Pharamacology Chapter 24
Which statement made by a female patient newly diagnosed with complex partial seizures and starting treatment with valproic acid indicates a need for further teaching by the nurse? A) "The medication should not make me feel sleepy." B) "I should take the medication on an empty stomach." C) "I'll need to discuss a reliable form of birth control with my gynecologist." D) "I'll call my physician immediately if I develop a yellow tint to my skin or my urine appears tea-colored."
COrrect: B Gastrointestinal side effects, such as nausea, vomiting, and indigestion, can occur when valproic acid is taken on an empty stomach; this statement indicates that further teaching is needed. Valproic acid has minimal sedative effects, is teratogenic, and can lead to hepatotoxicity. Female patients of child-bearing age must use effective methods of birth control to prevent pregnancy and must be taught the signs of liver failure (abdominal pain, malaise, jaundice), which must be reported immediately.
Which instruction would be inappropriate to include in the teaching plan for a patient being started on carbamazepine (Tegretol)? A) "Take the medication with a glass of grapefruit juice each morning." B) "Notify the physician if you are gaining weight or your legs are swollen." C) "Nausea, vomiting, and indigestion are common side effects of carbamazepine." D) "Have liver function tests performed on a routine basis."
Correct: A Grapefruit juice can inhibit the metabolism of carbamazepine, possibly leading to increased plasma drug levels; therefore, it should be avoided. Carbamazepine can inhibit renal excretion of water by promoting increased secretion of antidiuretic hormone. Weight gain and swollen extremities can be a sign of water retention and should be reported to the physician. Nausea, vomiting, and indigestion are common adverse effects of valproic acid, and the patient should be made aware of them. Liver function studies are monitored for patients taking valproic acid because of the risk of liver toxicity.
11. Which drug should be used with caution in a patient with first-degree atrioventricular (AV) heart block? A) Lacosamide (Vimpat) B) Felbamate (Felbatol) C) Tiagabine (Gabitril) D) Levetiracetam (Keppra)
Correct: A Lacosamide can prolong the PR interval and should be used with caution in patients with cardiac conduction problems and in those taking other drugs that prolong the PR interval, such as calcium channel and beta blockers. Felbamate, tiagabine, and levetiracetam do not affect the PR interval.
The nurse receives a laboratory report indicating that the phenytoin (Dilantin) level for the patient seen in the clinic yesterday is 16 mcg/mL. Which intervention is most appropriate? A) Continue as planned, because the level is within normal limits. B) Tell the patient to hold today's dose and return to the clinic. C) Consult the prescriber to recommend an increased dose. D) Have the patient call 911 and meet the patient in the emergency department.
Correct: A The therapeutic range for phenytoin is 10 to 20 mcg/mL. Because this level is within normal limits, the nurse would continue with the routine plan of care.
The nurse is caring for a patient receiving phenytoin (Dilantin) for treatment of tonic-clonic seizures. Which symptoms, if present, would indicate an adverse effect of this drug? (Select all that apply.) A) Swollen, tender gums B) Measles-like rash C) Productive cough D) Unusual hair growth E) Nausea and vomiting
Correct: A,B,D Adverse effects associated with phenytoin at therapeutic doses include mild sedation, gingival hyperplasia (swollen, tender gums), morbilliform (measles-like) rash, cardiovascular effects, and other effects, such as hirsutism (unusual hair growth) and interference with vitamin D metabolism.
The nurse is conducting discharge teaching related to a new prescription for phenytoin (Dilantin). Which statements are appropriate to include in the teaching for this patient and family? (Select all that apply.) A) "Be sure to call the clinic if you or your family notice increased anxiety or agitation." B) "You may have some mild sedation. Do not drive until you know how this drug will affect you." C) "This drug may cause easy bruising. If you notice this, call the clinic immediately." D) "It is very important to have good oral hygiene and to visit your dentist regularly." E) "You may continue to have wine with your evening meals, but only in moderation."
Correct: A,B,D Patients taking an antiepileptic drug are at increased risk for suicidal thoughts and behavior beginning early in their treatment. The U.S. Food and Drug Administration (FDA) advises that patients, families, and caregivers be informed of the signs that may precede suicidal behavior and be encouraged to report these immediately. Mild sedation can occur in patients taking phenytoin, even at therapeutic levels. Carbamazepine, not phenytoin, increases the risk for hematologic effects, such as easy bruising. Phenytoin causes gingival hyperplasia in about 20% of patients who take it; dental hygiene is important. Patients receiving phenytoin should avoid alcohol and other central nervous system depressants, because they have an additive depressant effect.
The nurse is preparing to give ethosuximide (Zarontin). The nurse understands that this drug is only indicated for which seizure type? A) Tonic-clonic B) Absence C) Simple partial D) Complex partial
Correct: B Absence seizures are the only indication for ethosuximide. The drug effectively eliminates absence seizures in approximately 60% of patients and effectively controls 80% to 90% of cases.
