Thiopental

Thiourea (H2NCNH2) reacts with diethyl malonate and its alkyl derivatives in the same way that urea does Give the structure of the product obtained when thiourea is used instead of urea in the synthesis of pentobarbital The anesthetic thiopental (Pentothal) sodium is the sodium salt of this product yWhat IS the structure of this compound ... 

In this experiment the enantiomers of cyclobarbital and thiopental, and phenobarbital are separated using MEKC with cyclodextran as a chiral selector. By adjusting the pH of the buffer solution and the concentration and type of cyclodextran, students are able to find conditions in which the enantiomers of cyclobarbital and thiopental are resolved. 

Although most anesthetics are achiral or are adininistered as racemic mixture, the anesthetic actions are stereoselective. This property can define a specific, rather than a nonspecific, site of action. Stereoselectivity is observed for such barbiturates as thiopental, pentobarbital, and secobarbital. The (3)-enantiomer is modestly more potent (56,57). Additionally, the volatile anesthetic isoflurane also shows stereoselectivity. The (3)-enantiomer is the more active (58). Further evidence that proteins might serve as appropriate targets for general anesthetics come from observations that anesthetics inhibit the activity of the enzyme luciferase. The potencies parallel the anesthetic activities closely (59,60). 

Barbiturates. The ultrashort-acting barbiturates (see Table 1) methohexital (4), thiopental (5), and thiamylal (6) are used for induction and... 

The potential for normal brain tissue injury is one of the limiting factors in the use of XRT for brain tumors. Pentobarbital is a cerebral radioprotectant in rodent and primate models after single doses, but is associated with significant risks. Of alternative barbiturates, thiopental given to tats receiving 70-Gy (7000-rad) whole-brain irradiation in a single fraction enhances the 30-day survival similarly to pentobarbital, whereas ethohexital and phenobarbital show no radioprotective activity (250). 

Figure 11.19 SPME-CE analysis of urine samples (a) blank urine (a) directly injected and extracted for (b) 5 (c) 10 and (d) 30 min (b) Urine spiked with barbiturates, extracted for (e) 30 and (f, g) 5 min. Peak identification is as follows 1, pentobaitibal 2, butabarbital 3, secobarbital 4, amobarbital 5, aprobarbital 6, mephobarbital 7, butalbital 8, thiopental. Concenti ations used are 0.15-1.0 ppm (e, f) and 0.05-0.3 ppm (g). Reprinted from Analytical Chemistry, 69, S. Li and S. G. Weber, Determination of barbiturates by solid-phase microexti action and capillary electrophoresis, pp. 1217-1222, copyright 1997, with permission from the American Chemical Society.

The other method used is infusion of intravenous anaesthetics such as propofol, etomidate (for induction) and the barbiturates such as thiopental and pentobarbital. Investigations into the mechanism of anaesthesia have made use of all these compounds in order to identify a common mode of action linked to likely mechanisms within the CNS. 

Ultrashort-acting (eg, tiiiamylal [Surital], thiopental [Pentodial]). The ultrashort-acting barbiturates are used as anestiietics (see Chap. 35). Single doses have a duration of 20 minutes or less. 

Methohexital (Brevital) and thiopental (Ffentothal), which are ultrashort-acting barbiturates, are used for ... 

D Thiopental "Hycomed Penthiobarbital Sodique GB Intraval (May Baker) ... 

The ultra-short-acting barbiturates include methohexital sodium (Brevi-tal) and thiopental sodium (Pentothal). These agents are used as anesthetics and are administered intravenously. Barbiturates with short-to-intermediate duration of action are used for their sedative-hypnotic effect in the treatment of anxiety. These medications include amobarbital (Amytal), butabarbital (Butisol), sodium pentobarbital (Nembutal), and secobarbital (Seconal). 

Hypnotics. Common hypnotics are thiopental, propofol, midazolam, etomidate, ketamine and inhaled anesthetics. The incidence of hypersensitivity reactions with thiopental is rare. Recently, thiopental was involved in less than 1% of allergic reactions in France [9]. Ever since Cremophor EL, used as a solvent for some non-barbiturate hypnotics, has been avoided, many previously reported hypersensitivity reactions have disappeared. In the last French surveys, reactions to propofol accounted for less than 2.5% of allergic reactions, and reactions to midazolam, etomidate or ketamine appear to be really rare [9]. Finally, no immune-mediated immediate hypersensitivity reaction involving isoflurane, desflurane or sevoflurane has been reported despite their wide use. 

Second tier Reduction of Thiopental 1-5 g IV loading Continuous EEG Keep Systemic... 

The production of free radicals has been implicated in the mechanism of liver injury due to a number of drugs and toxins. These include adtiamycin (Pritsos et al., 1992), halothane (Neuberger and Williams, 1984), phenobar-bital and thiopental (Kanazawa and Ashida, 1991), carbon tetrachloride (Williams and Burk, 1990), 1,1,2,2-tetrachloroethane (Paolini aal., 1992), and paraquat and related bipyridylium compounds (Togashi a al., 1990 De Gray etal., 1991 Kanazawa and Ashida, 1991 Petty etal., 1992). 

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