Anticonvulsants topiramate/gabapentin/carbamazepine

Other agents with anticonvulsant properties that may be of use m the treatment of bipolar disorder include topiramate, gabapentin, tiagabine and carbamazepine (Janicak et al., 2001). 

For maintenance treatment, failure of first-line mood stabilizers or second-line atypical antipsychotics to control symptoms adequately may lead to monotherapy trials with other anticonvulsants such as carbamazepine, lamotrigine, gabapentin, and topiramate (third-line monotherapy). 

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. 

Anticonvulsants Carbamazepine, valproic acid, gabapentin, topiramate... 

Anticonvulsants. Several antiseizure medicines have been studied in the treatment of PTSD, and some results have been encouraging. Open label studies, first with carbamazepine (800-1200 mg/day) and later with valproate (500-2000 mg/ day), demonstrated overall improvement in PTSD patients, though not for intrusive recollections per se. Recent open label studies of gabapentin, lamotrigine, tiagabine, and topiramate have suggested these anticonvulsants might also be helpful for some PTSD symptoms. 

Another group of mood-stabilizing drugs that are also anticonvulsant agents have become more widely used than lithium. These include carbamazepine and valproic acid for the treatment of acute mania and for prevention of its recurrence. Lamotrigine is approved for prevention of recurrence. Gabapentin, oxcarbazepine, and topiramate are sometimes used to treat bipolar disorder but are not approved by FDA for this indication. Aripiprazole, chlorpromazine, olanzapine, quetiapine, risperidone, and ziprasidone are approved by FDA for the treatment of manic phase of bipolar disorder. Olanzapine plus fluoxetine in combination and quetiapine are approved for the treatment of bipolar depression. 

To review the mechanism of action of lithium and five anticonvulsants used as mood stabilizers (valproic acid, carbamazepine, lamotrigine, gabapentin and topiramate). 

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). 

Other anticonvulsants frequently prescribed to autistic patients include topira-mate, gabapentin, and carbamazepine (Oswald and Sonenklar, 2007). Evidence from controlled studies for the use of these agents for treatment of autistic symptoms other than seizures is not available, although results from open studies with topiramate (Canitano, 2005 Hardan et al., 2004) suggest that this drug is worthy of further investigation. A placebo-controlled trial of oxcarbazepine in childhood autism is underway (clinicaltrials.gov). 

The anticonvulsant action of valproate may prevent ECT treatment from being effective by preventing seizure activity. This is also a theoretical/practical concern with carbamazepine, gabapentin, lamotrigine, and topiramate. As a rule of thumb, the co-administration of an anticonvulsant and ECT should be considered very cautiously ... 

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