Chapter 18 study guide questions

1. A(n) ______ occurs when the muscles alternate between contracting and relaxing.

Convulsion

8. A chronic condition characterized by recurrent, unprovoked seizures is labeled _______.

Epilepsy

1. Uncontrolled electrical impulses and excessive neuronal firing are prevented by what?

GABA

9. _______ is the main inhibitory neurotransmitter in the mammalian central nervous system.

GABA

2. A(n) ______ is caused by disturbances of nerve cells in more diffuse areas and both hemispheres of the brain.

Generalized seizure

11. ______ is an excitatory neurotransmitter balanced by GABA.

Glutamate

4. A petit mal seizure is also known as a(n) __________ seizure.

Absence

6. A(n) _______ is subdivided into simple, complex, and secondarily generalized seizures.

Partial seizure

3. The ______ phase of a seizure is when abnormal movements cease.

Postictal

5. A(n) ______ is a paroxysmal involuntary alteration of behavior, movement, or sensation, triggered by an abnormal electric discharge in the brain.

Seizure

10. A patient who experience seizure after seizure is said to have ______.

Status epilepticus

7. A gran mal seizure is also called _______.

Tonic-clonic seizure

2. How do seizures occur?

When the activity from a focus spreads to other areas of the brain causing other neurons to join in the hyperactivity, seizures result.

10. Which of the following patient statements indicate a need for additional patient education regarding phenytoin? (Mark all that apply)

a. "I'll go to the pharmacy to buy a refill after I run out of my phenytoin." and b. "I will stop taking my phenytoin immediately if I become pregnant." - indicate that the patient needs more teaching. Patients should not allow themselves to run out of phenytoin or any antiepileptic drug as this may induce seizures if they miss daily doses. Although phenytoin causes a known fetal syndrome suddenly stop- ping phenytoin or any antiepileptic may induce seizures, which is dangerous for the fetus. The patient should work with their physician if they plan to become pregnant to see if they can be weaned off of the phenytoin before pregnancy or they should be managed during their pregnancy on drug therapy. Answers (c) and (d) indicate that the patient has the correct information. Phenytoin increases the risk of gingival hyperplasia and good oral hygiene is important to help minimize this risk. Phenytoin is highly protein bound and the patient needs to maintain an adequate intake of protein. However, once the dose of phenytoin is determined, the protein intake should not be greatly increased or the dose may need adjustment.

3. The therapeutic margin (index) for phenytoin (Dilantin) is

a. 10 to 20 mcg/mL -although this is the therapeutic index for phenytoin, it is important to remember that it is a guideline only.

6. Your patient is in status epilepticus, and the health care provider has ordered IV diazepam (Valium). How will you administer this drug?

a. 5mg/minute, undiluted -Diazepam should be administered undiluted, no faster than 5 mg per minute.

6. Which of the following patients would be a poor candidate for phenytoin (Dilantin) therapy?

a. A 60-year-old man with bradycardia -phenytoin affects ventricular automaticity, so it is contraindicated in patients with slow heart rhythms

9. Which of the following lab results indicate that the patient is at increased risk to experience toxicity from phenytoin?

a. Albumin level of 2.8 g/dl (Normal = 3.4-5.4 g/dL) -Phenytoin is highly protein bound. Low serum albumin, the most prevalent form of protein in the blood, makes the patients at risk for having more free and active drug, and thus more effects from the dose of phenytoin, leading to increased risk of toxicity. Potassium (K+) levels are not related to phenytoin toxic- ity. Phenytoin when given to a pregnant birth may produce neonatal hemorrhage immediately after birth due to vitamin K inhibition, but vitamin K is not the same thing as potassium whose chemis- try symbol is K. Renal function will not directly alter phenytoin as the drug is metabolized to an inactive form in the liver. Although phenytoin binds to inac- tive sodium channels to prevent sodium from entering the cell and initiating an action potential low serum sodium levels that do not alter the action of phenytoin.

