Antiepileptic drugs – also known as anticonvulsants – are medications used to treat epilepsy (seizures). Furthermore, they are used prophylactically as migraine therapeutics and also in pain management. The first antiepileptic drugs were tested as early as 1912.
What are antiepileptic drugs?
Antiepileptic drugs are used to treat epilepsy and prophylactically as a migraine treatment. Antiepileptic drugs are chemical-pharmaceutical drugs used primarily to treat epileptic disorders. Depending on the pharmacological group to which the antiepileptic belongs, the drug is also used for other disorders. Other areas of use include neuralgic pain, fibromyalgia, neuropathy, paresthesias. In the case of anticonvulsants – as the antiepileptic drugs are also called – a distinction is made between the classic products and the so-called new antiepileptic drugs. Not every drug in these drug groups is suitable for all types of seizures. Different antiepileptic drugs are prescribed depending on which brain regions are affected in an epileptic seizure and whether the seizure is focal or generalized (affecting the entire brain). Antiepileptic drugs are primarily used to decrease the conduction of stimuli as well as the neuronal excitability of the central nervous system.
Application, action, and use
Antiepileptic drugs are used primarily to treat epileptic seizures. Epilepsy is caused by an overfunction of electrical nerve activity in the brain. As a result of the overload of the nerve pathways, brain function is significantly reduced. With each epileptic seizure, the brain is permanently damaged. Because of this, epilepsy absolutely must be treated or constantly prophylactically treated with antiepileptic drugs. However, antiepileptic drugs are not only used for epilepsy. They are used as prophylaxis during operations on the brain, spinal cord and spinal column to prevent a seizure during the surgical procedure. Especially in recent years, antiepileptic drugs have also been discovered for pain management. Together with selected analgesics, neuralgic pain can be successfully treated. Other uses of antiepileptics include alcohol and drug withdrawal and anesthesia. Antiepileptic drugs act directly on the nervous system and nerve cells. They ensure that nerve conduction is inhibited and the excitability of nerve cells in the brain is reduced. Antiepileptic drugs have three mechanisms of action. They affect neurotransmitters (messenger substances of the nervous system). The most important seizure-inhibiting neurotransmitter is gamma-amino-butyric acid (GABA). Benzodiazepines and barbiturates are used to increase the effect and duration of action of the brain’s own neurotransmitter GABA. Antiepileptic drugs also have an effect on sodium and calcium, which increase nerve conduction. With the help of antiepileptic drugs, the uptake of these minerals is reduced, so that the conduction of impulses and the excitability of the nerve cells are reduced or blocked. Another mechanism of action of antiepileptic drugs is inhibition of various enzymes in the brain that increase conduction as well as excitability of nerve cells.
Herbal, natural, and pharmaceutical antiepileptic drugs.
Antiepileptic drugs belong to the group of heterogeneous drugs. Antiepileptic drugs are classified into barbiturates, benzodiazepines, suximides, carboxamides, and the new antiepileptic drugs. Barbiturates such as phenobarbital and primodone are used for long-term treatment of epilepsy. The dosage form is by means of tablets. Benzodiazepines such as diazepam, lorazepam, chlordiazepoxide, and triazolam are also used for the continuous treatment of epileptic seizures. The dosage forms are tablets, capsules, injectable and dropper solutions. However, barbiturates and benzodiazepines are not classic antiepileptic drugs. Their actual areas of use include the treatment of depression, psychosomatic complaints, pain conditions and anxiety disorders. However, these groups of drugs have also been shown to be successful in the treatment of epilepsy. Suximides such as phenytoin are hydantoin derivatives used for the long-term treatment of epilepsy. Phenytoin has a broad mechanism of action and is suitable for mild forms of epilepsy as well as for grand mal seizures and status epilepticus.Phenytoin is available as tablets and as injectable solutions for acute treatment. Carboxamides such as carbamazepine and oxcarbazepine are used both for the treatment of epilepsy and in pain therapy. The dosage forms are tablets, retard tablets and injection solutions. Agents of 1st choice for continuous therapy are carbamazepine, valproate, diazepam, lorazepam. In case of intolerance or interaction with other drugs, phenobarbital, ethosximide and phanytoin are usually used. The so-called new antiepileptic drugs gabapentin, lamotrigine, tiagabine, topiramate, and vigabatrin, are used as add-on therapeutic agents in combination with other antiepileptic drugs.
Risks and side effects
Many antiepileptic drugs have a sedating effect, especially the group of benzodiazepines and barbiturates. Because of this, special care should be taken, especially when driving or operating machinery. Antiepileptic drugs should not be taken during pregnancy as they have been shown to harm the embryo. Due to this, care should be taken to avoid pregnancy. Since antiepileptic drugs reduce the effect of hormonal contraceptives (pill, three-month injection, Implanon), it is essential to use additional contraceptive methods such as condoms to avoid pregnancy. Antiepileptic drugs have a particularly intense effect on the heart and its function. If heart disease, liver dysfunction as well as kidney disease are present, antiepileptic drugs must not be taken. Other side effects include weight gain or loss, skin rash, itching, gait unsteadiness, coordination disorders, insomnia, speech disorders, involuntary movements, gingivitis, nausea, vomiting, and connective tissue disorders. Since interactions with other medications are common, be sure to consult your doctor and pharmacist when taking other medications, including homeopathic medications. Taking antiepileptic drugs makes it necessary to have regular checks of blood levels.
Interactions with other medications
Antiepileptic drugs can speed up the breakdown of other medications. The following are affected: birth control pills, antidepressants, valproic acid, cyclosporine, neuroleptics. The following drugs inhibit the breakdown of antiepileptic drugs, so that an overdose or poisoning may occur: Antibiotics such as erythromycin and troleandromycin, loratadine, protease inhibitors (HIV treatment), viloxazine, verapamil, etc.
Antiepileptic drugs should not be taken together with grapefruit juice because its ingredients inhibit the breakdown of antiepileptic drugs. Herbal medicines such as St. John’s wort must also not be taken with antiepileptic drugs, as they also greatly impair the effect of the drug. Vitamins and minerals such as calcium and magnesium can decrease the effectiveness of antiepileptic drugs. The antiepileptic drug carbamazepine should not be taken with the antiepileptic drug phenytoin because they reduce each other’s effectiveness.