Antiepileptic drugs are drugs that are used to treat epilepsy. What are the types of antiepileptic drugs and how do they work? How to choose the right drug for a given patient? Can antiepileptic drugs be used during pregnancy? What are the side effects of taking anti-epileptic drugs?

Antiepileptic drugsare designed to minimize the likelihood of an epilepsy attack, and if it does occur, reduce its intensity.

Epilepsy is a neurological disease in which electrical impulses are not transferred between nerve cells. The neurons responsible for epilepsy are structured in the same way as normal neurons. The difference is that their bioelectric properties are "broken". This causes discharges that begin in different parts of the brain. Most often in the frontal or temporal lobes, with a lower frequency in the occipital and parietal lobes.

Antiepileptic drugs given to patients can work in two ways:

  • can stabilize the cell membranes of neurons (i.e. nerve cells) to counteract the spread of impulses
  • or restore the balance between excitatory and inhibitory neurotransmitters

How is the cell membrane stabilized? By blocking, usually sodium, ion channels or by influencing the activity of the sodium-potassium pump, which is located in the cell membrane. This process leads to the fact that neurons are unable to depolarize. They also do not pass on information to each other because they do not have the ability to induce an action potential.

The effect of drugs restoring the balance of neurotransmitters is to increase the amount of GABA - it is a natural substance that is a neurotransmitter that stops the impulse conduction.

It should be remembered, however, that the occurrence of one, isolated seizure does not immediately necessitate the administration of drugs. However, if there is a likelihood of disease recurrence, and this can be assessed by brain MRI or EEG, drug treatment may be necessary.

How to choose the right AEDs?

Antiepileptic drugs should bealways selected individually for each patient, and the doctor after an interview including questions about: age, sex, all comorbidities, currently taken medications and supplements, and after carrying out tests such as blood counts, liver tests and kidney profile, electrolytes and glucose levels blood and general he alth checks, may introduce drug treatment.

During treatment, you should also systematically monitor these parameters and react to any disturbing changes.

For epilepsy, the patient is initially given the lowest dose of the drug and then gradually increased. This is true until your seizures are controlled. Such a procedure prevents fluctuations in the level of the drug in the body and allows to prevent side effects.

There may be seizures despite increasing the dose. In such situations, the dose is increased by the doctor until it turns out to be effective and the patient tolerates it well.

When this does not help, the doctor most often decides to change the drug to another one from the first line.

Second-line drugs are only introduced if the earlier ones do not help and the patient cannot function normally.

First-line and second-line drugs in epilepsy and additional drugs

First-line medications

  • topiramate
  • lamotrygina
  • valproic acid
  • carbamazepine

Second-line medications

  • gabapentyna
  • pregabalina
  • tiagabina
  • phenytoin
  • lewetiracetam
  • klobazam

Other drugs

  • acetazolamide
  • primidon
  • fenobarbital
  • klonazepam

Antiepileptic drugs must always be taken systematically. You must not reduce or increase the doses yourself, and do not stop the treatment. In order to achieve the most optimal dose of the drug in the body, blood levels of antiepileptic drugs should be systematically controlled.

If symptoms of toxicity are present and the treatment is ineffective due to drug resistance or the patient's neglect of the doctor's prescription, it will be advisable to determine the level of drugs in the blood.

How do you recognize symptoms of toxicity? These include, first of all, gastrointestinal disorders, as well as disturbances of consciousness.

Antiepileptic drugs and pregnancy

Women with epilepsy who may or want to become pregnant must be informed about disease-related and medication useantiepileptic drugs, an increased risk of serious birth defects.

A pregnancy registry has been in place in the UK since 1996 for all pregnant women taking antiepileptic drugs.

The data show that serious birth defects are most common in the offspring of patients receiving valproic acid and those receiving combination therapy.

Read also:

  • Pregnancy with epilepsy

Classification of antiepileptic drugs

  • dibenzoazepine derivatives

Their task is to stabilize the membranes of neurons (by blocking sodium channels). They also inhibit the propagation of pulses by releasing relays having such properties. Dibenzoazepine derivatives include:

  • oxycarbazepine
  • carbamazepine
  • lorazepam
  • klonazepam
  • diazepam

Benzodiazepine derivatives increase the effects of other hypnotics and react with muscle relaxants. What's more, they can make you feel tired and drowsy and can be addictive. Benzodiazepine derivatives cannot be combined with drugs and alcohol.

