Anticonvulsants Flashcards by Hannah McMahon

Anticonvulsants/ AEDs are used for what?

1) long term management of chronic epilepsy
2) management of seizures not caused by epilepsy

How well did you know this?

Not at all

Perfectly

What is off-label use of anticonvulsants? Hint: 4

1) anxiety
2) bipolar disorder
3) chronic pain
4) migraines

How well did you know this?

Not at all

Perfectly

What will happen if a pt abruptly stops taking their anticonvulsant?

It can trigger recurrence of seizures

How well did you know this?

Not at all

Perfectly

What are the mechanisms of action of anticonvulsants?

1) sodium channel blockers
2) calcium channel blockers
3) GABA enhancers
4) glutamate blockers

How well did you know this?

Not at all

Perfectly

Mechanisms of actions:

Sodium channel blockers

Prevent the rapid firing of neurons
prevent return of channel to active state – stabilizes them – inactive state

How well did you know this?

Not at all

Perfectly

Mechanisms of action:

Calcium channel blockers

Slow down the flow of calcium into cells, limiting the development of action potentials

How well did you know this?

Not at all

Perfectly

Mechanisms of action:

GABA enhancers

Enhances inhibitory effects, making neurons less likely to fire

How well did you know this?

Not at all

Perfectly

Mechanisms of action:

Glutamate blockers

Prevent excitatory signaling by blocking glutamate

How well did you know this?

Not at all

Perfectly

How do we select which medication is used for Tx of seizures?

By the classification of the seizure and epilepsy

How well did you know this?

Not at all

Perfectly

What type of seizures are broad spectrum meds used for?

Effective for Tx of focal & generalized seizures

How well did you know this?

Not at all

Perfectly

What type of seizures are narrow spectrum meds used for?

Used primarily for focal-onset seizures (including focal which evolve to B/L convulsive seizures)

How well did you know this?

Not at all

Perfectly

List 9 things to base selection of meds for seizure Tx off of

1) efficacy
2) tolerability
3) presence of comorbidities
4) pharmacokinetic profile
5) potential drug-drug interactions
6) ease of use
7) cost
8) age
9) gender

How well did you know this?

Not at all

Perfectly

List 10 AEDs thats mechanism of action is Na+ channel blockers

1) carbamazepine
2) oxcarbazepine (trileptal)
3) eslicarbazepine
4) felbamate
5) lamotrigine
6) lacosamide (vimpat)
7) phenytoin (fosphenytoin (IV))
8) topiramate
9) valproate
10) rufinamide

How well did you know this?

Not at all

Perfectly

List 6 AEDs thats mechanism of action is glutamate blockers

1) topiramate
2) zonisamide (zonegran)
3) perampanel
4) felbate
5) levetiracetam
6) Brivaracetam (PO, IV only > 16 yrs)

How well did you know this?

Not at all

Perfectly

List 6 AEDs thats mechanism of action is calcium channel blockers

1) ethosuxmide
2) gabapentin
3) lamotrigine (lamictal)
4) pregabalin
5) valproic acid
6) zonisamide

How well did you know this?

Not at all

Perfectly

List 6 AEDs thats mechanism of action is GABA enhancers

1) benzodiazepines
2) barbiturates
3) valproic acid (depakote)
4) gabapentin
5) pregabalin
6) ethosuximide

How well did you know this?

Not at all

Perfectly

How do AEDs that act as Ca channel blockers work?

Ca going in during cells resting state facilitates development of an action potential; however these meds slow the flow of Ca++ into the cell

How well did you know this?

Not at all

Perfectly

What do AEDs that act as Ca channel blockers inhibit?

Slow depolarization which is needed for spike-wave bursts
help “lock the channel”

How well did you know this?

Not at all

Perfectly

How do AEDs that act as GABA enhancers work?

May enhance Cl- influx which makes cell more negative & harder for cell to generate AP
some ↓ metabolism of GABA so more is available

How well did you know this?

Not at all

Perfectly

How do AEDs that act as glutamate blockers work?

Bind glutamate (excitatory neurotransmitter)
Glutamate has 5 binding sites

How well did you know this?

Not at all

Perfectly

What do many AEDs require?

Drug monitoring

How well did you know this?

Not at all

Perfectly

List 3 patient education tips when using AEDs

1) take as prescribed
2) NEVER stop taking on own
3) side effect management

How well did you know this?

Not at all

Perfectly

How does Phenytoin (Dilantin) work?

Na+ channel blocker
Works to stabilize neurons from becoming too excited
Stops spread of seizure activity in motor cortex

How well did you know this?

Not at all

Perfectly

Which AED is highly (90%) protein-bound drug?

Phenytoin (Dilantin)

How well did you know this?

Not at all

Perfectly

List 3 indications for giving Phenytoin

1) tonic-clonic seizures 2) status epilepticus 3) prophylaxis for surgery

What is the therapeutic range of Phenytoin?

10-20 mcg/ mL **very narrow; monitor drug levels**

Routes of admin for Phenytoin

PO, IM, or IV

If Phenytoin is administered IV how should it be given?