The nurse is teaching a patient newly diagnosed with epilepsy about her disease. Which statement made by the nurse best describes the goals of therapy with antiepilepsy medication? A) "With proper treatment, we can completely eliminate your seizures." B) "Our goal is to reduce your seizures to an extent that helps you live a normal life." C) "Epilepsy medication does not reduce seizures in most patients." D) "These drugs will help control your seizures until you have surgery."
Correct: B Epilepsy is treated successfully with medication in most patients. However, the dosages needed to completely eliminate seizures may cause intolerable side effects. Neurosurgery is indicated only for patients in whom medication therapy is unsuccessful.
The nurse is caring for a patient whose seizures are characterized by a 10- to 30-second loss of consciousness and mild, symmetric eye blinking. Which seizure type does this most closely illustrate? A) Tonic-clonic B) Absence C) Atonic D) Myoclonic
Correct: B This scenario accurately describes absence seizures. Tonic-clonic seizures present with convulsions and muscle rigidity followed by muscle jerks. Patients may experience urinary incontinence and loss of consciousness. Atonic seizures cause sudden loss of muscle tone. Myoclonic seizures present with sudden muscle contractions that last but a second.
The nurse suspects that a female patient is experiencing phenytoin toxicity if which manifestation is noted? (Select all that apply.) A) The patient complains of excessive facial hair growth. B) The patient is walking with a staggering gait. C) The patient's gums are swollen, tender, and bleed easily. D) The patient complains of double vision. E) The nurse observes rapid back-and-forth movement of the patient's eyes
Correct: B,D,E Manifestations of phenytoin toxicity can occur when plasma levels are higher than 20 mcg/mL. Nystagmus (back-and-forth movement of the eyes) is a common indicator of toxicity, as are ataxia (staggering gait), diplopia (double vision), sedation, and cognitive impairment. Hirsutism (excess hair growth in unusual places) and gingival hyperplasia (swollen, tender, bleeding gums) are adverse effects of phenytoin.
Which medication should the nurse anticipate administering to a patient in convulsive status epilepticus to halt seizure activity? A) Phenytoin (Dilantin) 200 mg IV over 4 minutes B) Phenobarbital 30 mg IM C) Lorazepam (Ativan) 0.1 mg/kg IV at a rate of 2 mg/min D) Valproic acid (Depacon) 250 mg in 100 mL of normal saline infused IV over 60 minutes
Correct: C Intravenous benzodiazepines, such as lorazepam or diazepam, are used for abrupt termination of convulsive seizure activity. Lorazepam is preferred over diazepam because of its longer effects. Once seizures have been stopped with a benzodiazepine, phenytoin may be administered for long-term suppression. Phenytoin and valproic acid are not benzodiazepines.
The nurse is assessing a patient receiving valproic acid (Depakene) for potential adverse effects associated with this drug. What is the most common problem with this drug? A) Increased risk of infection B) Reddened, swollen gums C) Nausea, vomiting, and indigestion D) Central nervous system depression
Correct: C Valproic acid is generally well tolerated. Gastrointestinal effects, which include nausea, vomiting, and indigestion, are the most common problems but tend to subside with use and can be lessened by taking the medication with food. Valproic acid does not cause hematologic effects resulting in an increased risk of infection, nor does it cause gingival hyperplasia. It causes minimal sedation.
A female patient who is originally from Thailand is seen in the clinic for seizure control. She receives a new prescription for carbamazepine (Tegretol). Before the patient takes the drug, which is the most appropriate initial nursing intervention? A) Warn her not to withdraw this drug abruptly. B) Recommend that she take this medication at bedtime with meals. C) Teach her family to assist with maintaining a seizure frequency chart. D) Ensure that genetic testing for HLA-B*1502 is performed.
Correct: D Although all these interventions are appropriate for this patient, the initial nursing intervention would be to ensure that genetic testing is performed. Carbamazepine is associated with several dermatologic effects, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Patients of Asian descent are at higher risk for serious dermatologic reactions with this drug because of a genetic variation known as HLA-B*1502. The FDA now recommends that before taking carbamazepine, patients of Asian descent undergo genetic testing.
Which medication can cause this acid-base disturbance: pH 7.32, paCO2 33, HCO3 20? A) Primidone (Mysoline) B) Lamotrigine (Lamictal) C) Lacosamide (Vimpat) D) Topiramate (Topamax)
Correct: D The arterial blood gas results reflect metabolic acidosis with partial respiratory compensation. Topiramate can cause metabolic acidosis, because it inhibits carbonic anhydrase; this increases renal excretion of bicarbonate, causing the plasma pH to fall. Hyperventilation is the most characteristic symptom. Primidone, lamotrigine, and lacosamide do not cause metabolic acidosis.