Phenobarbital Gabapentin

Antacids Gabapentin Phenobarbital Phenytoin Reduced effect of the object drugs Reduced absorption of the object drugs... 

Phenobarbital Phenytoin Topiramate Valproate Oxcarbazepine Topiramate Second-line Clobazam6 Gabapentin Levetiracetam Phenytoin Tiagabine... 

Carbamazepine, phenytoin, phenobarbital, valproate, gabapentin, lamotrigine, levetiracetam, tiagabine, topiramate, zonisamide... 

Valproic acid may cause less cognitive impairment than phenytoin and phenobarbital. Some of the newer agents (e.g., gabapentin and lamotri-gine) have been shown to cause fewer cognitive impairments than the older agents (e.g., carbamazepine). Topiramate may cause substantial cognitive impairment. 

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

Bromide (1857) was the first drug to be used for the treatment of epilepsy, but it is now obsolete. Phenobarbital, introduced in 1912, controlled patients resistant to bromides. The next success was the discovery in 1938 of phenytoin (a hydantoin) which is structurally related to the barbiturates. Since then many other drugs have been discovered, but phenytoin still remains a drug of choice in the treatment of major epilepsy. Over the past ten years there has been a dramatic increase in the number of new anticonvulsant drugs (vigabatrin, gabapentin, lamotrigine, topiramate, oxcarbazepine, levetiracetam), but none has been shown to be superior to the major standard anticonvulsants (phenytoin, carbamazepine and sodium valproate). 

Tiagabine has an elimination half-Ufe of 7 to 9 hours. In patients receiving CyP 3A4 inducing anti-epileptic drugs (AEDs), the elimination half-life decreases to 4 to 7 hours. Phenytoin, phenobarbital, and carbamazepine are CyP 3A4 inducers. Valproic acid and gabapentin are not. Tiagabine is not considered to be a CyP 3A4 inducer. ... 

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]. 

Barbiturates phenobarbital, secobarbital Benzodiazepines alprazolam, diazepam, lorazepam, triazolam Others buspirone, zolpidem BZ receptor antagonist flumazenil Carbamazepine, ethosuximide, valproic acid, phenytoin, clonazepam, diazepam, lorazepam, gabapentin... 

Gabapentin does not normally affect the pharmacokinetics of car-bamazepine, phenytoin, phenobarbital or sodium valproate, and no dosage adjustments are needed on concurrent use. However, isolated reports describe increased phenytoin levels and toxicity in two patients given gabapentin. 

Gabapentin does not affect phenobarbital levels, nor is it affected by pbenobarbital. Other studies confirm that the steady-state pharmacokinetics of carbamazepme and sodium valproate are unaffected by gabapentin, and that the pharmacokinetics of gabapentin are similarly unaffected by these antiepileptics. ... 

There is some evidence that the enzyme-inducing antiepileptics (carbamazepine, phenobarbital, phenytoin and primidone) may modestly reduce levetiracetam levels, but this is not thought to be clinically relevant. Levetiracetam does not usually alter the levels of these antiepileptics. However, some studies have found modestly raised phenytoin levels, and cases of possible carbamazepine toxicity have also been reported. There appears to be no pharmacokinetic interaction between levetiracetam and gabapentin, lamotrigine, or valproate. 

Furthermore, evidence from clinical studies suggests that levetiraeetam does not affect the serum levels of gabapentin, lamotrigine, phenobarbital, or primidone. In general therefore, no dosage adjustments would seem to be needed if levetiraeetam is used as add-on therapy with any of these drugs. 

There appears to be no pharmacokinetic interaction between pregabalin and carbamazepine, gabapentin, lamotrigine, phenobarbital, phenytoin, topiramate, valproate, alcohol, lorazepam, or oxycodone. However, the impairment of cognitive and gross motor function caused by oxycodone was additive with pregabalin, and pregabalin may potentiate the effects of alcohol and lorazepam. 

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