RT Book, Section
A1 Burnett, Michelle
A2 Freeman, Brian S.
A2 Berger, Jeffrey S.
SR Print(0)
ID 1102567022
T1 Barbiturates
T2 Anesthesiology Core Review: Part One Basic Exam
YR 2014
FD 2014
PB McGraw-Hill Education
PP New York, NY
SN 9780071821377
LK accessanesthesiology.mhmedical.com/content.aspx?aid=1102567022
RD 2024/04/18
AB Barbiturates  are  derivatives  of  barbituric  acid.  The  presence  of  oxygen  in  the  pyrimidine  nucleus  at  carbon  2  position  makes  the  drug  an  oxybarbiturate  (eg,  methohexital).  In  contrast,  thiobarbiturates  (eg,  thiopental)  have  a  sulfur  atom  at  the  carbon  2  position.  Substitutions  at  carbon  5  position  with  either  aryl  or  alkyl  groups  produce  hypnotic  and  sedative  effects.  Phenyl  groups  enable  the  potent  anticonvulsant  activity.  Thiamylal  and  thiopental,  both  thiobarbiturates,  have  similar  pharmacological  profiles  and  are  available  as  racemic  mixtures.  Methohexital  is  marketed  as  a  racemic  mixture  of  two  alpha  isomers.  The  beta-1  stereoisomer  form  of  methohexital  produces  excessive  motor  responses.