62. Epilepsy/Seizures Flashcards
What are possible complications with long-term phenytoin therapy? (Select ALL that apply.)
A. Hirsutism
B. Renal dysfunction
C. Gingival hyperplasia
D. Osteoporosis
E. Hypertension
A, C, D. Long-term complications of phenytoin therapy can include connective tissue complications (coarsening of facial features, lip enlargement and gingival hyperplasia-good dental hygiene should be stressed), systemic lupus erythematosus (SLE), toxic hepatitis, liver damage, macrocytic anemia (due to folic acid deficiency, which should be supplemented), and osteoporosis and osteomalacia due largely to vitamin D and calcium deficiencies (which should be supplemented).
Which of the following side effects/adverse drug reactions are possible with the use of zonisamide? (Select ALL that apply.)
A. Pancreatitis
B. Contraindicated in sulfa allergy
C. Weight loss
D. Decreased sweating
E. Kidney stones
B, C, D, E. Zonisamide is a sulfonamide and is contraindicated in sulfonamide allergy.
Similar to topiramate except no sulfa allergy for topiramate.
A hospital pharmacist is preparing a phenytoin injection. The pharmacist should use the following diluent:
A. Lactated ringers
B. Sterile water
C. D5W
D. D20W
E. NS
E. Phenytoin should be diluted in NS only. It is administered in a large vein (extravasation can cause tissue necrosis), with an inline 0.22 micron filter.
A patient has been admitted in the hospital with symptoms of acute phenytoin toxicity. Initial lab reports include a phenytoin level of 12.6 mcg/mL and an albumin level of 1.5 g/dL. Which of the following statements is accurate?
A. The albumin level is expected to be higher than reported.
B. The albumin level is expected to be lower than reported.
C. The phenytoin level is expected to be higher than reported.
D. The phenytoin level is expected to be lower than reported.
E. The phenytoin level is expected to be as reported.
C.
Claire is a thirteen year old girl who has begun using carbamazepine therapy. She and her parents should have received counseling on these possible side effects:
A. Nausea, drowsiness, dizziness
B. Increased sodium levels.
C. Increased serum vitamin D levels.
D. Giddiness or agitated behavior
E. Insomnia, or trouble sleeping
A. Nausea, drowsiness and dizziness are more likely initially as the patient is getting used to the drug, or when receiving dose increases. A rash may be mild and transitory, or may be serious and require drug discontinuation-carbamazepine can cause Stevens Johnson Syndrome and Toxic Epidermal Necrolysis. Vitamin D and folate levels should be supplemented, if dietary intake is low, especially among females of child-bearing age. Carbamazepine can cause syndrome of inappropriate antidiuretic hormone (SIADH). This would cause low serum sodium and cognitive dysfunction (such as confusion) and is more likely when the carbamazepine level is toxic.
Many anticonvulsants deplete folic acid levels. Low folic acid levels cause risk for severe neural tube birth defects. When dispensing an anticonvulsant to a female of child-bearing age, it is a good time to ensure that folic acid intake is adequate. Which of the following suggestions might help a patient who does not consume folate-fortified food products (most commercially-prepared bread and cereal products sold in the U.S. are folate-fortified, in order to reduce the incidence of serious birth defects):
A. Eat a lot of avocados.
B. Eat a banana each day.
C. Eat a lot of white rice.
D. Eat a lot of corn tortillas.
E. Use a folic acid supplement that contains a high amount of folic acid (such as 800 mcg).
E. They may also receive a prescription dose of 1 mg from the prescriber. Some breakfast cereals are fortified with up to 400 mcg per serving. Avocados are rich in potassium. Bananas contain 20 mcg of folic acid-not a lot, but they are healthy for a variety of reasons.
A patient gave the pharmacist a prescription for Neurontin 300 mg TID #90. Which of the following is an appropriate generic substitution for Neurontin?
A. Gabapentin
B. Levetiracetam
C. Phenytoin
D. Lamotrigine
E. Topiramate
A. The generic name of Neurontin is gabapentin.
Choose the correct statement concerning Lamictal:
A. Reduced sweating can occur.
B. Photosensitivity from this drug requires avoidance of the sun in children.
C. It is Pregnancy Category X.
D. A slow dose titration is required, due primarily due to the risk of rash.
E. The brand name is Keppra.
D. Most of the anticonvulsants cause CNS side effects, such as ataxia, impaired concentration and dizziness. Most, including lamotrigine are also sedating; this is commonly called somnolence, or sleepiness.
A patient had several seizures when she was a young child. She is now 13 years old and has been seizure free for at least 5 years. Choose the correct statement:
A. She should continue anticonvulsant therapy until she is at least fifteen years old.
B. The drug should be discontinued immediately (stopped today) since she has been seizure-free for at least 2 years.
C. The drug can be discontinued immediately (stopped today) since she has been seizure-free for at least 3 years.
D. The drug can be discontinued immediately (stopped today) since she has been seizure-free for at least 4 years.
E. The drug should be tapered gradually to minimize the risk of seizures.
E. With all anticonvulsants, the drug should be tapered gradually (over 2 or more months) to minimize the risk of seizures. It may be possible to discontinue anticonvulsants after a seizure-free period of two to four years. In patients who had one seizure (such as someone who had an acute head injury) it may be possible to discontinue the drug if they are seizure-free for six to twelve months.
