The anticonvulsants, also called antiepileptic drugs (abbreviated "AEDs"), belong to a diverse group of pharmaceuticals used in prevention of the occurrence of epileptic seizures. More and more, anticonvulsants are also finding ways into the treatment of bipolar disorder, since many seem to act as mood stabilizers. The goal of an anticonvulsant is to suppress the rapid and excessive firing of neurons that start a seizure. Failing this, a good anticonvulsant would prevent the spread of the seizure within the brain and offer protection against possible excitotoxic effects that may result in brain damage. However, anticonvulsants themselves have been linked to lowered IQ.

The major molecular targets of marketed anticonvulsant drugs are voltage-gated sodium channels; components of the GABA system, including GABAA receptors, the GAT-1 GABA transporter, and GABA transaminase; and voltage-gated calcium channels.

Some anticonvulsants have shown antiepileptogenic effects in animal models of epilepsy. That is, they either prevent the expected development of epilepsy or can halt or reverse the progression of epilepsy. However, no drug has shown this effect in human trials.

Approval

The usual method of achieving approval for a drug is to show it is effective when compared against placebo, or that it is more effective than an existing drug. In monotherapy (where only one drug is taken) it is considered unethical by most to conduct a trial with placebo on a new drug of uncertain efficacy. This is because untreated epilepsy leaves the patient at significant risk of death. Therefore, almost all new epilepsy drugs are initially approved only as adjunctive (add-on) therapies. Patients whose epilepsy is currently uncontrolled by their medication (i.e., it is refractory to treatment) are selected to see if supplementing the medication with the new drug leads to an improvement in seizure control. Any reduction in the frequency of seizures is compared against a placebo. |1988 | |- |carbamazepine |Tegretol |1974-07-151974-07-15 |1965 |- |clobazam |Frisium | |1979 |1974 | | |- |divalproex sodium |Depakote |1983-03-101983-03-10 | | |- |ethosuximide |Zarontin |1960-11-021960-11-02 |1955 | | |- |felbamate |Felbatol |1993-07-291993-07-29 | | |- |fosphenytoin |Cerebyx |1996-08-051996-08-05 | | |- |gabapentin |Neurontin |1993-12-301993-12-30 |1993-05May 1993 |1991-10October 1991 |2000-09-292000-09-29 |2000-09-292000-09-29 | | |- |metharbital |Gemonil |1952 | | |- |methsuximide |Celontin |1957-02-081957-02-08 | | |- |methazolamide |Neptazane |1959-01-261959-01-26 | | |- |oxcarbazepine |Trileptal |2000-01-142000-01-14 |2000 | | |- |pregabalin |Lyrica |2004-12-302004-12-30 |2004-07-062004-07-06 |2004-07-062004-07-06 |1952 |2001-12-052001-12-05 |1998 |1995 | | |- |valproic acid |Depakene/Convulex |1978-02-281978-02-28 |1993 |2005-03-102005-03-10 |2005-03-102005-03-10 |}

See also

• ATC code N03

References

• Drug Reference for FDA Approved Epilepsy Drugs
• Epilepsy Action: UK Anti-Epileptic Drugs List

External links

• eMedicine: Antiepileptic Drugs: an overview
• NINDS: Anticonvulsant Screening Program
• Use of Anticonvulsants in Pharmacotherapy of Bronchial Asthma
• MDNG: Anticonvulsants and Bone Health