AED and Seizure Drugs Flashcards
(74 cards)
1
Q
Diazepam drug class
A
- Benzodiazepine
2
Q
Diazepam MOA
A
- Works on GABA receptors –> CNS depression
3
Q
Half life of diazepam?
A
- Very short
- 2-4 hours
4
Q
Contraindications of diazepam
A
- Overall very safe
- Contraindicated in liver toxicity
5
Q
Can diazepam be used as an AED?
A
- No
- Anti-seizure
- Patients develop tolerance to it
6
Q
Emergency doses of diazepam
A
- 0.5 mg/kg IV bolus as needed
- 1 mg/kg per rectum
- Repeat every 30 sec if no seizure resolution
- May do a CRI
7
Q
What can happen with repeated doses of diazepam?
A
- Tolerance can develop
8
Q
How many mL approx of diazepam for:
Small dog
Medium dog
Large dog
A
Small: 1 mL
Medium: 2 mL
Large dog: 3-5 mL
9
Q
What if you have a continued need for diazepam?
A
- Consider CRI
- # doses /hr –> CRI rate
- If you gave 4 doses of 2 mL each in 1 hr, the CRI rate is 8mL/hr
10
Q
What is the diazepam still isn’t working?
A
- Propofol –> stops physical manifestations
- Gas anesthesia –> stops physical manifestations
11
Q
Precautions with diazepam
A
- Light sensitive
- No IM administration
- Doesn’t play well with others (precipitation/binding)
- Binds to plastic (only one catheter)
12
Q
Phenobarbital MOA
A
- Acts on GABA receptors
- Prevents ionized calcium influx at presynaptic terminals
13
Q
Metabolism of phenobarbital
A
- Metabolized by the liver
14
Q
Protein binding of phenobarbital
A
- Large portion is protein bound
-
15
Q
Starting dose of phenobarbital
A
- 2.5 - 3 mg/kg PO BID
- Loading dose usually done too
- IV formulation
16
Q
Route of phenobarbital
A
- Oral but also IV
17
Q
Half life of phenobarbital and how long to reach steady state?
A
- Half life is 2-3 days
- Takes 10-14 days to reach steady state
18
Q
Therapeutic levels of phenobarbital
A
- 15-45 µg/mL
- Target range is 15-40 (<35 µg/mL)
19
Q
Side effects of phenobarbital
A
- Sedation**
- PU/PD
- Ataxia
- Polyphagia
- TRANSIENT
20
Q
Toxicities possible with phenobarbital
A
- Blood dyscrasias –> neutropenia, thrombocytopenia
- Liver toxicity**
- Dermatologic reactions (sloughing skin and pseudolymphoma can happen)
21
Q
When is PB contraindicated?
A
- Hepatic dysfunction or disease
22
Q
What levels are concerning for PB?
A
- Levels greater than 35
23
Q
What blood work should be done with PB and when?
A
- Before starting: CBC/CHem/UA; bile acids to show normal liver function
- After starting, PB level in 14 days and CBC/Chem in 1-6 months
- Routine monitoring is CBC/Chem/UA/Bile acids/PB level q6 months
24
Q
Metabolism of PB again
A
- Liver metabolism
- Induces cytochrome P450
25
What can happen with PB metabolism over time?
- Decreased value over time possible because PB induces Cytochrome P450 and can metabolize it quickly
26
Effect of PB on liver, thyroid panel?
- Elevated liver values (ALP>>>ALT; run a bile acids if worried)
- He also measures albumin because if it decreases a lot, he wants to check it
- Thyroid panel will show euthyroid sick
27
Which medications should you be careful with when using phenobarbital?
- Enzyme inhibitors like ketoconazole and chloramphenicol
28
Potassium bromide MOA
- It's a salt that mimics chloride
| - Hyperpolarization of neurons
29
Protein binding of KBr
- None
30
Excretion route of KBr?
- Urine!
31
Half life of KBr in the dog and cat
- 28 days in dogs
| - 10 days in cats
32
Steady state of KBr in the dog and cat
- 4-5 months in dogs
| - 6 weeks in cats
33
Dose of KBr and loading possibility?
