Pharmacology - Prep U - Chapter 23

A 15-year-old male client receiving phenytoin for treatment of epilepsy is being discharged from the hospital. What statement by Richard's mother leads you to believe she has understood your teaching related to his care and drug administration?

"I will make sure he has routine visits to the dentist." Gingival hyperplasia, the overgrowth of gum tissue, is common in patients who take phenytoin. It is especially common in children.

A 30-year-old female client is diagnosed with seizure disorder, and the provider is considering the use of carbamazepine. What assessment question best addresses the safety and effectiveness of the medication regimen?

"Is there any chance that you could be pregnant?" Carbamazepine is contraindicated during pregnancy. A female client of this age should be assessed for pregnancy prior to starting to take the drug. The client's history of hepatitis vaccinations does not have a major bearing on treatment. Visual changes are unlikely and there are not known optic conditions that contraindicate use. It is appropriate to assess the client's ability to pay but this does not directly relate to client safety.

A client has been diagnosed with partial seizures and has been prescribed carbamazepine. When providing health education about the safe and effective use of this medication, what should the nurse teach the client?

"It's safest if you avoid drinking alcohol while you're taking this drug." Use of alcohol during treatment with carbamazepine is contraindicated due to the potential for CNS depression. Carbamazepine is taken on an ongoing basis to prevent partial seizures; it is not a treatment for impending seizure activity. It is administered orally, not by injection, and it does not necessitate significant dietary changes.

A client who is receiving phenytoin has a serum drug level drawn. Which result would the nurse interpret as within the therapeutic range?

12 mcg/mL The therapeutic serum phenytoin levels range from 10 to 20 mcg/mL. Thus, a level of 12 mcg/mL would fall within this range.

A nurse who gives care on a neurological floor is working with several clients. Which client should the nurse prioritize for further assessment and possible interventions?

A client receiving pregabalin who is not responsive to verbal stimuli A client's decreased level of consciousness would be a priority for further assessment. It could be indicative of excessive CNS depression if the client is unable to be roused by voice. The client with a blood pressure of 106/69 may require further monitoring and possible interventions, but this blood pressure is not so low as to be considered an emergency. Addressing clients' learning needs and anxiety is also important, but less time dependent than a client who is not rousable.

A client has been admitted to the emergency department and is experiencing tonic-clonic seizures. What intervention should the nurse prioritize?

Administration of phenytoin IV as prescribed Active seizure activity is an emergency and the client's immediate physiological needs supersede the importance of therapeutic relationship. Phenytoin IV is among the most common treatments for tonic-clonic seizures; gabapentin PO is not typically used for this purpose, and PO administration of any type is unsafe due to the risk for aspiration. Treatment would not be withheld pending assessment of renal and hepatic function.

An 18-year-old client has been taking phenytoin for the past 6 months for epileptic seizures. The client's phenytoin levels routinely fall within the therapeutic range. The client contacts the health care provider reporting nausea, headache, and diarrhea. What would be the most appropriate intervention based on the assessment of the client's symptoms and laboratory results?

Advise the client to have his blood redrawn today to ensure that it is not at a toxic level. Clients may demonstrate adverse effects even if the serum level of phenytoin is "normal"; it is important to adjust the dose to the clinical response of the client, not the serum level.

A client is receiving carbamazepine therapy and the client's latest serum level of the drug is 13 mcg/mL. What action is most appropriate?

Anticipate a reduction is dosage A serum carbamazepine level of 13 mcg/mL is slightly over the therapeutic range of 4 to 12 mcg/mL, indicating need for a reduction in dosage. This not an emergency, though it needs to be addressed. This result does not threaten the client's renal function.

A client who has been taking valproic acid (sodium valproate) for a seizure disorder is asking the nurse about getting pregnant. Why is pregnancy discouraged in women who are being treated for seizure disorders?

Antiepilepsy drugs are teratogenic Antiepileptic drugs must be used cautiously during pregnancy because they are teratogenic in animals. Seizure disorders are not genetic. Seizure disorders are not familial. Antiepilepsy medications do not decrease fertility.