Which of the following side effects/adverse drug reactions can occur with Lamictal? (Select ALL that apply.)
A. Diplopia, blurred vision
B. Ataxia, headache
C. Sleepiness, dizziness, difficulty thinking and concentrating
D. Rash, which could become serious, and potentially, fatal
E. Interactions with many other drugs are likely.
A, B, C, D, E. Any side effects like this: Sleepiness, dizziness, difficulty thinking and concentrating…are likely if the drug is an anticonvulsant, although, depending on the agent, the degree will vary. Some of them are much worse than others; for example, with phenobarbital, the patient’s mind is “numbed.” A major concern with the use of anticonvulsants in children is the effect on cognitive function.
A young boy was given phenobarbital. He did not seem to be keeping up with his classmates in school. His teacher asked the father if his son “had always been a little slow.” Choose the correct statements: (Select ALL that apply.)
A. Phenobarbital can cause impaired memory and concentration, typically more so than most other anticonvulsants.
B. The parents should request a consult with a neurologist to see if the child can be switched to another drug.
C. If phenobarbital is stopped it will require a slow taper and another anticonvulsant should be brought on board concurrently.
D. In some children, phenobarbital can cause hyperactivity.
E. Phenobarbital is not a controlled substance.
A, B, C, D. Phenobarbital is a barbiturate and is C IV. It causes physical dependence and will require a taper-off. Discontinuing the drug too rapidly (or any anticonvulsant) will increase the seizure risk. If it is stopped the specialist will be titrating up another drug. Phenobarbital can lower IQ. It is an enzyme inducer; watch for drug interactions.
Choose the correct statement concerning gabapentin therapy:
A. Gabapentin is approved for epilepsy.
B. Gabapentin is approved for diabetic neuropathy.
C. Gabapentin is renally cleared and dose-adjusted at a creatinine clearance less than 10 mL/min.
D. Gabapentin frequently causes significant weight loss.
E. Gabapentin is a strong CYP 3A4 inducer.
A. Gabapentin is approved for epilepsy, restless leg syndrome and postherpetic neuralgia. It is not approved for diabetic neuropathic pain, and does not provide much benefit for this use in most patients. It is renally cleared, but both gabapentin and pregabalin (Lyrica) are dose-adjusted when the creatinine clearance is less than 60 mL/minute, which is about half of normal renal function.
Choose the correct statements concerning oxcarbazepine therapy: (Select ALL that apply.)
A. Oxcarbazepine induces the metabolism of many drugs.
B. Serious skin reactions can occur with this agent.
C. The brand name is Tegretol.
D. Dizziness, diplopia, somnolence, fatigue and nausea are possible side effects.
E. If a patient experienced hypersensitivity to carbamazepine, they should be considered at-risk for hypersensitivity with oxcarbazepine.
A, B, D, E.
Which anticonvulsant requires genetic testing prior to use in persons of Asian descent?
A. Phenytoin
B. Zonisamide
C. Carbamazepine
D. Levetiracetam
E. Gabapentin
C. Carbamazepine has boxed warnings for serious skin reactions, including SJS and TEN: If of Asian ancestry the patient must be tested for the HLA-B 1502 allele prior to therapy; if positive, the drug cannot be used.
After Claire, a thirteen year-old girl, began to take carbamazepine, she tried to slit her wrists. Her parents were not warned to watch her for worsening mood or changes in behavior. Choose the correct statement:
A. The anticonvulsants do not carry a risk of mood changes; something else was occurring.
B. Carbamazepine makes people feel happy (slightly euphoric) and generally improves mood.
C. The anticonvulsants have a FDA warning for increased risk of suicidal ideation or behavior.
D. She should have the carbamazepine dose increased quickly to overcome this adverse effect.
E. The physician should add-on temazepam to help Claire relax when starting carbamazepine therapy.
C. Anticonvulsants have a warning concerning an increased risk of suicidal ideation or behavior; monitor for mood worsening and unusual behavior. Although the risk is low, there is an increase over placebo in mood changes among patients taking various anticonvulsants. If not warned, the caregiver or patient may not attribute the problem to the drug.
Side effects of divalproex sodium may include the following: (Select ALL that apply.)
A. GI upset, nausea
B. Tachypnea
C. Insomnia, akathisia
D. Weight gain
E. Hair loss, thinning
A, D, E.
A patient is taking birth control pills for contraception. She requires an anticonvulsant. Which agent would not lower the efficacy of her contraceptive method?
A. Phenobarbital
B. Carbamazepine
C. Oxcarbazepine
D. Phenytoin
E. Levetiracetam
E. All the agents listed except levetiracetam are enzyme inducers and should not be used with oral contraceptives (and many other medications). If she does require one of these anticonvulsants, she will risk pregnancy if she uses this method of birth control.
Choose the correct statement concerning carbamazepine therapy:
A. Carbamazepine formulations include tablets, capsules, and an injection.
B. The therapeutic range is 50-100 mcg/mL
C. The drug has a boxed warning for renal failure.
D. Carbamazepine is a potent inducer and will lower the concentration of many other drugs.
E. Carbamazepine has less drug interactions than oxcarbazepine.
D. Carbamazepine (Carbatrol, Epitol, Equetro, Tegretol, Tegretol-XR) is a potent inducer of many CYP 450 enzymes, including 3A4. Carbamazepine is available as tablets, capsules, and an oral suspension.