- DOse is 25-35 mg/kg PO SID
| - Loading is possible but not ideal because it is quite salty
34
Therapeutic range of KBr
- can you go higher than the therapeutic range?
- 1-3 mg/mL
| - Okay to go higher if no side effects
35
Contraindications of KBr
- Kidney disease caution (excreted in urine)
-
36
Side effects of KBr
- GI irritation! (vomiting, diarrhea, anorexia)**
- Pancreatitis
- Hyperactivity
- Better with food
- Liquid probably better than the tablet
- Ataxia, paresis, sedation
37
Formulation of KBr
- ORAL ONLY
38
Dietary considerations with KBr
- Constant diet must be had
39
What can happen with KBr given to cats?
- Fatal pulmonary edema in the cat****
40
Levetiracetam MOA
- Blocks a protein (SV2A) associated with release of NT vesicles
41
Metabolism of levetiracetam
- No hepatic metabolism
42
Side effects of levetiracetam
- Minimal to no side effects
43
Therapeutic level of levetiracetam
- Not important
| - It's very safe
44
Routes of levetiracetam
- IV/PO/rectally
45
Cost of levetiracetam
- Expensive but less monitoring required
46
Zonisamide drug class
- Sulfa based drug
47
Zonisamide MOA
- Blocks T-Type Ca channels and voltage gated Na channels
48
Where is zonisamide metabolized?
- Liver
49
Dosing interval of zonisamide
- twice a day
50
Do you increase or decrease the dose of zonisamide given with phenobarbital?
- INCREASE due to clearance
51
Dosing interval of levetiracetam?
- every 8 hours
52
Side effects of zonisamide
- Minimal effects
- Sulfa based drugs though
- Blood dyscrasias
- Renal tubular acidosis
- Acute hepatic failure
- KCS
- They say don't give sulfas to brown and black dogs
53
Gabapentin or pregabalin for seizures
- Better for pain
54
Other AED
- Gabapentin/pregabalin
- Felbamate
- Topiramate
- Meh?
55
What to think about with starting AED?
- GOALS OF THERAPY
- Cluster seizures
- Status epilepticus
- Owner conern and safety
56
AED process
- Choose one (in theory all are equal except for in humans)
- Maximize the dose of first AED (Assess therapeutic levels if applicable; side effects)
- 2nd AED once the first is maxed out!
57
ER seizure - what should you do?
- RELAX!
| - Administer valium (Big 4/patient assessment); see what happens/get history once the patient is deemed stable
58
What to do if the ER seizure has another seizure?
- Another valium dose +/- long term AED
- DON'T BE A VALIUM WIMP
Benefits for having levetiracetam
59
Sequela of seizures
- Increased ICP (look for Cushing's reflex; pupillary size/symmetry and response to light)
60
Treatment for increased ICP secondary to seizures?
- Draw edema out of the brain
| - Mannitol vs hypertonic saline
61
Mannitol drug class
- Carbohydrate
62
Mannitol MOA
- Decreases blood viscosity and decreases ICP
- Osmotic diuresis
- Decreases CSF production
- Free radical scavenger
63
Mannitol contraindications
- Dehydration or hypovolemia
| - Can give awhile also administering IVF
64
Hypertonic NaCl MOA
- Osmotic effect to decrease brain edema
65
Which drug to decrease ICP might you use in a patient that is hypovolemic?
- Hypertonic saline rather than mannitol
66
Nursing care for patients with seizures
- Eye lube PRN
- Recumbency care q4 hours
- Keep head elevated 30 degrees (jugular is a main vessel)
- Suction mouth PRN
- CN assessment
- Seizures watch with diazepam/midazolam orders
67
Know the three general types of seizures
- Generalized
- Partial
- Behavioral/psychomotor
68
Know the three general causes of seizures
- Structural
- Reactive
- Idiopathic/genetic
69
5 differentials for structural brain disease
- Tumor
- Inflammation
- Anomaly (hydrocephalus)
- Trauma
- CVA (stroke)
70
Common metabolic causes for seizures
- PSS or liver dysfunction
| - Hypoglycemia
71
Know when to start AED
Do it
72
Know the different AED
Do it
73
Know the treatment of status epilepticus
Know it
74
Know how to assess and treat ICP
- Know it