6. You are caring for a 6-year-old child who is to begin a regimen of ethosuximide for absence seizures. What information should be included in teaching for the child and his parents?

a. Drowsiness may occur initially, but this should go away after the child has been on drug therapy for a while -CNS depressant effects are common adverse effects from ethosuximide and other AEDs. However, fever and other signs of infection may indicate that a blood dyscrasia is occurring. Fatal blood dyscrasia, although not common, has occurred. Doses should never be doubled because of the likelihood of inducing overdosage. There are no known drug- food interactions with ethosuximide; fried foods do not need to be avoided.

1. Your patient has been prescribed phenytoin (Dilantin) for a seizure disorder. Which of the following should be included in this patient's discharge instructions?

b. "Brush and floss your teeth at least twice a day." -phenytoin may cause gingival hyperplasia, so good oral care is important

3. What are the subdivisions of generalized seizures?

tonic-clonic (grand mal), atonic, myoclonic, febrile, status epilepticus, absence (petit mal)

7. Pharmacotherapeutics for carbamazepine (Tegretol) include

a. bipolar disorder -carbamazepine is used in treating several psychiatric disorders

9. Your patient, age 22, calls the clinic and states that she is having trouble swallowing her topiramate (Topamax) tablets. You would advise her to

a. continue to swallow the medication whole and make an appointment to discuss the problem with her provider -Tablets should never be broken or chewed because of a bitter taste if broken.

19. In the elderly, phenobarbital (Luminal) therapy may induce

a. excitement and confusion -Children and older adults are prone to these paradoxical effects of phenobarbital therapy.

9. Serious adverse effects to valproic acid (Depakene) therapy include

a. liver toxicity -liver toxicity appears to be more of a risk in children younger than 2 years who are receiving multiple AED therapy.

17. A benefit of gabapentin (Neurontin) therapy is

a. minimal drug-food interactions and b. extensive pharmacotherapeutic profile -Gabapentin should be administered at least every 12 hours. Patients with renal insufficiency require lower dosing.

2. Your patient has been stabilized with a regimen of phenytoin. He now requires rifampin therapy, a drug to treat tuberculosis (TB) and known to increase the metabolism of phenytoin. The nurse should expect to

a. monitor blood phenytoin levels for a drop compared with before rifampin therapy. -As metabolism of phenytoin is increased because of the introduction of rifampin, there is less active phenytoin available for the patient. If blood levels fall below therapeutic range or the patient shows increased seizure activity, contact the prescriber.

7. Your patient has begun a regimen of carba- mazepine for grand mal seizures that have not been controlled by several other AEDs. To minimize adverse effects, the nurse should teach the importance of

a. returning for lab appointments and follow-up -Because carbamazepine can cause fatal blood dyscrasias (aplastic anemia and agranulocytosis) it is very important that a complete blood count be obtained regularly. Carbamazepine does not alter urinary elimination, requiring additional fluid intake. Like all AEDs, carbamaze- pine may cause CNS depression, includ- ing drowsiness when therapy is first started. The patient should avoid driving and other potentially dangerous activi- ties for which alertness is needed until it is known how the carbamazepine affects the patient.

14. The therapeutic margin (index) for ethosuximide (Zarontin) is

b. 40 to 100 mcg/mL -answers (a), (c), and (d) do not meet the minimum serum concentration necessary to control seizures

8. A patient is brought into the emergency department experiencing generalized tonic clonic seizures. The seizure has lasted 10 minutes by the time the patient has arrived at the emergency department. Based on current treatment guidelines, which of the following would the nurse expect to administer first to this patient?

b. IV diazepam or lorazepam -this patient is exhibiting status epilepticus, a medical emergency. an intravenous dose of a benzodiazepine, either lorazepam or diazepam, is required as son as possible. oral doses are not appropriate as the patient is not conscious and requires immediate systemic effects to control the seizure. ethosuximide is not used in status epilepticus

2. Which of the following statements concerning phenytoin (Dilantin) is incorrect?

b. It is most effective AED for absence seizures -Phenytoin is used for generalized and other psychomotor seizures, status epileptics, severe preeclampsia, trigeminal neuralgia, and for specific types of arrhythmias.