Sulfonamides are diuretics, their action is to inhibit the activity of the enzyme - carbonic anhydrase, which inhibits the production of hydrogen ions and inhibits the resorption of sodium ions in the renal tubules.

The loss of sodium ions is manifested by an increase in urine excretion, it also stabilizes cell membranes by removing excess ions from the body.

  • zonisamid
  • sultiam
  • urea derivatives

They block sodium channels, reducing the sodium permeability of the neuron's membrane. The most commonly used preparation is phenytoin, which is effective in partial and generalized seizures. It readily passes from the bloodstream to the brain. After intravenous administration, its concentration in the blood is visible even after a few minutes. Treatment with this agent should be monitored due to the possibility of overdose and the occurrence of neurotoxic symptoms.

  • imidy

These are drugs that, by blocking calcium channels in the neurons, prevent the release of catecholamines and the spread of impulses.

These drugs include:

  • ethylphenacemide
  • ethosuximide
  • benzodiazepine derivatives

Benzodiazepine derivatives have a sedative, anxiolytic, anticonvulsant and muscle-relaxing effect.

These types of drugs mimic the effects of endozepins, which are naturally compoundsfound in the central nervous system. Thanks to them, GABAergic transmission is facilitated.

They are considered drugs that effectively stop epileptic seizures. Thanks to them, facial contractions are milder and the time of convulsions is shortened. Benzodiazepine derivatives are used in people with myoclonic attacks. These types of drugs include, but are not limited to:

  • sulfonamides
  • drugs similar to GABA
  • gabapentin - binds to a protein receptor in the CNS, increases both the production and release of GABA, although it is not fully known how; as a result, GABAergic conductivity is enhanced and the bioelectric activity of neurons is inhibited; gabapentin is a GABA analog;
  • vigabatrin - blocks the breakdown of GABA, which increases its concentration; vigabatrin is a GABA-aminotransferase inhibitor;
  • other drugs for epilepsy
  • lamotrigine - its use is aimed at reducing the concentration of glutamate (excitatory neurotransmitter) by blocking the sodium channel;
  • levetiracetam
  • valproates - their use leads to the stimulation of GABA enzymes necessary for biosynthesis. The valproates include, among others. valproic acid, valpromide, magnesium valproate
  • selected barbiturates, e.g. phenobarbital, benzobarbital, methylphenobarbital

In small doses, barbiturates have a calming effect, putting the patient in a state of slight euphoria and relaxation. The use of high doses may aggravate this condition. The patient is then strongly aroused, has memory problems and impaired motor coordination.

Barbituric derivatives are very addictive, therefore the therapy with them should be as short as possible, and the doses administered should be as low as possible and only under the supervision of a physician. It is not always successful, which is why patients require higher and higher doses of drugs. Addiction makes it very difficult to stop taking the drug. Then the withdrawal syndrome appears, which manifests itself, among others, stomach pain, hallucinations and convulsions. Sudden discontinuation of this type of medication can lead to death.

These types of drugs cannot be combined with alcohol as it can lead to a collapse.

Barbiturates weaken the effect of contraceptives, hypoglycemic drugs and anticoagulants.

Barbiturate antiepileptic drugs interact with many drugs. They weaken the effect of anticoagulants, hypoglycemics and contraceptives. Barbiturates, in turn, increase the effect of non-steroidal anti-inflammatory drugs.

Medicines for epilepsynew generation

These are preparations that can be used in people who have failed other drugs. They are also given to pregnant women, but only after appropriate tests have been carried out. This is because they can increase the likelihood of fetal malformations.

The most common preparations belonging to this group are: lamotrigine and vigabatrin.

Antiepileptic drugs - side effects

Whether and what anti-epilepsy drugs will cause side effects depends on the individual patient and how their body responds to the drugs.

If anti-epileptic drugs have side effects, they are usually mild and occur when the patient starts treatment and when the dose is increased. The most common side effects are:

  • gastrointestinal complaints
  • memory and concentration disorders
  • mental slowdown
  • sedation
  • mood swings
  • dizziness

Dose-dependent side effects disappear after dose reduction.

Other side effects of epilepsy medications:

  • anemia
  • skin allergies
  • impotence
  • liver failure
  • kidney failure
  • dry mouth
  • weight gain

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