Vigabatrin Valproate

Drug therapy includes the use of anticonvulsant or anti-epileptic drugs, such as sodium valproate, sodium phenytoin, lamotrigine, vigabatrin. 

Should certain antiepileptic drugs be contraindicated in patients with active psychosis Unfortunately there is not enough solid information to answer this question. Undoubtedly, anticonvulsants that are less likely to cause psychosis (lamotrigine, carbamazepine, oxcarbaze-pine, valproate) should be preferred (52,53). However, patients with psychoses have been successfully treated even with drugs that are believed to be associated with psychosis, such as vigabatrin. For example, in a prospective study in 10 patients with psychosis and epilepsy to whom vigabatrin was added, there was no aggravation of the psychiatric disorder (54). 

Individual drugs carbamazepine, phenytoin, sodium valproate, lamotrigine, vigabatrin, gabapentin, clonazepam, topiramate, levetiracetam. 

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). 

Alopecia is not uncommon with valproate, and it can also occasionally occur with phenjdoin, carbamazepine, vigabatrin, and gabapentin. 

Of 20 consecutive patients treated with vigabatrin 12 had visual field constriction, severe in four and sjmpto-matic in two (33). Visual field defects were more common in patients who were also taking valproate. Although most reports concerned adults, children may also be affected (34). 

Arndt CF, Salle M, Derambure PH, Defoort-Dhellemmes S, Hache JC. The effect on vision of associated treatments in patients taking vigabatrin carbamazepine versus valproate. Epilepsia 2002 43(8) 812-17. 

In an early clinical study, tiagabine was reported to have no significant effect on the plasma levels of carbamazepine, phenytoin, valproate, and vigabatrin. Similarly, tiagabine (titrated from 8 mg up to a maximum of 48 mg daily over 18 days) did not alter the steady-state pharmacokinetics of phenytoin or carbamazepine in 12 patients with epilepsy. However, in another similar study, it reduced the AUC of valproate by 10%, but this reduction is not expected to be elinieally significant. ... 

No pharmacokinetic interaction appears to occur between vigabatrin and valproate, but one retrospective study found a correlation between valproate levels and vigabatrin levels. 

Antiepileptic drug-induced encephalopathies have been reviewed [50 ]. These complications have been reported with phenytoin, carbamazepine, and valproate and less often with vigabatrin, lamotrigine, and topiramate. 

Metabolism Valproate reduces free and total carnitine concentrations in children. In a cross-sectional study in 91 children, the effects of some new antiepileptic drugs (vigabatrin, n = 24 lamotrigine, = 28 and topiramate) on serum carnitine concentrations have been studied 18 children taking valproate served as positive controls [314 ]. Carnitine concentrations were unaffected by the new drugs. 

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