A patient who has been taking phenobarbital for epilepsy begins ...

[vicotolentino]

A patient who has been taking phenobarbital for epilepsy begins taking valproic acid (Depakote) as adjunct therapy. The nurse notes that the patient is very drowsy. What will the nurse do?
 
  a. Explain to the patient that tolerance to sedation eventually will develop.
  b. Notify the prescriber, and request an order to reduce the dose of phenobarbital.
  c. Notify the prescriber of the need to increase the dose of valproic acid.
  d. Request an order for liver function tests to monitor for hepatotoxicity.

Question 2

A nurse is completing a discharge plan for a 24-year-old patient who will begin taking phenytoin. Which information is important to teach this patient?
 
  a. She may stop taking the drug when she is seizure free for a year.
  b. Taking the medication will ensure that she no longer has seizures.
  c. She may need to discontinue the drug if serious side effects occur.
  d. She should be sure to use an effective contraceptive method.

[scottmt]

Answer to Question 1

ANS: B
Valproic acid competes with phenobarbital for drug-metabolizing enzymes and can increase plasma levels of phenobarbital by approximately 40. When this combination is used, the dose of phenobarbital should be reduced. Increasing the dose of valproic acid would compound the problem. Patients taking phenobarbital alone experience sedation, which diminishes as tolerance develops. Liver toxicity is a rare adverse effect of valproic acid and is marked by symptoms of nausea, vomiting, and malaise, not drowsiness.

Answer to Question 2

ANS: D
Because antiepileptic drugs can harm a fetus, female patients of childbearing age should be counseled about the use of contraceptives, which may also have drug-to-drug interactions with the antiepileptic drugs. Patients should be counseled that withdrawal of a seizure medication should be done only with the advice of their prescriber and not just when a certain period of time has passed without seizures. Taking a seizure medication is not a guarantee that seizures will not occur; managing seizures often requires experimenting with several different medications. Patients should report side effects and, if they are serious, should discontinue a drug but only under the guidance of their prescriber.