10. Your patient was brought to the emergency department after having a seizure. The patient states, "I've taken my primidone (Mysoline) twice a day. I never miss." Which of the following STAT tests would be indicated for this patient?

b. Phenobarbital level -Primidone is converted to PEMA and phenobarbital. To assess long-term use of primidone, you should obtain a phenobarbital level.

5. You are to administer phenytoin IV to your patient who is having a seizure, to minimize the risk of serious adverse effects to this patient, you should

b. administer the drug slowly -Too rapid administration of IV phenytoin may produce cardiovascular collapse, hypotension, and life-threatening arrhythmias. Phenytoin carries a black box warning to this effect. Have resuscitation equipment nearby when administering phenytoin IV. Blood levels would be expected to be below the therapeutic range if the patient is experiencing sei- zures. Gingival hyperplasia is a long-term adverse effect of phenytoin. Oral hygiene is important with long-term use. Warning the patient that he may be drowsy from therapy is inappropriate while the patient continues to have seizures.

12. Serious adverse effects to felbamate (Felbatol) therapy include

b. aplastic anemia -the incidence of aplastic anemia is more that 100 times the incidence found in the general population

8. Serious adverse effects to carbamazepine (Tegretol) therapy include

b. blood dyscrasias -potentially fatal blood dyscrasias, such as aplastic anemia, thrombocytopenia, and agranulocytosis, can occur.

10. Serious adverse effects to topiramate (Topamax) therapy include

b. decreased sweating and hyperthermia -patients with decreased sweating and elevated temperature should seek medical attention

1. Phenytoin (Dilantin) inhibits seizure activity by

b. decreasing sodium influx from the neurons in the motor cortex of the brain. -Phenytoin reversibly binds to sodium channels while they are in the inactive state, which delays the return of the channel to an active state.

13. The drug of choice for the treatment of absence seizures is

b. ethosuximide (Zarontin) -ethosuximide controls the action potentials in the hypothalamic neurons responsible for absence seizures

2. Your patient who takes phenytoin (Dilantin) tells you that another physician has prescribed several new drugs. What is your best response?

c. "Before you start any new drugs, be sure both doctors known what the other doctor is prescribing." -you need more information before you tell the patient to take or not take the additional medication. it is best to refer back to the prescribers

4. Your patient has been prescribed ethosuximide (Zarontin) for absence seizures. The patient tells you of an episode of hepatitis in the past. Which of the following laboratory tests should be completed before the initiation of therapy?

c. AST, ALT -ethosuximide may cause liver problems, so it would be prudent to know if the patient's liver had been damaged by his bout of hepatitis

5. The most common adverse effects to phenytoin (Dilantin) occur in which body system?

c. CNS -CNS symptoms include nystagmus, ataxia, dysarthria, slurred speech, mental confusion, dizziness, insomnia, transient nervousness, numbness, tremor, and headahce

5. Your patient, who is taking ethosuximide, reports a sore throat and easy bruising. Which of the following diagnostic tests should you coordinate?

c. Complete blood count -ethosuximide may induce anemia, which would increase the risk of infections. the CBC will indicate the WBC count.

11. Serious adverse effects to levetiracetam (Keppra) therapy include

c. asthenia -in addition to weakness (asthenia), levetiracetam may cause somnolence.

