tailieunhanh - Drugs and Poisons in Humans - A Handbook of Practical Analysis (Part 38)

Introduction: Muscle relaxants can be classified into the peripheral-and central-acting drug types ( Table ). The drugs of the peripheral type are also called neuromuscular blocking agents. The peripheralacting muscle relaxants are being used for muscle relaxation upon endotracheal intubation and/or general anaesthesia for surgical operation. The central-acting muscle relaxants are used for treatments of painful muscle contracture caused by locomotorial disorders, and for relaxation of muscle stiffness caused by psychotic tension or by neurosis. The cases of poisoning by the peripheralacting muscle relaxants often take place, because of its strong suppressive action on respiration. However, their poisoning is rare. | Muscle relaxants by Mayumi Nishikawa and Hitoshi Tsuchihashi Introduction Muscle relaxants can be classified into the peripheral-and central-acting drug types Table . The drugs of the peripheral type are also called neuromuscular blocking agents. The p eripheral-acting muscle relaxants are being used for muscle relaxation upon endotracheal intubation and or general anaesthesia for surgical operation. The central-acting muscle relaxants are used for treatments of painful muscle contracture caused by locomotorial disorders and for relaxation of muscle stiffness caused by psychotic tension or by neurosis. The cases of poisoning by the peripheralacting muscle relaxants often take place because of its strong suppressive action on respiration. However their poisoning is rare at the scene of medical treatments because the risk is usually avoided by artificial respiration. Most of poisoning incidents due to the peripheral-acting muscle relaxants are intentional and or homicidal. In this chapter therefore analytical methods only for the peripheral-acting muscle relaxants Table are dealt with. Since these drugs are quaternary ammonium salts special care should be taken for their stability and efficient extraction 1 . TLC analysis Reagents and its preparation Tubocurarine chloride suxamethonium chloride succinylcholine chloride and pancuronium bromide can be purchased from Sigma St. Louis MO USA . For vecuronium bromide pure powder is not commercially available ampoule solution for medical use O Table Classification of muscle relaxants muscle relaxants peripheral-acting non-depolarizing type tubocurarine chloride alkaloid type pancuronium bromide and vecuronium bromide other types depolarizing type suxamethonium chloride choline type central-acting chlorphenesin carbamate phenprobamate and methocarbamol carbamate type chlorzoxazone chlorzoxazone type chlormezanone dantrolene sodium pridinol mesilate afloqualone eperisone hydrochloride tolperisone .