The Purpose of Anticonvulsant Drug Therapy

Anticonvulsant medication is used to treat children who have had seizures and are at risk to have more seizures. There are now a number of drugs available for this purpose and the overall efficacy of anticonvulsant drug therapy is good. With proper use of medication, 75-80% of children with seizures will have significantly reduced numbers of seizures or no seizures. There remain however, 20-25 percent of children with seizures who continue to have seizures despite treatment with medication. Among these patients, some will eventually have some improvement by using different medications (alone or in combination) and different dosages. In such instances, our approach is to give an amount of medication that will bring about the best possible control of seizures, but with a minimum of side effects.

Choice of Drugs

Several factors determine which anticonvulsant drug is chosen for treatment. These factors include: the type of seizure a child has, the age of the child, the individual preference of the physician, and the cost of the medication. The drug chosen is the one predicted to be the most effective and most safe for the patient. A single drug is preferred whenever possible although some children require two or more drugs in combination. We generally prefer to use tablets or capsules rather than the liquid preparations because they allow more accurate dosing and are more convenient than liquids.

How Anticonvulsant Drugs Are Given

When using liquid medication, use a calibrated dropper, medicine syringe or measuring spoon to insure that you are giving your child an accurate amount of medication. Many of the tablets are scored. A scored tablet has a line in the center of it and can be cut in half if needed.

The frequency with which a drug is administered is partly determined by how long it lasts in the body. Drugs that last longer (such as Phenobarbital) can be given once or twice a day. Drugs that are metabolized quickly need to be given more frequently, sometimes 3-4 times a day. The dosing frequency may need to be adjusted for an individual child, since absorption and metabolism are not the same in everyone.

Most children who take medications three times a day do not need to take the medicine at school. The child can take the medicine before school, after school and at bedtime. A drug prescribed twice a day is taken in the morning and atbed time or dinner time. It is not necessary to be absolutely precise about the exact time of day when these medications are administered. Bedtime can be 8 pm or 9:30 pm and it is entirely acceptable for this to vary in a given child from day to day. What is important is that the child receive the total daily dose that is prescribed at spaced intervals.

What You Need To Know About Anticonvulsant Drugs

When your child is prescribed an anticonvulsant medication, you should understand the following: the name of the drug, the number of milligrams (mgs) in the capsule, tablet, or teaspoon of liquid preparation, how often the drug is to be taken, and the common side-effects or toxic effects of the drug or drugs. The types of side-effects include "allergic" and toxic effects. Allergic reactions are unpredictable, usually occur shortly after starting the medication and are not related to the dose of medication. Toxic effects usually result from excessive dosage and high serum levels of the drug. One further concern is the possibility of adverse effects upon the fetus when anticonvulsant drugs are taken during pregnancy. This matter should be discussed with the physician when the woman taking these medications contemplate spregnancy.

Side-effects of anticonvulsant drugs are usually not serious and are reversible once the dose is reduced or the drug is discontinued. Drugs with a relatively high likelihood of more serious side-effects are usually not prescribed unless the safer medications are not effective in controlling the seizures. Accidental ingestion of large quantities of any of these medications by small children can result in severe intoxication or even death. For this reason, all medications should be kept in a safe place, well out of the reach of young children.

The quantity of the drug that is present in the blood (the plasma level) can often be determined by a laboratory test. When control of seizures is less than optimal and the plasma level is found to be below the therapeutic range, the physician can then safely increase the dosage. Determination of the plasma level is also valuable when the child develops symptoms that suggest drug toxicity. Identification of a plasma level in the toxic range in such a child usually indicates a need for reduction of the dosage. How often the plasma level should be obtained on a child taking anticonvulsant drugs is variable and depends on several factors. In those patients on low dosages of a drug whose seizures are well controlled, plasma levels are needed only one to two times per year. Conversely, when a child requires a high dosage, or is on multiple drugs, o rseizures are poorly controlled, plasma level monitoring at frequent intervals is sometimes necessary.

Some anticonvulsant medications have the potential to decrease the white blood cell count. Certain other antiepileptic drugs can affect liver and/or kidney function. While problems with blood counts, liver, or kidney function are rare, blood samples from your child may need to be obtained on a periodic basis to make sure these organs are functioning normally. Whether your child needs to be monitored for any of these problems depends on the medication being taken. If your child becomes ill, be sure that the physician knows what medicines he or she is taking.

All anticonvulsants act through their effect on the brain, since seizures arise from the brain. As a result, any anticonvulsant can lead to changes in personality, behavior or learning ability. There is individual variation in response to a drug. If your child has a significant worsening of behavior or learning that lasts for more than about 4-6 weeks after a new medication is started you should notify the neurologist.

How Long To Continue Drug Treatment

Basically, drug therapy is continued as long as the child remains susceptible to seizures. Many children do "outgrow" their predisposition to have seizures. This is more commonly seen in otherwise normal children, whose electroencephalograms (EEG) have been normal or only mildly abnormal, whose seizures occurred infrequently and were promptly controlled with Drug Therapy. Under such circumstances, the medication is often discontinued after about 2 years without seizures. Other children, for example those with brain injury, may go many years between seizures on drug therapy, but still are clearly susceptible to future attacks and the medication will be continued. In the final analysis,the drug treatment is stopped when it is determined that the child has a relatively low probability of having more seizures. This is never a certainty and is always a judgement matter. In determining when to stop the anticonvulsant, you and the physician will weigh the benefit of stopping a daily medication (with potential side-effects) against the risk of recurrent seizures. When the medication is stopped, the doses are gradually tapered over 2-4 weeks rather than stopped abruptly. Abrupt discontinuation of antiepileptic medication can lead to status epilepticus (prolonged seizures).

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