3. Your patient is a 22-year-old woman who receives phenytoin for seizures. Her disease is well controlled, and she has not had a seizure for 5 years. During her routine follow-up visit, she tells you that she is getting married and would like to have children. She asks if she should stay on the phenytoin if she becomes pregnant. Your best response would be that

c. before she attempts to become pregnant, she should consult with her provider to see if she could be weaned from the phenytoin. -Before the patient attempts to become pregnant, she should consult with her provider about the possibility of being weaned from the drug because she has been seizure free for 5 years. Phenytoin is a pregnancy category D drug and causes teratogenic effects in the fetus. Fetal phenytoin syndrome is not related to dose toxicity and may occur with normal therapeutic drug levels, although most women receiving this drug deliver healthy infants. She should not abruptly stop taking phenytoin because this may bring about recurring seizures or status epilepti- cus. In addition, fetal injury may occur if she stops and thus induces seizures.

8. Your patient takes carbamazepine (Tegretol). She calls the clinic and reports a sore throat and easy bruising. You would advise her to

c. come in to the clinic to be seen today -These are potential signs of infection and, because carbamazepine can induce serious blood dyscrasias, it is important to be seen as soon as possible.

16. The drug of choice for status epilepticus is

c. diazepam (Valium) -Diazepam and Ativan are the benzodiazepines used for status epilepticus. Although clonazepam and clorazepate are also benzodiazepines, they are used as a maintenance drug for very specific types of seizures. Phenytoin is used for status epilepticus, but only after a benzodiazepine has already been administered.

18. One of the most serious potential adverse effects of phenobarbital (Luminal) therapy is

c. respiratory depression -Respiratory depression is most likely to occur when the drug is taken with other CNS depressant drugs, especially alcohol.

4. Your patient receives nutrition through continuous tube feeding (30 cc/hour). He also is to receive phenytoin suspension via gastrostomy tube every 8 hours. To maximize the therapeutic effects of phenytoin, you should

c. turn the tube feeding off for 1 hour before and 1 hour after administering phenytoin. -tube feedings interfere with the absorption of phenytoin. phenytoin should not be mixed with tube feedings. daily doses of phenytoin cannot be combined; overdosage may result

1. Your patient is receiving phenytoin for seizures. There are new orders for the patient to start a regimen of omeprazole, a proton pump inhibitor, for gastroesophageal reflex disease (GERD). You should

c. verify if drug interactions exist between the drugs. -Phenytoin interacts with a long list of drugs. Before initiating any new drug therapy, the nurse should assess if there is a potential drug interaction. Adminis- tering the drugs on opposite days is not an acceptable practice; it will decrease the effectiveness of both therapies considerably and may precipitate seizures. Antacids, although they may be helpful adjuncts to omeprazole therapy, should not be administered with phenytoin because of interference with absorption, so there is no need to seek an order for antacids.

3. Your patient who takes phenytoin states, "I'm ready to get pregnant." What is your best response?

d. "Before you stop your medication, let's get you an appointment with the doctor." -pregnancy is a complex discussion that should be done by the provider. it is important that the patient does not abruptly stop taking the medication in the meantime.

7. A patient, age 18, calls the clinic and tells the advice nurse, "My friends all make fun of me because I have to take clonazepam (Klonopin). I'm not coming for my appointment, and I'm just going to stop taking this medication." The best response would be:

d. "If you stop your medication abruptly you may have seizures again." -although the patient may need to speak with a psychiatrist, it is more important at this moment to ensure his safety by telling him the potential for seizures should he stop the medication abruptly

4. Which of the following adverse effects would necessitate cessation of phenytoin (Dilantin) therapy?

d. Blistered skin rash -this type of integumentary symptom could be the beginning of Stevens-Johnson syndrome or exfoliative or purpuric dermatitis, all of which are potentially life threatening

20. Which of the following adverse effects may occur with all antiepileptic drugs?

d. Teratogenic effects infections -although all of the answers may occur with some antiepileptic drugs (AEDs), only teratogenic effects may occur with all AEDs.

15. Serious adverse effects to ethosuximide (Zarontin) therapy include

d. blood dyscrasias -in addition to blood dyscrasias, ethosuximide may induce SLE