A nurse educating a client and their family about ethosuximide should tell them to notify the health care prescriber if which adverse reaction occurs? (Select all that apply.)

Blurred vision Joint pain Bruising A nurse educating a client and their family about ethosuximide should tell them to notify the physician if skin rash, joint pain, unexplained fever, sore throat, unusual bleeding or bruising, drowsiness, blurred vision, or pregnancy occurs.

A nurse is treating a patient who is receiving carbamazepine for a seizure disorder. The nurse knows that carbamazepine is contraindicated in patients with which diseases or disorders?

Bone marrow depression Carbamazepine is contraindicated in patients with previous bone marrow depression.

A patient with cortical focal seizures has been prescribed phenobarbital. What adverse reaction should the nurse monitor for in the patient?

CNS depression The nurse should monitor CNS depression in the patient undergoing phenobarbital treatment. Gingival hyperplasia is an adverse reaction in a patient administered ethotoins. Ataxia and urticaria are adverse reactions in patients undergoing anticonvulsant ethosuximide therapy.

A client in the clinic with a history of epilepsy has just tested positive for pregnancy. What is the nurse's next action?

Consult with the primary health care provider. The nurse should first consult with the primary health care provider. Research suggests an association between (a) the use of anticonvulsants by pregnant women with epilepsy and (b) an increased incidence of birth defects. The use of anticonvulsants is not discontinued in pregnant women with a history of major seizures because of the danger of precipitating status epilepticus. However, when seizure activity poses no serious threat to the pregnant woman, the primary health care provider may consider discontinuing use of the drug during pregnancy.

A client is prescribed lamotrigine for control of partial seizures. What is the most important medication teaching information the nurse should emphasize from the plan of care?

Contact the health care provider immediately if rash appears. GI upset, headache, rash, and dizziness are all adverse reactions of lamotrigine. The most important teaching point to emphasize is to notify the health care provider if a rash appears. A rash can develop into a Stevens-Johnson syndrome rash, a severe and potentially fatal rash.

Which type of seizures involves a loss of consciousness?

Generalized seizures Generalized seizures involve a loss of consciousness.

A client is receiving a hydantoin as treatment for tonic-clonic seizures. The nurse includes a discussion of what when teaching the client about this drug?

Gingival hyperplasia Hydantoins may cause gingival hyperplasia, severe liver toxicity, and bone marrow suppression. Physical dependence and withdrawal syndrome are associated with benzodiazepines.

An older adult client has been prescribed an antiseizure medication and is experiencing central nervous system depression. What is the nurse's most appropriate action?

Implement falls precautions CNS depression creates a risk for falls, especially in older clients. There is no need to assess vital signs on an hourly basis and the harm of bed rest exceeds the benefits. Occupational therapy has no direct relationship with treating CNS depression.

A nurse is caring for a patient prescribed phenobarbital for status epilepticus. What intervention should the nurse perform when the patient has been administered the drug?

Observe respirations frequently. When caring for a patient who has been administered phenobarbital, the nurse should observe respirations frequently. The nurse need not monitor blood glucose levels or body temperature. The nurse need not record fluid input and output. The nurse may need to observe blood glucose levels if the patient is being administered antidiabetic medications along with an anticonvulsant.

A client is to receive ethotoin. The nurse would expect to administer this drug by which route?

Oral Ethotoin is administered orally.

After teaching a group of nursing students about seizures, the instructor determines that the teaching was successful when the group identifies seizures that do not impair consciousness but can involve the senses or motor ability as which type?

Partial seizures Seizures that do not impair consciousness but can involve the senses or motor ability are classified as partial seizures. Generalized seizures involve loss of consciousness during the seizure. Tonic-clonic seizures are a type of generalized seizure involving alternate contraction and relaxation of the muscles, loss of consciousness, and abnormal behavior. Myoclonic seizures involve sudden, forceful contractions of single or multiple groups of muscles.

A nurse is caring for a patient administered ethotoin. What are signs of toxicity for which the nurse should monitor the patient?

Slurred speech The nurse should monitor the patient for slurred speech which is a sign of toxicity. Constipation, diarrhea, and urinary frequency are not signs of toxicity of ethotoin. Constipation and diarrhea are adverse reactions of barbiturates. Urinary frequency is an adverse reaction of succinimides.

