Anticonvulsant Therapy
Question:
A patient with complex partial seizures is prescribed phenytoin to control recurrent seizures,
but the patient reports being reluctant to take the drug long term because of its side effects.
Which information would the nurse provide this patient? “Tolerance to most phenytoin side
effects will develop over time.” “Ask your health care provider about reducing your phenytoin
dosage to minimize side effects.” “Ask your health care provider about stopping your phenytoin
if the side effects become troublesome.” “Ask your health care provider about the possibility of
using a different class of antiseizure medication.”
Answer said:
The most appropriate response the nurse should provide is:
“Ask your health care provider about the possibility of using a different class of antiseizure
medication.”
Rationale:
Phenytoin is effective but is associated with notable side effects, including:
Gingival hyperplasia
Hirsutism
Ataxia
Nystagmus
Cognitive disturbances
, Long-term risks like osteopenia or neuropathy
Because of these, patients may prefer or benefit from alternative antiepileptic drugs (AEDs)
that have a more tolerable side effect profile. There are several other AEDs available that may
be better tolerated and equally effective for complex partial seizures (e.g., carbamazepine,
levetiracetam, lamotrigine).
Why the other options are less appropriate:
“Tolerance to most phenytoin side effects will develop over time.”
→ Not accurate. Some side effects (e.g., gingival hyperplasia) do not improve with time
and may worsen.
“Ask your health care provider about reducing your phenytoin dosage…”
→ Dose reduction may lead to subtherapeutic levels and seizure recurrence.
“Ask your health care provider about stopping your phenytoin…”
→ Abrupt discontinuation of phenytoin can provoke seizures and is not advised without
a safe transition plan.
Encouraging the patient to explore alternative medications with their provider supports shared
decision-making and respects their concerns while ensuring seizure control remains a priority.
Question:
The nurse is caring for a patient who is experiencing excessive drowsiness caused by phenytoin.
The health care provider withholds the drug and prescribes a serum drug level test. For which
length of time will the nurse monitor the patient for drowsiness? 30 to 60 minutes 12 hours 24
to 42 hours 10 days
, Answer said:
The correct answer is:
24 to 42 hours
Rationale:
Phenytoin has a long half-life, which is typically 22 hours, but can range from 7 to 42 hours,
especially at higher doses due to its nonlinear (zero-order) pharmacokinetics. This means that
once the drug is discontinued, it can take 24 to 42 hours (or even longer in some individuals)
for the serum levels to decrease significantly and for side effects like drowsiness to subside.
Why the other options are incorrect:
30 to 60 minutes: Too short; phenytoin has a slow onset and long half-life, so effects will
not resolve this quickly.
12 hours: Still too short to see significant reduction in drug levels.
10 days: Unnecessarily long; phenytoin levels and associated symptoms usually begin to
improve within 1–2 days after stopping the drug.
Therefore, monitoring for 24 to 42 hours is appropriate to observe improvement in drowsiness
caused by phenytoin.
Question:
Which condition is most likely to require lower dosing and closer monitoring to prevent drug
toxicity in a patient taking phenytoin? Hepatitis Pneumonia Anemia Gastroesophageal reflux
Answer said:
Question:
A patient with complex partial seizures is prescribed phenytoin to control recurrent seizures,
but the patient reports being reluctant to take the drug long term because of its side effects.
Which information would the nurse provide this patient? “Tolerance to most phenytoin side
effects will develop over time.” “Ask your health care provider about reducing your phenytoin
dosage to minimize side effects.” “Ask your health care provider about stopping your phenytoin
if the side effects become troublesome.” “Ask your health care provider about the possibility of
using a different class of antiseizure medication.”
Answer said:
The most appropriate response the nurse should provide is:
“Ask your health care provider about the possibility of using a different class of antiseizure
medication.”
Rationale:
Phenytoin is effective but is associated with notable side effects, including:
Gingival hyperplasia
Hirsutism
Ataxia
Nystagmus
Cognitive disturbances
, Long-term risks like osteopenia or neuropathy
Because of these, patients may prefer or benefit from alternative antiepileptic drugs (AEDs)
that have a more tolerable side effect profile. There are several other AEDs available that may
be better tolerated and equally effective for complex partial seizures (e.g., carbamazepine,
levetiracetam, lamotrigine).
Why the other options are less appropriate:
“Tolerance to most phenytoin side effects will develop over time.”
→ Not accurate. Some side effects (e.g., gingival hyperplasia) do not improve with time
and may worsen.
“Ask your health care provider about reducing your phenytoin dosage…”
→ Dose reduction may lead to subtherapeutic levels and seizure recurrence.
“Ask your health care provider about stopping your phenytoin…”
→ Abrupt discontinuation of phenytoin can provoke seizures and is not advised without
a safe transition plan.
Encouraging the patient to explore alternative medications with their provider supports shared
decision-making and respects their concerns while ensuring seizure control remains a priority.
Question:
The nurse is caring for a patient who is experiencing excessive drowsiness caused by phenytoin.
The health care provider withholds the drug and prescribes a serum drug level test. For which
length of time will the nurse monitor the patient for drowsiness? 30 to 60 minutes 12 hours 24
to 42 hours 10 days
, Answer said:
The correct answer is:
24 to 42 hours
Rationale:
Phenytoin has a long half-life, which is typically 22 hours, but can range from 7 to 42 hours,
especially at higher doses due to its nonlinear (zero-order) pharmacokinetics. This means that
once the drug is discontinued, it can take 24 to 42 hours (or even longer in some individuals)
for the serum levels to decrease significantly and for side effects like drowsiness to subside.
Why the other options are incorrect:
30 to 60 minutes: Too short; phenytoin has a slow onset and long half-life, so effects will
not resolve this quickly.
12 hours: Still too short to see significant reduction in drug levels.
10 days: Unnecessarily long; phenytoin levels and associated symptoms usually begin to
improve within 1–2 days after stopping the drug.
Therefore, monitoring for 24 to 42 hours is appropriate to observe improvement in drowsiness
caused by phenytoin.
Question:
Which condition is most likely to require lower dosing and closer monitoring to prevent drug
toxicity in a patient taking phenytoin? Hepatitis Pneumonia Anemia Gastroesophageal reflux
Answer said:
