Gabapentin Felbamate

For simple and complex partial seizures and secondary generalized tonic-clonic seizures, the first line drugs are - carbamazepine, valproate and phenytoin. Second line drugs include - acetazolamide, clobazam, clonazepam, ethosuximide, felbamate, gabapentin, lamotrigine, levetiracetam, oxacarbamazepine, primidone, tiagabine, topiramate and vigabactin. 

Devinsky O, Vasquez B, Luciano D. New antiepileptic drugs for children Felbamate, gabapentin, lamotri-gine, and vigabatrine. J Child Neurol 1994 9(Suppl) S33-45. 

Importantly, Loscher et al. found that carbamazepine, felbamate, gabapentin, lamotrigine, phenobarbital, and topiramate are substrates of ABCBl (P-gp) [38]. Crowe et al. also studied the transport of a variety of antiepileptic drugs including vigabatrin, gabapentin, phenobarbitone, lamotrigine, phenytoin, carbamazepine, and acetazolamide in colorectal tumor-derived Caco-2 cell monolayers. They found that only one antiepileptic, acetazolamide, is a weak ABCBl substrate [39]. 

Table IV-1 -3 summarizes the mechanisms, indications for use, and potential toxic effects of some i newer anticonvulsants. Those listed are felbamate, gabapentin, lamotrigine, tiagabine, topiramate, and j...

Newer anticonvulsants listed are felbamate, gabapentin, and lamotrigine. 

Newer agents Felbamate, gabapentin, lamotrigine, tiagabine, topiramate, vigabatrin ... 

It would seem therefore that no dosage adjustments are normally needed if gabapentin is added to treatment with most of these antiepileptics. However, if gabapentin is added to pbenytoin it may be wise to bear the possibility of raised pbenytoin levels in mind. For mention that gabapentin may prolong the half-life of felbamate, see Felbamate + Gabapentin , p.540. For mention of the lack of interaction between levetiracetam and gabapentin, see Levetiracetam + Other antiepileptics , p.543. 

Carbamazepine, ethosuximide, felbamate, gabapentin, lamotrigine, levitiracetam, oxcarbazine, pregabilin, topiramate, valproic acid, zonisamide... 

Changes in body weight associated with anticonvulsants have been reviewed (116), including the effects of the antiepileptic drugs that have been most commonly associated with this adverse effect (valproic acid, carbamazepine, vigabatrin, and gabapentin) (117). Unlike most anticonvulsants, topiramate, felbamate, and zonisamide can cause weight loss. 

Neither vigabatrin nor gabapentin caused porphyrin accumulation in chicken embryo cultured liver cells, whereas felbamate, lamotrigine, and tiagabine were por-phyrinogenic in this model (129). For gabapentin, safety in porphyrias has been confirmed in preliminary clinical observations (SEDA-19, 70) (SEDA-20, 62). 

Partial seizures Carbamazepine Phenytoin Lamotrigine Valproic acid Oxcarbazepine Gabapentin Topiramate Levetiracetam Zonisamide Tiagabine Primidone, phenobarbital Felbamate... 

Gabapentin Felbamate Interaction poorly documented relevance doubtful Perhaps reduced renal clearance of felbamate... 

A review of the second-generation anticonvulsants reveals that screening or serendipity led to the development of felbamate (10), 1am-otrigine (11), zonisamide (13), topiramate (15), and levetiracetam (16) on the other hand, clobazam (4d) and oxcarbazepine (12) were developed by structural variation of known agents (78). Only three, vigabatrin (8), gabapentin (9), and tiagabine (14), were developed by mechanism-based rational development (78). 

Drug Interactions. Felbamate inhibits the clearance and increases the serum concentration of phenytoin, valproic acid, and phenobar-bital. The concentration of carbamazepine decreases in patients on concmrent therapy with felbamate secondary to enzyme induction however, the concentration of the 10,11 -epoxide metabolite increases. It is recommended that the dose of phenytoin, carbamazepine, and valproic acid be decreased by about 30% when felbamate is added. Felbamate does not appear to interact with either gabapentin or 1am-otrigine. Phenytoin and carbamazepine are enzyme inducers and have been shown to increase the clearance of felbamate. Interactions with warfarin also have been reported. ... 

Barbiturates phenobarbital 1 Benzodiazepines alprazolam, diazepam, i lorazepam, oxazepam Carbamazepine, ethosuximide, valproic acid, phenytoin, diazepam, lorazepam, gabapentin, lamotrigine, felbamate, topiramate, tiagabin, vigabatrin... 

B. Other useful laboratory studies include electrolytes, glucose, creatinine (gabapentin, topiramate), CBC (felbamate), liver transaminases, bilirubin (fel-bamate), and ECG monitoring (lamotrigine). 

There is some evidence that the half-life of felbamate may be prolonged by gabapentin. 

Hussein G, Troupin AS, Montouris G. Gabapentin interaction with felbamate. Neurology... 

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