A patient is prescribed daily doses of phenytoin for seizures. The nurse knows that a single dose should not be missed during the course of treatment. Which condition could result if a dose is missed?

Status epilepticus Status epilepticus may result from abrupt discontinuation of the drug, even when the anticonvulsant is being administered in small daily doses. Abrupt discontinuation of the drug does not cause CNS depression, hypotension, or nystagmus. CNS depression, hypotension, and nystagmus are adverse reactions of phenytoin.

A nurse is to administer an anticonvulsant drug. The nurse understands that this drug is classified as an oxazolidinedione. Which drug would the nurse most likely be preparing to administer?

Trimethadione Trimethadione is classified as an oxazolidinedione. Diazepam is classified as a benzodiazepine. Gabapentin is classified as a miscellaneous anticonvulsant. Levetiracetam is classified as a miscellaneous anticonvulsant.

In a person being treated for a diagnosed seizure disorder, what is the most common cause of status epilepticus?

abruptly stopping the antiseizure medications In a person taking medications for a diagnosed seizure disorder, the most common cause of status epilepticus is abruptly stopping AEDs. In other clients, regardless of whether they have a diagnosed seizure disorder, causes of status epilepticus include brain trauma or tumors, systemic or central nervous system (CNS) infections, alcohol withdrawal, and overdoses of drugs (e.g., cocaine, theophylline).

A client reports sensing an unusual smell just prior to experiencing a tonic-clonic seizure. What term is used to describe this event?

aura Tonic-clonic seizures are sometimes preceded by an aura—a brief warning, such as a flash of light or a specific sound or smell. None of the other options accurately describe this event.

After administering gabapentin, the nurse should assess the client for what possible adverse effect?

central nervous system (CNS) depression The most common adverse effects of gabapentin are associated with CNS depression and include dizziness, somnolence, insomnia, and ataxia. The drug has not been noted to cause tetany, hypersensitivity reactions, or paradoxical seizures.

What is a common risk for epileptic seizures during late infancy to early childhood?

fever Epilepsy can be classified as idiopathic or attributable to a secondary cause. Secondary causes in infancy include developmental defects, metabolic disease, or birth injury. Fever is a common cause during late infancy and early childhood, and inherited forms usually begin in childhood or adolescence.

A nurse is caring for a client with trigeminal neuralgia at a health care facility. The health care provider has prescribed carbamazepine. In which case is the use of carbamazepine contraindicated in clients with:

renal impairment. The nurse should know that carbamazepine is contraindicated among clients with renal impairment. Carbamazepine is not contraindicated in those with nervous breakdown, hearing impairment, and respiratory depression.

The nurse is caring for a 26-year-old client with partial seizures and has been prescribed oxcarbazepine as monotherapy. It will be critical for the nurse to inform the client of which needed action?

since she is taking oral contraceptives, she will need to use an additional form of birth control. Oxcarbazepine causes the circulating levels of oral contraceptives to decrease by up to half. The nurse should teach the client that she will need to use an additional form of birth control. Fatigue may be a concern, and the client should allow for rest periods during the day. Diplopia and abnormal vision can be adverse effects of the drug and eye exams should be part of the client's treatment regimen but they are not needed every other month. Informing the client that GI problems are common adverse effects is important but not as critical as preventing an unplanned pregnancy.

Because of the black box warning for clients taking lamotrigine, the nurse should instruct a client to discontinue this medication immediately if he or she develops what unexpected reaction?

skin rashes Adverse effects of lamotrigine include dizziness, drowsiness, headache, ataxia, blurred or double vision, nausea and vomiting, and weakness. The FDA has issued a black box warning related to the potential development of serious dermatological reactions.

A female client's seizure disorder has been successfully controlled by AEDs for years. She and her husband decide that it is time to start a family. She asks the nurse if it is safe for the fetus for her to continue her AEDs as prescribed. What is the nurse's best response?

