Anticonvulsants Health Article

Definition

Anticonvulsants are a class of drugs indicated for the treatment of various types of seizures associated with seizure disorders such as epilepsy, a neurological dysfunction in which excessive surges of electrical energy are emitted in the brain, and other disorders.

Some anticonvulsants are indicated for other medical uses. Some hydantoins, such as phenytoin, are also used as skeletal muscle relaxants and antineuralgics in the treatment of neurogenic pain. Some anticonvulsants and antiepileptic drugs (AEDs) are used in psychiatry for the treatment of bipolar disorders (manic-depression).

Purpose

Although there is no cure for the disorder, anticonvulsants are often effective in controlling the seizures associated with epilepsy. The precise mechanisms by which many anticonvulsants work are unknown, and different sub-classes of anticonvulsants are thought to exert their therapeutic effects in diverse ways. Some anticonvulsants are thought to generally depress central nervous system (CNS) function. Others, such as GABA inhibitors, are thought to target specific neurochemical processes, suppress excess neuron function, and regulate electrochemical signals in the brain.

Description

There are several sub-classes and types of anticonvulsants. They are marketed in the United States under a variety of brand names.

• Barbiturates, including Mephobarbital (Mebaral), Pentobarbital (Nembutal), and Phenobarbital (Luminol, Solfoton).
• Benzodiazepines, including Chlorazepate (Tranxene), Clonazepam (Klonopin), and Diazepam (Valium).
• GABA Analogues, including Gabapentin (Neurontin) and Tiagabine (Gabitril).
• Hydantoins, including Ethotoin (Peganone), Fosphentyoin (Mesantoin), and Phenytoin (Dilantin).
• Oxazolidinediones, including Trimethadione (Tridione).
• Phenyltriazines, including Lamotrigine (Lamictal).
• Succinamides, including Ethosuximide (Zarontin), Methsuximide (Celontin), and Phensuximide (Milontin).
• Other anticonvulsants, including Acetazolamide (Diamox), Carbamazepine (Carbatrol, Tegretol), Felbamate (Felbatol), Levetiracetam (Keppra), Oxcarbazepine (Trileptal), Primidone (Mysoline), Topiramate (Topamax), Valproic acid (Depakene, Depakote), and Zonisamide (Zonegran).

A physician prescribes anticonvulsant medication, or a combination of anticonvulsant medications, according to seizure type and pattern in individual patients. Some anti-convulsant medications are not appropriate for pediatric patients under 16 years of age.

Recommended dosage

Anticonvulsants are available in oral suspension (syrup), injectable, capsule, tablet, and sprinkle forms, depending on the type of medication. Not all anticonvulsants will be available in all forms. Anticonvulsants are prescribed by physicians in varying daily dosages, depending on the age, weight, and other health concerns of the individual patient, as well as the severity and frequency of their seizures.

It is important to follow the prescribing physicians directions carefully as each individual anticonvulsant medication has its own recommended daily dosages and dose schedule. Some anticonvulsants are taken in a single daily dose; others are taken in divided, multiple daily doses. A double dose of any anticonvulsant medication should not be taken. If a dose is missed, it should be taken as soon as possible. However, if it is within four hours of the next scheduled dose, the missed dose should be skipped. Taking an anticonvulsant at regular intervals and at the same time each day enables consistent levels of the medication to be maintained in the bloodstream, and results in more effective seizure control.

In general, initiating any course of treatment which includes anticonvulsants requires a gradual dose-increasing regimen. Adults and children typically take a smaller daily dose for the first two weeks. Daily dosages of anti-convulsant medication may then be slowly titrated, or increased over time until adequate seizure control is achieved using the lowest dose possible.

When ending a course of treatment of anticonvulsant, physicians typically taper the patient's daily dose over a period of several weeks. Suddenly stopping treatment including anticonvulsants may cause seizures to return or occur with greater frequency. Patients taking anticonvulsants drugs for the treatment of pain or bipolar disorders may experience also have seizures, even if they have never had them before, if they suddenly stop taking the medication.