Triptans used to treat migraine headaches; medicines used to treat mood, anxiety, psychotic or thought disorders, including tricyclics, lithium, SSRIs, SNRIs, buspirone, or antipsychotics; tramadol, mephenytoin
(Mesantoin) or over-the-counter supplements such as tryptophan or St.
A novel transversion in the intron 5 donor splice junction of CYP2C19 and a sequence polymorphism in exon 3 contribute to the poor metabolizer phenotype for the anticonvulsant drug s mephenytoin
Identification of new human CYP2C19 alleles (CYP2C19*6 and CYP2C19*2B) in a Caucasian poor metabolizer of mephenytoin
Once the metabolism of dextromethorphan was established to cosegregate with that of debrisoquin and other prototype substrates of CYP2D6, it was unanimously accepted as an attractive alternative to the other phenotyping probes (15) because of its recognized safety, its worldwide availability, and its specificity to CYP2D6 since no co-inheritance between mephenytoin
and dextromethorphan metabolism was found in human subjects.
Common CYP450 2D6 and 2C19 drugs, which patients" metabolize differently CYP2D6 CYP2C19 Antiarrhythmics Amitriptyline (in part) Antidepressants Certain barbiturates Beta-blockers Proguanil Neuroleptics Citalopram Others Cyclophosphamide -Atomoxetine Diazepam -Codeine Imipramine -Ondansetron Mephenytoin
Classification and Pharmacologic Management of Seizures Seizure First Line Agents New/Alternative Agents Simple Partial phenytoin primidone carbamazepine phenobarbital valproic acid gabapentin lamotrigine felbamate topiramate ethotoin mephenytoin
Complex partial phenytoin primidone carbamazepine valproic acid phenobarbital mephobarbital gabapentin lamotrigine felbamate topiramate amobarbital Absence clonazepam methsuximide ethosuximide phensuximide valproic acid lamotrigine trimethadione Myoclonic valproic acid clonazepam Tonic Clonic phenytoin/fosphenytoin phenobarbital carbamazepine primidone valproic acid topiramate Stares epilepticus phenytoin/fosphenytoin diazepam lorazepam phenobarbital diazepam secobarbital pentobarbital
The first PM of mephenytoin
, a probe drug for CYP2C19, was reported by Kupfer et al in 19792.
The first-generation AEDs known to cause birth defects and other developmental toxicities include the hydantoins (ethotoin [Peganone], fosphenytoin [Cerebyx], mephenytoin
[Mesantoin], and phenytoin [Dilantin]), phenobarbital, primidone (Mysoline), carbamazepine (Tegretol), and valproic acid derivatives (Depakene, Depakote).
For instance, CYP2A6 is responsible for the main metabolism of nicotine, and CYP2C19 is responsible for mephenytoin
Metabolic polymorphism assessed by hydroxylation of debrisoquine and mephenytoin
Other drugs assayed at therapeutic concentrations that had no interference included carbamazepine and its epoxide and hydroxy metabolites, oxcarbazepine and it monohydroxylated metabolite, zonisamide, levetiracetam, phenytoin and its metabolites, felbamate, lamotrigine, clonazepam, phenobarbital, primidone, acetaminophen, salicylate, ibuprofen, amitriptyline, nortriptyline, desipramine, doxepin and nordoxepin, imipramine, valproic acid, topiramate, mephenytoin
and Nirvanol, amiodarone and desethylamiodarone, methsuximide and normethsuximide, ethotoin, clozapine, and sertraline.
Hydroxylation polymorphisms of debrisoquine and mephenytoin
in European populations.