"They are considered teratogenic." Sexually active adolescent girls and women of childbearing potential who require an AED must be evaluated and monitored very closely, because all of the AEDs are considered teratogenic. In general, infants exposed to one AED have a significantly higher risk of birth defects than those who are not exposed, and infants exposed to two or more AEDs have a significantly higher risk than those exposed to one AED.

During an in-service, the charge nurse explains to the licensed vocational nurse (LVN) that there are six categories of anticonvulsants with different mechanisms of action. The LVN demonstrates understanding of the action of the miscellaneous drug, gabapentin, by stating which of the following?

"This drug is a gamma-aminobutyric acid (GABA) agonist." Gabapentin is a miscellaneous drug acting as a GABA agonist. Hydantoins stabilize the hyperexcitability postsynaptically in the motor cortex of the brain. Succinimides depress the motor cortex, thus raising the seizure threshold. Benzodiazepines elevate the seizure threshold by decreasing postsynaptic excitation.

The nurse is monitoring the serum carbamazepine level of a client. Which result would lead the nurse to notify the prescriber that the client most likely needs an increased dosage?

2 mcg/mL Therapeutic serum carbamazepine levels range from 4 to 12 mcg/mL. Therefore, a level under 4 mcg/mL would suggest that the drug has not reached therapeutic levels, so the dosage may need to be increased.

The nurse has just begun administering phenobarbital intravenously to a child within status epilepticus. The nurse would expect this drug to begin working within which time frame?

5 minutes IV phenobarbital has an onset of action of approximately 5 minutes.

A nurse is caring for a patient who is going to take ethosuximide. During the nurse's initial assessment, the nurse learns that the patient's history includes hepatitis. Which laboratory test should be done before therapy is started?

Alanine aminotransferase (ALT) Because an adverse effect of ethosuximide can be liver function impairment, a baseline liver function study that includes the ALT should be done prior to starting ethosuximide. Baseline values will help the nurse determine if the drug is causing the abnormal values, and liver function studies will need to continue throughout the therapy. Blood glucose level would determine the glucose level in the blood. BUN would help determine urinary function. PTT is a test to assess the intrinsic system, which is the common pathway of clot formation in the blood. While these tests are important, they do not have a direct relationship to ethosuximide use.

What explanation should the nurse provide for why pregnancy is discouraged in women who are being treated for seizure disorders?

Antiepilepsy drugs are teratogenic. Antiepileptic drugs such as valproic acid must be used cautiously during pregnancy because they are teratogenic. Seizure disorders are not normally genetic or familial. Antiepilepsy medications do not decrease fertility.

The nurse is caring for a 15-year-old male who was involved in a motor vehicle accident and, as a result, sustained a closed head injury. The health care provider ordered phenytoin prophylactically to prevent seizures. The nurse understands that phenytoin works by what mechanism?

Decreases the sodium influx into the cell, thereby preventing the cell from producing a stimulus Phenytoin (Dilantin) is the prototype drug that controls seizures by decreasing sodium influx into the cells. Sodium influx produces an action potential, which then causes the neurons to fire.

When describing the action of barbiturates and barbiturate-like agents in the control of seizures, what would the nurse include?

Depression of motor nerve output The barbiturates and barbiturate-like drugs depress motor nerve output, inhibit impulse conduction in the ascending reticular activating system (RAS), depress the cerebral cortex, and alter cerebellar function. They stabilize nerve membranes throughout the CNS directly by influencing ionic channels in the cell membrane, thereby decreasing excitability and hyperexcitability to stimulation.

Which factor should the clinician reassess when combination therapy is ineffective?

Drug-drug interactions If combination therapy is ineffective, the clinician may need to reassess the patient for type of seizure, medical conditions or drug-drug interactions that aggravate the seizure disorder or decrease the effectiveness of antiseizure drugs, and compliance with the prescribed drug therapy regimen.

After teaching a class on drug classes used to treat seizures, the instructor determines that the teaching has been successful when the students identify which drug as most commonly used in the treatment of absence seizures?

Ethosuximide Ethosuximide is most frequently used to treat absence seizures. Mephobarbital, ethotoin, and primidone are typically used for tonic-clonic seizures.

