RT Book, Section
A1 Bauer, Larry A.
SR Print(0)
ID 1106303880
T1 Phenobarbital/Primidone
T2 Applied Clinical Pharmacokinetics, 3e
YR 2015
FD 2015
PB McGraw-Hill Medical
PP New York, NY
SN 9780071794589
LK accesspharmacy.mhmedical.com/content.aspx?aid=1106303880
RD 2024/04/19
AB Phenobarbital  is  a  barbiturate  and  primidone  is  a  deoxybarbiturate  effective  in  the  treatment  of  generalized  tonic-clonic  and  partial  seizures  (Table  13-1).1,2,3,  and  4  Phenobarbital  is  available  as  a  separate  agent,  but  is  also  an  active  metabolite  produced  via  hepatic  metabolism  during  primidone  treatment.  Because  of  this,  and  because  they  share  a  similar  antiseizure  spectrum,  these  two  drugs  are  considered  together  in  this  chapter.  The  probable  mechanism  of  action  for  phenobarbital  is  elevation  of  seizure  threshold  by  interacting  with  γ-aminobutyric  acidA  (GABAA)  postsynaptic  receptors  which  potentates  synaptic  inhibition.5,6  While  the  exact  mechanism  of  action  is  not  known  for  the  antiepileptic  effect  of  primidone,  a  portion  of  its  antiseizure  activity  is  due  to  its  active  metabolites  phenobarbital  and  phenylethylmalonamide  (PEMA).6,7