Epilepsy Flashcards
General principles of anti-epileptic therapy
- goal is no seizures, no side effects (cannot cure epilepsy)
- time required for drugs to become therapeutic
- consider efficacy (types of seizure), safety, drug interactions, side effects, and monitoring when choosing which drug to use
- blood testing (baseline liver and kidney function; monitor levels)
- levels can be affected by many things (brand vs. generic, tobacco, alcohol, drug interactions)
- combo therapy may be needed (careful for additive SE)
- can treat more than seizures (neuropathic pain, migraines, headaches, mood stability, insomnia)
SE common to all anti-seizure meds
drowsiness, dizziness, unsteadiness, clumsiness
always report rash (Stevens Johnson possibility)
bone loss (consider Calcium with Vit D supplement)
- tolerance to some SE may develop over several weeks
- start low, go slow with dosing
Traditional agents
phenytoin (dilantin, phenytek)
valproate (depakote)
carbamazepine (tegretol, carbatrol)
Newer agents
oxcarbazepine (Trileptal) lamotrigine (Lamictal) levetiracetam (Keppra) gabapentin (Neurontin) pregabalin (Lyrica) topiramate (Topamax) tiagabine (Gabitril) zonisamide (Zonegran)
- levels not well established, baseline and PRN may be done
- wider therapeutic index
- typically better tolerated, fewer interactions, and less monitoring required
Phenytoin/Fosphenytoin (Dilantin/Cerebyx)
Uses: seizure, nerve pain
Levels: 10-20mcg/mL, or 1-2mcg/mL free drug
SE: n/v, constipation, appetite changes, hair growth, gum overgrowth, leukopenia, bleeding problems, Stevens Johnson syndrome, may cause kidney problems
DDI: antacids, acetaminophen, CBZ, phenobarbital, VPA, BCPs, ibuprofen, theophylline
Misc: levels can be changed by nutritional status (ETOH, TF, change in brand); capsule coating may be found in stool; take with food for GI upset
Valproate/Valproic Acid (Depakote/Depakene)
Uses: seizures, migraine prevention, bipolar mania
Levels: 50-100mcg/mL or higher
SE: weight gain, nausea, diarrhea, abdominal cramps, hair loss, low platelets, rash, liver failure/pancreatitis
DDI: PHT, clonazepam, diazepam, phenobarbitol, PHT, CBZ, chronic ASA, inc’d sedation with ETOH and other sedating drugs
Misc: do not take if serious liver dx/LFTs should be tested esp during first six months of treatment
Carbamazepine (Tegretol/Carbatrol)
Uses: seizures, nerve pain, bipolar disorder
Levels: 4-12mcg/mL
SE: vision changes, sedation/tiredness, n/v, low blood factors (platelets, WBCs), rash, sun sensitivity
DDI: warfarin, steroids, theophylline, BCPs, quinidine, cimetidine, clarithromycin, fluvoxamine, diltiazem, erythromycin, propoxyphene, verapamil, antidepressants (inc’d SE)
Misc: grapefruit juice increases drug levels; do not use if allergy/sensitive to TCAs; coating may be found in stool
Oxcarbazepine (Trileptal)
Uses: seizure, nerve pain, mood stabilizer
SE: HA, nausa, double vision/vision changes, rash, low blood sodium
DDI: BCPs, lamotrigine, phenytoin
Misc: better tolerated than carbamazepine; beware if allergic to carbamazepine
Lamotrigine (Lamictal)
Uses: seizures, nerve pain, migraines, mood disorders
SE: rash**, more likely with rapid increases or patients taking valproic acid, more common in children; HA, nausea, blurred or double vision; less sedating than other seizure meds
DDI: carbamazepine, phenytoin, methsuximide, oxcarbazepine, phenobarbitol, primidone, rifampin, sertraline, valproic acid
Misc: sound-alike errors
Levetiracetam (Keppra)
Uses: seizures
SE: anxiety/depression, emotional lability, mood changes, infection/cold, general weakness, HA
DDI: phenytoin
Misc: almost completely renally eliminated; nearly 100% bioavailability
Gabapentin (Neurontin)
Uses: seizures, nerve pain, mood disorders
SE: weight gain, eye movements or vision changes, tremor, numbness in extremities (most improve after several weeks)
DDI: antacids, phenytoin
Misc: typically well-tolerated; little effect on other anti-seizure meds, liver, or blood; almost completely renally eliminated
Pregabalin (Lyrica)
Uses: seizures, neuropathic pain, anxiety, social phobia
SE: drowsiness/dizziness, weakness/uncoordinated movement, tremor, difficulty with concentration/attention, HA, blurred vision, weight gain, dry mouth
DDI: not metabolized- no CYP450 interactions, not protein bound, additive impairment of cognitive and motor function with other CNS medications
Misc: schedule V controlled substance (suggestion of physical dependence), almost completely renally eliminated
Topiramate (Topamax)
Uses: seizures (adults and children), migraines
SE: cognitive SE, hesitance in speech and psychomotor slowing, tingling in fingers and toes, difficulty walking, weight loss (appetite decrease), kidney stones; more cognition changes, less blood and liver side effects
DDI: BCPs, acetazolamide, digoxin, carbamazepine, phenytoin, valproic acid
Misc: drink lots of fluids, take with or without food (with to decrease SE)
Tiagabine (Gabitril)
Uses: seizures, nerve pain
SE: dizziness, depression, weight gain, anxiety, weakness, flu-like syndrome, diarrhea, vomiting, tremor, difficulty concentrating
DDI: carbamazepine, phenytoin, phenobarbitol, primidone, valproic acid
Misc: take with food, *can cause seizures in people with no hx of seizures
Zonisamide (Zonegran)
Uses: seizures, nerve pain
Levels: 10-40mcg/mL
SE: behavioral problems in children, violence/nightmares, agitation/irritability, HA, loss of appetite, stomach discomfort, difficulty concentrating, kidney stones, rash, leukopenia, bleeding problems, Stevens Johnson, decreased sweating (overheating)
DDI: carbamazepine, phenytoin, valproic acid, phenobarbitol
Misc: do not use if allergic to Sulfa drugs (this is a Sulfa drug), do not use if hx of kidney problems; drink lots of fluids