A child suffers from absence seizures. What is the drug of choice for absence seizures?

Ethosuximide Ethosuximide is the drug of choice for absence seizures. Phenytoin is not recommended for absence seizures. Carbamazepine is not the drug of choice for absence seizures. Fosphenytoin is not recommended for absence seizures.

The nurse is caring for an 84-year-old client who is taking an AED and recognizes that this client is at increased risk for which condition?

Falls In older adults, decreased elimination by the liver and kidneys may lead to drug accumulation, with subsequent risks of dizziness, impaired coordination, and injuries due to falls.

When reviewing a journal article about seizure disorders, the nurse would expect to find tonic-clonic seizures and myoclonic seizures being classified as which type of seizures?

Generalized seizures Tonic-clonic seizures and myoclonic seizures are classified as generalized seizures. Partial seizures can be simple or complex. Complex seizures are partial seizures that involve impaired consciousness and variable unconscious repetitive actions, staring gaze, and hallucinations/delusions. Atonic seizures are a type of generalized seizure involving the loss of muscle tone where the person suddenly drops.

The nurse is formulating a care plan for a client with a seizure disorder. Which intervention would be an appropriate for the nurse to include?

Informing the client and family that seizure control is not gained immediately The nurse should inform the client and family that seizure control is not gained immediately when drug therapy is started. The goal is to avoid unrealistic expectations and excessive frustration while drugs and dosages are being changed in an effort to determine the best regimen for the client.

What best reflects the action of barbiturates when used to control seizures?

Inhibition of impulse conduction Barbiturates inhibit impulse conduction in the ascending reticular activating system. Barbiturates depress the cerebral cortex, depress cerebellar functioning, and depress motor nerve output.

What should the nurse include as a possible adverse effect when teaching a client about phenytoin?

Liver toxicity Liver toxicity is a potential adverse effect of phenytoin. Constipation, not diarrhea, is an adverse effect of phenytoin. Bone marrow suppression and leukopenia would be adverse effects of phenytoin. Physical dependence is an adverse effect associated with the use of benzodiazepines and barbiturates.

A client comes to the emergency department experiencing status epilepticus. Which medication would the nurse expect to administer?

Lorazepam Lorazepam is the drug of choice in the treatment of status epilepticus, an emergency characterized by continual seizure activity with no interruptions. Levetiracetam in an anticonvulsant is used as adjunctive therapy to treat partial onset seizures as well as tonic-clonic seizures. Trimethadione is used to treat epilepsy. Methsuximide is used for focal seizures.

A client is prescribed methsuximide. The nurse should expect to administer this drug by which route?

Oral Methsuximide is administered orally. Diazepam can be administered rectally. Diazepam or phenobarbital may be administered intramuscularly. Diazepam, fosphenytoin, phenytoin, valproic acid, and phenobarbital can be administered intravenously.

Simple seizures, motor seizures, and somatosensory seizures are classified as what type of seizure?

Partial seizures Simple seizures, motor seizures, and somatosensory seizures are classified as partial seizures.

A nurse is preparing to administer an anticonvulsant that produces its effects by stabilizing the hyperexcitability postsynaptically in the motor cortex of the brain. Which medication would the nurse be most likely to administer?

Phenytoin Hydantoins like phenytoin elicit their effects by stabilizing the hyperexcitability postsynaptically in the motor cortex of the brain. Valproic acid increases the levels of GABA to help stabilize the membranes. Ethosuximide depresses the motor cortex, creating a higher threshold before the nerves react to the convulsive stimulus. Lorazepam elevates the seizure threshold by decreasing postsynaptic excitation.

A 15-year-old is observed having a tonic-clonic seizure at school. Which behavior would allow the school nurse to recognize the clonic phase of the seizure?

Rapid rhythmic and symmetric jerking movements The tonic phase of a tonic-clonic seizure involves sustained contraction of skeletal muscles, abnormal postures, and absence of respiration. The clonic phase of the seizure is characterized by rapid rhythmic and symmetric jerking movements of the body.

The nurse has taught a client who is receiving lamotrigine about possible adverse effects. The nurse determines that the client has understood the teaching when the client identifies a need to promptly report what adverse effect?

