Pharmacology - Prep U - Chapter 23

Which type of seizures involves a loss of consciousness?

Generalized seizures Generalized seizures involve a loss of consciousness.

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.

The nurse has been educating the client on the self-administration of phenytoin. Which statement made by the client demonstrates an understanding of the medication?

"I'll make sure to take the drug with food." Phenytoin should be taken with food to reduce the chance of stomach upset. It should be taken on a regular basis and not only when a seizure occurs. The client should not arbitrarily reduce the dose of phenytoin. Abrupt cessation can cause seizures.

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.

One week ago, a client began taking ethosuximide 500 mg/day PO for the treatment of absence seizures. The client reports gastrointestinal (GI) upset after taking with the drug. What health education should the nurse provide?

"Try taking your pills at the same time as you eat some food." If GI irritation occurs with ethosuximide or other anticonvulsants, the client should be encouraged to take the medication with food to reduce this adverse effect. Taking the drug 1 to 2 hours after meals would not reduce this effect. The nurse must be cautious when recommending the use of OTC medications. GI effects are unlikely to necessitate a change in medications.

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.

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 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.

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 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 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.

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.

The nurse is reviewing the results of a hospital client's serum phenytoin level, which has just become available. The results indicate that the client's phenytoin level is 17.5 mcg/mL. What is the nurse's best action?

Document the fact that the nurse checked the client's phenytoin levels The therapeutic range is 10 to 20 mcg/mL. Consequently, there is no action needed beyond documentation.

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.

When combination therapy is ineffective, what needs to be reassessed?

Drug-drug interactions Many of the AEDs have drug-drug interactions. Therefore, it is important to monitor for drug-drug interactions to arrange to adjust dosages appropriately if any drug is added or withdrawn from the drug regimen. The age and gender of the patient would not need to be reassessed and neither would whether or not the patient is truly having seizures.

A client has been prescribed carbamazepine for the prevention of seizures. What action should the nurse perform?

Educate the client about the need to ake the pills as scheduled Carbamazepine is administered orally on an ongoing basis. It is not an emergency treatment for seizure activity.

The community health nurse also assists the health care provdier in the decision-making process for AED drug titration by performing which function?

Ensuring that the client makes the appointments for serum drug levels The community health nurse may assist the provider to titrate drug doses by ensuring that the client keeps appointments for serum drug level testing and follow-up care.

The nurse instructs the parent of a young school-age child with a seizure disorder who takes an AED to be alert for what signs and symptoms?

Excessive sedation and interference with learning and social development AEDs must be used cautiously to avoid excessive sedation and interference with learning and social development.

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.

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.

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.

Phenobarbital is ordered for a child with status epilepticus. The nurse would anticipate administering this drug by which route?

Intravenous Although phenobarbital is available in oral and parenteral forms, status epilepticus is an emergency situation that requires the drug to be given intravenously to achieve a rapid onset of action.

What is the therapeutic action of acetazolamide?

It controls fluid secretion in the central nervous system (CNS). The sulfonamide diuretic acetazolamide controls fluid secretion in the CNS; it is thought to inhibit CNS carbonic anhydrase to decrease neuronal excitability. It is not known to bring about any of the other suggested responses.

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

Oral Ethotoin is administered orally.

A patient has been diagnosed with a brain tumor, which has caused partial seizure activity. The patient is being treated with the newest antiepileptic medication. Which medication is administered as monotherapy to diminish or eliminate seizures?

Oxcarbazepine Oxcarbazepine is a newer drug that is structurally related to carbamazepine. It is approved for monotherapy and is used to treat partial seizures. Fosphenytoin is approved for status epilepticus. Gabapentin is used for partial seizures but is not the drug of choice for monotherapy. Levetiracetam is a newer drug approved for treatment of partial seizures in combination with other AEDs.

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.

The nurse is educating the client who has been started on Dilantin and its side effects. Which symptom would indicate a life-threatening condition and should be reported to the healthcare provider immediately?

Rash with itching Shortness of breath, alteration in taste, and altered bowel function are all side effects or adverse reactions that a client may experience when taking Dilantin. If the client has a rash with itching, this could indicate a life-threatening adverse reaction such as Stevens-Johnson syndrome.

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.

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.

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 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.

A client, newly diagnosed with a seizure disorder, asks the nurse why the client is receiving a specific drug. What would be the best answer by the nurse?

When prescribing an AED, the health care provider takes into account the type of seizure the client is having. Type of seizure is a major factor in drug selection. Age and gender are not factors that impact the choice of AED.

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).

While speaking with a client, the nurse notes that the client stares off, unblinking. The nurse notes that after several prompts, the client blinks rapidly and then resumes normal conversation. This behavior is consistent with what type of seizure?

absence A type of generalized seizure is the absence seizure, characterized by abrupt alterations in consciousness that last only a few seconds. Generalized seizures (tonic-clonic or major motor seizure) involve sustained contraction of skeletal muscles; abnormal postures, such as opisthotonos; and absence of respiration, during which the person becomes cyanotic. The clonic phase is characterized by rapid rhythmic and symmetric jerking movements of the body. Tonic-clonic seizures are sometimes preceded by an aura. Other types of generalized seizures include the myoclonic type (contraction of a muscle or group of muscles) and the akinetic type (absence of movement).

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 medication may be administered intravenously (IV) to assist in reducing status epilepticus seizure activity?

diazepam IV diazepam is an adjunctive skeletal muscle relaxant administered for the treatment of severe recurrent convulsive seizures and status epilepticus. Ethosuximide, meperidine, and insulin are not administered for status epilepticus.

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.

What is the most common drug of choice prescribed for the treatment of seizure activity in adults?

phenytoin The oldest and most widely used antiepileptic drug (AED), phenytoin is often the initial drug of choice, especially in adults. None of the remaining drugs are as widely prescribed.

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.

What type of seizure activity is characterized by generalized tonic-clonic convulsions lasting for several minutes during which the client does not regain consciousness?

status epilepticus Status epilepticus is a life-threatening emergency characterized by generalized tonic-clonic convulsions lasting for several minutes or occurring at close intervals during which the client does not regain consciousness. None of the other options present with this described experience.