McKenna's Pharmacology for Nursing, 2e

369

C H A P T E R 2 3 Antiseizure agents

KEY POINTS

Implementation with rationale

■■ Drugs used in the treatment of partial seizures include drugs that stabilise the nerve membrane by altering electrolyte movement or increasing GABA activity. ■■ Some of the drugs used to treat generalised seizures have also been found to be useful in treating partial seizures. ■■ Adverse effects associated with the use of drugs used in treating partial seizures include CNS depressive effects and dermatological disorders. CHAPTER SUMMARY ■■ Epilepsy is a collection of different syndromes, all of which have the same characteristic: a sudden discharge of excessive electrical energy from nerve cells located within the brain. This event is called a seizure. ■■ Seizures can be divided into two groups: generalised and partial (focal). ■■ Generalised seizures can be further classified as: tonic–clonic (grand mal); absence (petit mal); myoclonic; febrile; and rapidly recurrent (status epilepticus). ■■ Partial (focal) seizures can be further classified as simple or complex. ■■ Drug treatment depends on the type of seizure that the person has experienced and the toxicity associated with the available agents. ■■ Drug treatment is directed at stabilising the overexcited nerve membranes and/or increasing the effectiveness of GABA, an inhibitory neurotransmitter. ■■ Adverse effects associated with antiepileptics (e.g. insomnia, fatigue, confusion, GI depression, bradycardia) reflect the CNS depression caused by the drugs. ■■ People being treated with an antiepileptics should be advised to wear or carry a MedicAlert notification to alert emergency medical professionals to their epilepsy and their use of antiepileptics drugs. ■■ People being treated with antiepileptic are often on long-term therapy, which requires compliance with their drug regimen and restrictions associated with their disorder and the drug effects.

■ ■ Administer the drug with food to alleviate GI irritation if GI upset is a problem. ■ ■ Monitor FBC before and periodically during therapy to detect and prevent serious bone marrow suppression. ■ ■ Protect the person from exposure to infection if bone marrow suppression occurs. ■ ■ Discontinue the drug if skin rash, bone marrow suppression, unusual depression or personality changes occur to prevent further serious adverse effects. ■ ■ Discontinue the drug slowly, and never withdraw the drug quickly, because rapid withdrawal may precipitate seizures. ■ ■ Arrange for counselling for women of childbearing age who are taking these drugs. Because these drugs have the potential to cause serious damage to the fetus , women should understand the risk of birth defects and use barrier contraceptives to avoid pregnancy. ■ ■ Evaluate for therapeutic blood levels of carbamazepine (4 to 12 mcg/mL) to ensure that the most effective dose is being used. ■ ■ Provide safety measures to protect the person from injury or falls if CNS changes occur. ■ ■ Provide teaching, including drug name and prescribed dosage, as well as measures for avoidance of adverse effects, warning signs that may indicate possible problems and the need for periodic laboratory testing and monitoring and evaluation to enhance knowledge about drug therapy and to promote compliance. MedicAlert bracelet to alert emergency workers and healthcare providers about the use of an antiepileptic drug. ■ ■ Offer support and encouragement to help the person cope with the drug regimen. Evaluation ■ ■ Monitor response to the drug (decrease in incidence or absence of seizures). ■ ■ Monitor for adverse effects (CNS changes, GI depression, bone marrow suppression, severe dermatological reactions, liver toxicity, renal stones). ■ ■ Evaluate the effectiveness of the teaching plan (person can give the drug name and dosage and name possible adverse effects to watch for and specific measures to prevent them; person is aware of the risk of birth defects and the need to carry information about the diagnosis and use of this drug). ■ ■ Suggest that the person wear or carry a

Knowing your strengths and weaknesses helps you to study more effectively. Take a PrepU Practice Quiz to find out how you measure up!