Rash Lamotrigine has been associated with very serious to life-threatening rashes and the drug should be discontinued at the first sign of any rash. Anorexia is a common adverse GI effect. Fatigue is a common adverse CNS effect. Upper respiratory infection is an adverse effect of the drug, but it is not life threatening and does not need to be reported immediately.

A client is receiving lamotrigine as treatment for partial seizures. Which assessment finding would lead the nurse to stop the drug immediately?

Rash Lamotrigine has been associated with very serious to life-threatening rashes, and the drug should be discontinued at the first sign of any rash. Somnolence and confusion are typical CNS effects; anorexia is a common gastrointestinal effect.

While taking the vital signs of a hospitalized client admitted for seizure control due to epilepsy, the nurse notices a bloody toothbrush on the client's bedside table and scattered bruising over the client's extremities. What is the nurse's best action?

Report the findings to the primary health care provider immediately. The client has a history of epilepsy and is likely taking anticonvulsants. Hematologic changes when taking anticonvulsants needs to be reported immediately to the health care provider. Such changes include bleeding gums and easy bruising. Abuse is not the likely cause of the client's bruising given the history of epilepsy. Telling the client to ask for assistance when ambulating and offering a soft toothbrush are appropriate, but the health care provider needs to be notified immediately about the hematologic changes.

A 77-year-old client is being admitted to a long-term care facility. The client has a history of absence seizures has been treated with ethosuximide for many years. While the nurse is creating a plan of care on the client, the nurse understands the potential adverse effects of this drug and would consequently prioritize which nursing diagnoses?

Risk for Falls Common adverse effects of ethosuximide are drowsiness, dizziness, and lethargy- which potentiates the risk for fall in this client. Respiration, urinary function, and skin integrity are not normally affected by the use of ethosuximide.

Which nursing diagnosis would be most important for a nurse to include in the plan of care for a client who is receiving an antiseizure agent and experiencing common adverse effects?

Risk for injury CNS depression that accompanies many antiseizure agents could lead to injury. Therefore risk for injury and safety measures would be the priorities. Imbalanced fluid volume would be appropriate if the client was experiencing vomiting or diarrhea or showing signs of dehydration. Impaired skin integrity might be appropriate if the client developed a rash. Ineffective coping would be appropriate if the client was verbalizing difficulties with his condition or therapy.

The nurse is participating in the care of a client in status epilepticus who is receiving phenobarbital IV. Which nursing diagnosis should the nurse prioritize during this client's current care?

Risk for injury related to seizure activity Seizures present an acute risk for injury which the nurse must prioritize when caring for the client. Cognitive and/or sensory disruptions are likely as well, but none of these presents such a high risk to the client's safety as the risk for injury.

A patient with partial seizures has been prescribed succinimides at a health care facility. The patient experiences GI upset after succinimides administration. What should the nurse instruct the patient to do?

Take the drug with food or milk. If the patient experiences GI upset after succinimides administration, the nurse should instruct the patient to take the drug with food or milk. The nurse need not instruct the patient to take the drug once only at bedtime, before meals, nor avoid taking fruit juice.

A client is prescribed topiramate. The nurse cautions the client to avoid the intake of alcohol for which reason?

The client is at risk for increased CNS depression. Combining alcohol with topiramate increases the client's risk for CNS depression. Topiramate combined with alcohol does not result in a disulfiram-like reaction. Drug dependency is not associated with the use of topiramate and alcohol. The combination of topiramate and alcohol is not associated with the development of a hypertensive crisis.

After teaching a group of students about anticonvulsant therapy, the instructor determines that the teaching was successful when the group identifies which drug as eliciting its effects by increasing levels of gamma-aminobutyric acid (GABA), which stabilizes cell membranes?

Valproic acid Carboxylic acid derivatives like valproic acid elicit their effects by increasing levels of gamma-aminobutyric acid (GABA), which stabilizes cell membranes. Gabapentin is a GABA agonist. Topiramate blocks seizure activity rather than raising the threshold. Trimethadione decreases the repetitive synaptic transmissions of nerve impulses.