Tetrodotoxin for prolonged local anesthesia with minimal myotoxicity

@article{Padera2006TetrodotoxinFP,
  title={Tetrodotoxin for prolonged local anesthesia with minimal myotoxicity},
  author={Robert F. Padera and Julie Y Tse and Evangelia Bellas and Daniel S. Kohane},
  journal={Muscle \& Nerve},
  year={2006},
  volume={34}
}
Conventional local anesthetics such as bupivacaine cause considerable myotoxicity and neurotoxicity, whereas tetrodotoxin (TTX) does not. Tetrodotoxin combined with bupivacaine or vasoconstrictors produces long‐duration nerve blockade. To assess whether these prolonged blocks can be produced without increased myotoxicity, Sprague‐Dawley rats were injected with bupivacaine, TTX, and both, or TTX plus epinephrine. Median durations of thermal nociceptive blockade were, respectively, 188, 401, 882… 

Tetrodotoxin-Bupivacaine-Epinephrine Combinations for Prolonged Local Anesthesia

Combinations of Tectin in bupivacaine 0.25% with epinephrine 5 µg/mL appear promising for prolonged duration of local anesthesia, and sciatic nerve histology was benign for all groups.

Prolonged Duration Local Anesthesia by Combined Delivery of Capsaicin- and Tetrodotoxin-Loaded Liposomes.

Capsaicin may be useful for its synergistic effects on other formulations even when used in very small, safe quantities and did not cause detectable local or systemic toxicity.

Effect of chemical permeation enhancers on nerve blockade.

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Tetrodotoxin, Epinephrine, and Chemical Permeation Enhancer Combinations in Peripheral Nerve Blockade

CPEs can prolong the duration of nerve blockade across a range of concentrations of TTX and could also be used to reduce the concentration of epinephrine needed to achieve a given degree of nerve block, which may be useful in enhancing nerve blockade from site 1 sodium channel blockers.

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Evaluating the local neural and muscular toxicity of these new formulations containing 0.5% BVC or RVC complexed with HP-&bgr;-CD found that they presented a lower myotoxicity and a similar cytotoxic effect when compared to plain local anesthetic solutions.

Duration and Local Toxicity of Sciatic Nerve Blockade With Coinjected Site 1 Sodium-Channel Blockers and Quaternary Lidocaine Derivatives

Coadministration of site 1 sodium-channel blockers and QLDs greatly prolongs the duration of peripheral nerve block without enhancing local tissue injury, but minimal myotoxicity still persists.

Local Toxicity from Local Anesthetic Polymeric Microparticles

Lidocaine and bupivacaine PLGA microspheres resulted in similar degrees of myotoxicity, irrespective of drug loading, and Caution is warranted in the use of such devices near muscle and nerve.

Local Myotoxicity from Sustained Release of Bupivacaine from Microparticles

Whereas the release vehicles themselves were not myotoxic, both burst and extended release of bupivacaine were, and a possible implication is that myotoxicity is an inevitable concomitant of sustained release of local anesthetics.
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