ALLIE PUNKE PHARMACOKINETICS: ANTIEPILEPTIC DRUGS

NAME THAT ANTIEPILEPTIC Which should be titrated slowly to prevent cognitive slowing? Which is known for causing hepatotoxicity and should not be used in children less than two years of age? Combination of lamotrigine with what antiepileptic results in an increase risk of TEN?

NAME THAT ANTIEPILEPTIC Which 3 drugs did Dr. Hamilton specifically mention that are cleared by the kidneys and may require supplemental dosing after dialysis? Which essentially has very minimal drug interactions? Which is affected by antacids (causing a decrease in absorption)?

NAME THAT ANTIEPILEPTIC Which should you counsel patients about keeping hydrated to decrease a potential side effect. Which has a very long half life? Which is affected by diuretics and urinary alkalinizers? Which induces its own metabolism?

NAME THAT ANTIEPILEPTIC Which cause DRESS? Which has the same oral and IV dosing? Which cause aseptic meningitis? A patient has a Na level of 137. Excluding other potential causes, which antiepileptic drug(s) is likely to cause this?

TRUE OR FALSE You receive a call from a patient on carbamazepine who is experiencing a small rash that started this morning. You should tell her it will likely go away in a few days. If it doesn’t, then follow up with her physician. A patient experienced SJS syndrome while on carbamazepine. Switching to oxcarbazepine is likely good treatment option, but other antiepileptic drugs could be considered as well.

TRUE OR FALSE A patient is admitted to the hospital for suicide ideation. Lamotrigine is likely not the best choice, since there is an increased risk of psychiatric and behavioral symptoms with this drug. A patient with epilepsy is started on Keppra. She is also receiving estrogen/progesterone birth control. Keppra is not a good choice in this patient, since it will induce the metabolism of the birth control.

TOPIRAMATE ANTIEPILEPTIC DRUGS

TOPIRAMATE Is topiramate mostly dependent on renal or hepatic system? Does it require renal dose adjustment? Do you need a supplemental dose after dialysis?

TOPIRAMATE Why is it recommended not to stop topiramate abruptly? What is a counseling point to tell patients to reduce risk the incidence of a side effect that could be caused by topiramate?

GABAPENTIN ANTIEPILEPTIC DRUGS

GABAPENTIN AB is to be started on gabapentin. PMH includes Crohn’s disease, where he recently had to have some of his bowel removed. As long as he still has __________, gabapentin should still be absorbed. A patient is to be started on gabapentin. Due to severe GERD, she is taking pantoprazole and Tums. Is this an issue with gabapentin? A patient is on dialysis. Do we need to supplement gabapentin after dialysis?

LAMOTRIGINE ANTIEPILEPTIC DRUGS

LAMOTRIGINE A patient is to be started on lamotrigine for the first time. What would you expect the prescription directions to include to avoid serious skin reactions such as SJS? Because valproic acid can ________ the levels of lamotrigine, __________ doses should be used. A patient needs to be started on birth control. What type of birth control (if any) is there a drug interaction with lamotrigine?

LEVETIRACETAM ANTIEPILEPTIC DRUGS

LEVETIRACETAM A patient is to be started on levetiracetam for the first time. In the directions, it says to start at 500 mg BID and titrate to 1500 mg BID. The patient asks you if this is actually necessary? If it is, explain why. Is it excreted mostly by renal or hepatic? Does it require supplemental dose following dialysis?

LEVETIRACETAM In patients with what types of disorders or symptoms would levetiracetam not be the best antiepileptic drug to use? What is a key distinguishing factor that makes levetiracetam so unique in comparison to other antiepileptic drugs?

VALPROIC ACID ANTIEPILEPTIC DRUGS

VALPROIC ACID Valproic acid can increase the levels of several drugs. Specifically, we are especially concerned about the interaction with this antiepileptic, as it can increase the risk of TEN. What is a major side effect (a BBW even exists to warn about this)? Valproic acid can also cause what other disease state?

OXCARBAZEPINE ANTIEPILEPTIC DRUGS

OXCARBAZEPINE If a patient experienced a rash while on carbamazepine, it is likely that they’ll also react to oxcarbazepine? What is the incidence (if any)? True or False: Because oxcarbazepine induces its own metabolism, the dose will eventually need to be increased to compensate for this effect.

CARBAMAZEPINE ANTIEPILEPTIC DRUGS

CARBAMAZEPINE What is really unique about carbamazepine (and is responsible for the variable half life)? What are the major side effects of carbamazepine?

PHENOBARBITAL ANTIEPILEPTIC DRUGS

PHENOBARBITAL A patient was started on phenobarbital 10 days ago. Today, the level is 2. What should we do? A patient was started on phenobarbital 50 days ago. Today, the level is 7. What should we do? How long does it take to get to steady state? Therapeutic range is what?

GOOD LUCK! QUESTIONS ABOUT THIS OR LAST WEEK’S SESSION?