Epilepsy

seizure

What occurs as a sudden electrical disturbance of cerebral cortex, neurons fire rapidly and repetitively for seconds to minutes?

epilepsy

What occurs as disturbed regulation of electrical activity in the brain (chronic), characterized by two or more seizures w/o a clear precipitating factor (separated by >24hrs)?

· Hyperventilation

· Photostimulation

· Physical/emotional stress

· Sleep deprivation

· Sensory stimuli

· Hormonal changes

What are some epilepsy triggers?

Bupropion, Tramadol, Venlafaxine, Theophylline, High dose phenothiazines, carbapenems, illicit drugs, benzodiazepine

What are some medication triggers for epilepsy?

· Surgery- if focus can be IDed and surgical removal is appropriate

· Vagal nerve stimulation- reserved for pts unresponsive to medications

· Ketogenic diet- high in fat, low in carbs

What are some non-pharm treatment options for epilepsy?

two adequate trials of two AEDs

What classified epilepsy as drug resistant?

•2-5 years seizure free

•Single seizure type

•Normal neurologic exam and IQ

•EEG normalized with treatment

What is the criteria for attempting discontinuation of epilepsy drugs?

•Go slow (6 weeks to 3 months per drug)

•Remove one agent at a time

•Seizure activity may not indicate failure of withdrawal

What is the process of discontinuing epilepsy drugs?

Valproic acid & Carbamazepine

What two epileptic drugs are teratogenic for women of child bearing age?

decrease estrogen/progesterone

Enzyme inducers will have what affect on OCs?

Lamotrigine

OCs decrease _____ concentration.

valproate and levetriacetam

There has been no interaction seen (yet) with _______ and ______ w/ OCs.

Vitamin K

What should be supplemented the last month of pregnancy when taking AEDs with enzyme inducing properties?

Sedation, ataxia, diplopia

What are some possible GENERAL dose related AEs?

Rash, hepatotoxicity, hematologic toxicities

What are some general idiosyncratic AEs that are usually the result of discontinuing drugs?

peripheral neuropathy, weight gain, osteoporosis

What are the possible GENERAL chronic ADEs?

LAMOTRIGINE

What medication is MC associated with serious rash and AEDs?

•Phenytoin

•Primidone

•Felbamate

•Topiramate

•Perampanel

•Phenobarbital

•Oxcarbazepine

•Carbamazepine

What are some enzyme inducers?

Valproate

What is the 1 enzyme inhibitor?

•Inducer – drug interactions

•Autoinduction – dose titration

What are the pharmacokinetics associated with carbamazepine?

Serious skin reactions, aplastic anemia (d/c if WBC <2500/mm3 or ANC <1000/mm3)

What are the Boxed warnings associated with carbamazepine?

sodium, thyroid function, CBC

What should be monitored for a pt on carbamazepine?

HLA-B 1502

When considering using the drug Carbamazepine in Asians what must be tested prior due to predisposition to SJS and TENS?

hyponatremia, hypothyroidism

What are the chronic AEs associated with carbamazepine?

· induced and inhibitor

· Can decrease levels of oral contraceptives

What are the PKs associated with oxcarbazepine?

more frequent hyponatremia

What are the AEs associated with oxcarbazepine?

ethosuximide

What medication is used for absence seizures?

protein binding 90%, saturable absorption (michaelis- Menten)--> small doses can have disproportional effects

What are the PKs associated with Phenytoin?

o Ocular – diplopia, nystagmus, blurred vision

o CNS – lethargy, fatigue, incoordination, drowsiness

o Cardiovascular – hypotension, bradycardia, cardiac arrhythmias

What are the possible dose related AEs in these categories when using phenytoin?

Ocular

CNS

CV

phenytoin

What medication is associated with gingival hyperplasia?

purple glove syndrome

What is the term for extravasation causing phenytoin crystals to deposit into muscle?

Fosphenytoin

What medication can be used IM or IV instead of phenytoin to prevent purple glove syndrome to occur?

bipolar disorder, migraine prophylaxis

What are the other uses for valproic acid besides epilepsy?

liver failure, pancreatitis, fetal harm

What are the boxed warnings for valproic acid?

weight gain, hair loss, tremor (“fat, bald, and shakey”)

What are the possible AEs associated with valproic acid?

valproic acid

What medication does NOT interfere with oral contraceptives?

inhibitor

Is valproic acid an enzyme inducer or inhibitor?

decrease

If a pt is on oral contraceptives containing estrogen how will lamotrigine levels be affected?

serious skin rxns including SJS/TEN

What are the boxed warnings associated with Lamotrigine?

restart dosing method-- do NOT just go back to the dose the patient was on

If a pt skips or stops lamotrigine for over 7d what is recommended?

Levetriacetam

What medication has NO significant DIs but has warnings of psychiatric rxns like agitation, irritability, depression?

fatigue, drowsiness, dizziness, ataxia, nystagmus, tremor, WG, diplopia, edema, euphoria

What are some AEs associated with gapapentin?

mild euphoria (controlled substance), edema

What are some AEs associated with pregabalin?

weight loss, migraine prophylaxis

What are some other uses for topiramate?

can decrease effectiveness of oral contraceptives at doses >=200mg/d

What is the DI with topiramate?

topiramate

What anti-epileptic medication is associated with AE- birth defects (cleft lip and palate)?

zonisamide

What anti-epileptic medication should NOT be used with sulfonamides?

lacosamide

What anti-epileptic medication has these warnings:

prolonged PR interval and increased risk of arrythmias

status epilepticus

What type of epilepsy is termed as abnormally prolonged seizures lasting longer than 30 minutes OR recurrent seizures without an intervening period of consciousness between seizures?

Benzodiazepines (Lorazepam or Midazolam)

What is the 1st line tx for status epilepticus?

Lorazepam

What medication used to treat status epilepticus is IV and has a LONGER duration?

midazolam

What medication used to treat status epilepticus is IV/IM and has a SLOW onset?