Outcome; Young Adult

Neosaxitoxin (NeoSTX) is a site-1 sodium channel blocker that produces prolonged local anesthesia in animals and humans. Under a Food and Drug Administration-approved phase 1 Investigational New Drug trial, the authors evaluated safety and efficacy of NeoSTX alone and combined with 0.2% bupivacaine (Bup) with and without epinephrine.. The authors conducted a double-blind, randomized, controlled trial involving healthy male volunteers aged 18 to 35 yr receiving two 10-ml subcutaneous injections. Control sites received Bup. In part 1, active sites received (1) 5 to 40 μg NeoSTX+Saline (NeoSTX-Saline), (2) 5 to 40 μg NeoSTX+Bup (NeoSTX-Bup), or (3) placebo (Saline). In part 2, active sites received 10 or 30 μg NeoSTX+Bup+Epinephrine (NeoSTX-Bup-Epi) or placebo. Primary outcome measures were safety and adverse events associated with NeoSTX. Secondary outcomes included clinical biochemistry, NeoSTX pharmacokinetics, and cutaneous hypoesthesia.. A total of 84 subjects were randomized and completed the two-part trial with no serious adverse events or clinically significant physiologic impairments. Perioral numbness and tingling increased with NeoSTX dose for NeoSTX-Saline and NeoSTX-Bup. All symptoms resolved without intervention. NeoSTX-Bup-Epi dramatically reduced symptoms compared with other NeoSTX combinations (tingling: 0 vs. 70%, P = 0.004; numbness: 0 vs. 60%, P = 0.013) at the same dose. Mean peak plasma NeoSTX concentration for NeoSTX-Bup-Epi was reduced at least two-fold compared with NeoSTX-Saline and NeoSTX-Bup (67 ± 14, 134 ± 63, and 164 ± 81 pg/ml, respectively; P = 0.016). NeoSTX-Bup showed prolonged cutaneous block duration compared with Bup, NeoSTX-Saline, or placebo, at all doses. Median time to near-complete recovery for 10 μg NeoSTX-Bup-Epi was almost five-fold longer compared with Bup (50 vs. 10 h, P = 0.007).. NeoSTX combinations have a tolerable side effect profile and appear promising for prolonged local anesthesia.

Topics: Adult; Anesthesia, Local; Anesthetics, Local; Bupivacaine; Dose-Response Relationship, Drug; Double-Blind Method; Drug Therapy, Combination; Epinephrine; Humans; Hypesthesia; Male; Pain Measurement; Saxitoxin; Young Adult

Since January 1, 2002, human illness after eating pufferfish caught in waters near Titusville, Florida, has been reported (Figure 1). The illnesses were manifested by neurologic symptoms consistent with exposure to paralytic shellfish toxins. Laboratory analysis in early April confirmed the presence of saxitoxin in uneaten pufferfish. This report presents selected case examples and summarizes all cases reported to the Toxic Exposure Surveillance System of the American Association of Poison Control Centers (TESS).

Topics: Adult; Aged; Female; Florida; Foodborne Diseases; Humans; Hypesthesia; Male; Middle Aged; Paresthesia; Peripheral Nervous System Diseases; Saxitoxin; Seafood; Tetraodontiformes; Virginia

As of May 15, 2002, a total of 13 presumptive cases of saxitoxin poisoning were reported in Florida residents who ate pufferfish caught in waters near Titusville, Florida. Five cases were reported in April, and eight cases were identified through increased surveillance by Florida poison control centers, hospital emergency departments (EDs), and county health departments. This report updates the investigation of these cases.

Topics: Florida; Foodborne Diseases; Humans; Hypesthesia; Paresthesia; Peripheral Nervous System Diseases; Saxitoxin; Seafood; Tetraodontiformes