**Normal saline** Over 30-60 min b/c it can be very irritating to veins

Important precautions with tube feeds when using Phenytoin

Need to STOP feeds for 2 hrs before & after administration

List 7 neuro side effects of Phenytoin

1) drowsiness 2) ataxia 3) irritability 4) visual problems 5) peripheral neuropathy 6) N/V 7) headache

List 2 CV side effects of Phenytoin

1) hypotension 2) arrhythmias

List 3 other side effects of Phenytoin

1) suicidal thoughts 2) skin rash (Steven Johnsons) 3) Gingival hyperplasia

Phenobarbital (solfoton, luminal) is classified as a ____

Barbiturate

How does Phenobarbital work?

Inactivates fast Na channels leading to enhanced GABA effects & decreased glutamate release

Describe the half-life on Phenobarbital

Long half-life

List 6 side effects of phenobarbital

1) sedation 2) diplopia 3) cognitive skill impairment 4) respiratory depression 5) hypotension 6) hyperactivity & inattention in children

Phenobarbital can lead to ____ ____

physical dependence (habit forming)

Carbamazepine (tegretol) works similar to what other AED?

Phenytoin

Carbamazepine is the drug of choice for what types of seizures?

Partial & generalized tonic-clonic seizures

Carbamazepine (tegretol) inhibits

Spread of seizure activity

Where should carbamazepine be kept?

**DRY** location (not a bathroom)

List 2 off-label uses for carbamazepines

1) trigeminal neuralgia 2) bipolar disorder

Carbamazepine can interact with what & cause reduction in effectiveness

Oral contraceptives

What types of seizures should carbamazepines NOT be used for?

Absence & myoclonic seizures (can make them worse)

What is therapeutic range of carbamazepine?

4-12 mcg/ mL

List 5 neuro side effects of carbamazepines

1) headache 2) diplopia 3) ataxia 4) drowsiness 5) sedation

List 5 other side effects of carbamazepines

1) N/V 2) hyponatremia 3) ↓ blood counts (neutropenia/ thrombocytopenia) 4) rashes (including steven-johnsons) 5) increase suicidal thoughts

What should carbamazepines be taken with?

Food

What labs should be monitored for someone taking Carbamazepines? **Hint: 4**

1) sodium 2) CBC 3) LFTs 4) BUN/ Cr (esp. in those w/ renal impairment)

What AED has the same efficacy as Carbamazepine but is better tolerated?

Oxycarbazepine (trileptal)

When is Oxycarbazepine used?

As adjunctive therapy or monotherapy for partial seizures in children & adults

Oxycarbazepine can make what two types of seizures worse?

1) absence 2) myoclonic

Oxycarbazepines can reduce effectiveness of ____ ____ & increase risk of _____ thoughts

Oral contraceptives; suicidal thoughts

How does Valproic acid/ Valproate (Depakote) work?

Inactivation of fast Na+ channels; GABA enhancer

List 5 indications for giving Valproic acid/ Valproate

1) absence seizures 2) myoclonic seizures 3) tonic-clonic seizures 4) partial seizures 5) neonatal seizures

Off-label use of Valproic acid/ Valproate

Used to control Sx of acute mania in bipolar disorder

What other AED can Valproic acid be given with?

Phenytoin

Is Valproic acid/ Valproate considered broad or narrow spectrum?

Broad spectrum

List 6 side effects of Valproic acid/ Valproate

1) N/V 2) sedation/ dizziness 3) pancreatitis 4) increased ammonia levels 5) thrombocytopenia 6) suicidal thoughts

Valproic acid/ Valproate can cause ____ toxicity

liver toxicity (hepatotoxicity)

Narrow therapeutic range of Valproic acid/ Valproate

50-100 mcg/ mL

List 3 labs you need to monitor in a patient taking Valproic acid/ Valproate

1) LFTs 2) CBC 3) ammonia levels

Routes of administration for Valproic acid/ Valproate

Oral or IV

What is important to keep in mind when giving Valproic acid/ Valproate IV?

**Must be diluted w/ at least 50 mL NSS or D5W** Give over an hr (no more than 20 mg/ min)

What should Valproic acid/ Valproate be given with?

Food

How does Gabapentin (Neurontin) work?

Thought to act on the Ca channels to ↓ glutamate & ↑ GABA in the brain

Indications for giving Gabapentin

1) Partial seizures 2) New onset of epilepsy

What type of seizure can become worse if Gabapentin is used for Tx?

Myoclonic seizures

List 6 off-label uses for Gabapentin

1) Chronic neuropathic pain 2) Anxiety 3) Hot flashes/ night sweats 4) Headaches 5) Hiccups 6) Alcohol withdrawal

What type of dose range does Gabapentin have?

Wide dose range (no monitoring needed)

List 9 side effects of Gabapentin

1) Fatigue 2) mental cloudiness 3) leukopenia 4) edema 5) weight gain 6) emotional lability (mood changes) 7) tremors 8) GI side effects 9) suicidal thoughts

Cautions for using Gabapentin **Hint: 2**

1) Use reduced dose in renal pts 2) Cautious use in those with an addiction Hx

What do doses of Gabapentin look like when used for pain control?

Doses will be very high