Reduction anesthetic agents

ANILINES, BENZYL AMINES, AND ANALOGUES An orally active local anesthetic agent that can be used as an (intiarrhythmic agent is meobenti ne (57). Its patented synthesis starts with -hydroxyphenyl nitrile and proceeds by dimethyl sulfate etherification and Raney nickel reduction to Alkylation of -methyl-dimethylthiourea with completes l.he synthesis of meobenti ne (57). ... 

Whatever the mechanisms responsible for bronchial hyperreactivity, bronchoconstriction itself seems to result not simply from the direct effect of the released mediators but also from their activation of neural or humoral pathways. Evidence for the importance of neural pathways stems largely from studies of laboratory animals. Thus, the bronchospasm provoked in dogs by histamine can be greatly reduced by pretreatment with an inhaled topical anesthetic agent, by transection of the vagus nerves, and by pretreatment with atropine. Studies of asthmatic humans, however, have shown that treatment with atropine causes only a reduction in—not abolition of—the... 

Intravenous anesthetic agents have much less influence on the neuromuscular blocking effects of relaxants and most have no clinically significant effect. However, ketamine (SEDA-14, 113) has been reported to significantly potentiate atracurium (137), and also D-tubocurarine but not pancuronium (138) in man. Animal studies suggest that all relaxants will be potentiated by ketamine in a dose-dependent manner (139,140). It has been suggested that had Johnston et al. (138) used a higher dose of ketamine (than 75 mg/m ), they would have seen potentiation of pancuronium. The main effect of ketamine appears to be a reduction in the sensitivity of the postjunctional membrane to acetylchohne, possibly by ion-channel blockade. Propofol has been reported to potentiate vecuronium-induced and atracurium-induced blocks (141). 

In summary, virtually all anesthetic agents and techniques are associated with reductions in glomerular filtration rate and urine output. These changes are usually readily reversed in the immediate postoperative period and represent the net effect of complex interactions between direct actions of the anesthetics on the kidney and indirect changes in cardiac output, blood pressure, and neuroendocrine function. 

Neuraxial and peripheral anesthetic techniques provide several unique advantages when used in lieu of or in combination with systemic analgesics and anesthetic agents. Regional techniques have been demonstrated to offer reductions in post-operative morbidity and mortality, although the extent of this reduction and applicability to all patient populations remain controversial. Specific benefits offered by regional techniques include decreased intra-operative blood loss, earlier ambulation, improved postoperative pain control, and a decreased incidence of post-operative nausea and vomiting. However, these... 

Thus, acylation of 3(W,iV-dibutylamino)propanol (39) with p-nitrobenzoyl chloride affords the intermediate, 40. Reduction of the nitro group gives butacaine (41), an agent equipotent as cocaine as a topical anesthetic. 

Both chlorine dioxide and chlorite, being strong oxidizing agents, are most likely rapidly reduced in biological systems mainly to chloride ion. Bercz et al. (1982) demonstrated this reduction for chlorine dioxide that was introduced into saliva obtained from anesthetized monkeys. 

Reduction in the anesthetic dose of the most commonly used barbiturate, methohexital, or the use of alternate agents such as ketamine or etomidate... 

Reduction of local or regional blood flow is desirable for achieving hemostasis in surgery, for reducing diffusion of local anesthetics away from the site of administration, and for reducing mucous membrane congestion. In each instance, -receptor activation is desired, and the choice of agent depends on the maximal efficacy required, the desired duration of action, and the route of administration. 

The endothelial toxicity of local anesthetics has been assessed in pigs, as this might be relevant to the safety of agents given by intracameral injection (335). Lidocaine, mepivacaine, and prilocaine were safe, while bupivacaine in clinically effective concentrations resulted in significant cell reduction. 

Metabolism of inhaled anesthetics usually begins with oxidation and is carried out by cytochrome P-450 enzymes located in the microsomes of fhe hver and the kidneys [30, 31]. Under certain circumstances, some agents, such as halothane, might also undergo reduction. In addition to their primary metabolism, some anesthetics, sevoflurane for instance, also undergo phase II conjugation reactions prior to excretion. 

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