Anticonvulsants
                                ===============
þ DEPAKOTE (DEPAKENE, valproate, valproic acid)
 - can load IV
  + 25 mg/kg for full load
  + originally recommended 20 mg/min max rate, but can safely give up to
    100-150 mg/min (3-4 mg/kg/min)
  + no problem with arrhythmias, or sedation
  [Venkataraman V, Wheless JW. Safety of rapid intravenous infusion of
  valproate loading doses in epilepsy patients. Epilepsy Res
  1999;35(2):147-53. IV valproate may be given to patients requiring rapid
  elevation of serum valproate or for patients unable to take oral medication.
  Previously we established the loading dose of IV valproate needed to achieve
  serum concentrations of > 100 ug/ml. This study evaluated the safety of
  rapid infusion of valproate to achieve high therapeutic levels. Twenty-four
  infusions of IV valproate were carried out electively in twenty-one patients
  with epilepsy (ages 2-54 years). The dose ranged from 21-28 mg/kg (mean 24.2
  mg/kg). Target infusion rates were 3 or 6 mg/kg per min, yielding an
  infusion duration of 4.17 or 8.34 min. ECG was monitored; blood pressure was
  measured before and after infusion. Post infusion serum valproate
  concentrations were 64-204.1 ug/ml (mean 132.6). There were no significant
  changes in blood pressure and no ECG abnormalities observed. Transient pain
  occurred at the site of injection in five patients, associated with redness
  in two. This appeared to related to the concentration of valproic acid in
  the infusion fluid. We conclude that a loading dose of IV valproate can be
  administered safely and rapidly. This finding enables further studies
  evaluating IV valproate as a non-sedative anticonvulsant in the management
  of status epilepticus.]

þ Dilantin (phenytoin)
  <Dilantin.TXT>

þ Zonegran (zonisamide)
 - high risk of heatstroke, especially in kids (reported 1:10,000
   patient-years in Japan, reported 12:10,000 patient-years in the U.S.)

þ Keppra (levetiractam)
 - unrelated to other antiseizure medications
 - secondary drug, use with others
 - used for recalcitrant seizures

þ Trileptal (oxcarbazepine):
 - similar to carbamazepine
 - 1200-2400 mg/day

þ Valium (diazepam)
  <Valium.TXT>

þ Versed (midazolam):
  <Versed.TXT>

þ Oral Loading:
  <D-Load.TXT>

  See Also:  Seizures             <N-Seizur.TXT>

þ Porphyria
 - 10% of patients with an attack of acute porphyria present with
   seizures.  What two commonly used anticonvulsants are
   contraindicated?  What treatment is "probably safe"?
   Phenytoin and phenobarbital are contraindicated in patients
   with porphyria.  However, intravenous diazepam is "probably
   safe" and has been used effectively.
   Reference: Schwartz 3rd ed. p 2130

þ Anticonvulsants and Migraine
 - "Pharmacotherapy: A Pathophysiologic Approach, 1997 states phenytoin,
   carbamazepine, and valproic acid may be usful, especially there is an
   association with epilepsy. Apparently, valproic acid has been effective for
   migraine prophylaxis more generally. Rebound headache may occur, so
   compliance is important. Here's the reference cited:
   [Welch KMA. Drug therapy for migraine. New Engl J Med. 1993;329(20):
   1476-1483.]
   --Tina Denetclaw, Pharm.D. BCPS