Download 4-15-2016 PPT

PHARMACOKINETICS:
ANTIEPILEPTIC DRUGS
ALLIE PUNKE ([email protected])
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?
QUESTIONS ABOUT THIS OR
LAST WEEK’S SESSION?
GOOD LUCK!