McKenna's Pharmacology for Nursing, 2e

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C H A P T E R 2 3 Antiseizure agents

E pilepsy , the most prevalent of the neurological dis­ orders, is not a single disease but a collection of different syndromes characterised by the same feature: sudden discharge of excessive electrical energy from nerve cells located within the brain, which leads to a seizure . In some cases, this release stimulates motor nerves, resulting in convulsions, with tonic–clonic muscle con­ tractions that have the potential to cause injury, tics or spasms. Other discharges may stimulate autonomic or sensory nerves and cause very different effects, such as a barely perceptible, temporary lapse in consciousness or a sympathetic reaction. Because epilepsy involves a loss of control, it can be very frightening to people when they are first diagnosed (Box 23.1). The treatment of epilepsy varies widely, depend­ ing on the exact problem and its manifestations. The drugs that are used to manage epilepsy are called antiepileptics , or antiseizure agents, and are sometimes referred to as anticonvulsants; however, because not all types of epilepsy involve convulsions , this term is not generally applicable. The drug of choice for any given situation depends on the type of epilepsy, person’s age (Box 23.2), specific characteristics such as cultural vari­ ations (Box 23.3) and tolerance for associated adverse effects. Drugs can be used to treat more than one type of seizure. Table 23.1 lists drugs and the types of seizures that they can be used to treat. Teaching and counselling people with epilepsy Epilepsy, with its stigma, is frightening to people who know little about the disease.This condition has long been associated with some sort of brain dysfunction or possession by the devil or evil spirits. In some eras, exorcism was the first choice of treatment for a person with a seizure disorder. A person who receives a diagnosis of epilepsy must deal with this stigma as well as the significance of the diagnosis. What does having epilepsy mean? Individuals who are newly diagnosed with epilepsy must consider restrictions on their independence as well as the prospect of chronic therapy for control of this problem. In our society, the ability to be readily mobile—to drive to appointments, work or religious obligations—is very important to many people. In most cases, the driving privileges of affected individuals are revoked, at least temporarily.The conditions for recovering the licence vary with the diagnosis and the laws of each Australian state or territory and in New Zealand. The person who is newly diagnosed with epilepsy has to cope not only with the stigma of epilepsy, but also with the loss of a driver’s licence.The nurse may be in the best position to help the person adjust to both of these problems through education and referrals to community resources.Thorough teaching should include the following: Individual and family teaching BOX 23.1

NATURE OF SEIZURES The form that a particular seizure takes depends on the location of the cells that initiate the electrical dis­ charge and the neural pathways that are stimulated by the initial volley of electrical impulses. For the most part, epilepsy seems to be caused by abnormal neurons that are very sensitive to stimulation or over-respond for some reason. These neurons do not appear to be different from other neurons in any other way. Seizures caused by these abnormal cells are called primary seizures because no underlying cause can be identified. In some cases, however, outside factors—head injury, drug overdose, environmental exposure and so on—may precipitate seizures. Such seizures are often referred to as secondary seizures. Classification of seizures Accurate diagnosis of seizure type is very important for determining the correct medication to prevent future seizures while causing the fewest problems and adverse effects. Seizures were formerly categorised as grand mal (tonic–clonic seizures) or petit mal (absence seizures), but the International Classification of Seizures currently refers to seizures in a more systematic approach (based on the description of symptoms and characteristics), • Explanations of old stigmas. • Ways in which people may react to the diagnosis. • Ways in which people can educate family, friends and employers about the realities of the condition and its treatment. • Actions to take if a seizure happens so that no injuries occur and no panic develops. • Information about the availability of public transportation. • The importance of encouraging people with epilepsy to carry or wear a MedicAlert identification, to alert any emergency caregivers to their condition and to what drugs they are taking if they are not able to speak for themselves. • Contact information regarding other community support services. Many communities have epilepsy support groups that can supply information on valuable resources as well as updated facts about the laws in each area. While people are first adjusting to epilepsy and its implications, it may help to put them in contact with such organisations.The local chapter of Epilepsy Australia may be able to offer support groups, lists of resources and support. Individuals with epilepsy should have several options for getting around without feeling that they are being a burden or an imposition.