-
Chronic seizure disorders are classified as...
-
Extracranial, Underlying causes for seizures (10):
- Hypocalcemia
- Hypoglycemia
- Hypoxia
- Hypo/Hypernatremia
- Hyper-triglyceremia
- Hepatic Encephalopathy
- Uremic Encephalopathy
- Polycythemia
- Thiamin Def
- Toxins
-
Symptomatic, Intracranial, Underlying causes for seizures (9):
- Head Trauma
- Meningoencephalitis
- Hydrocephalus (other congenital)
- Cerebral Neoplasia
- Lysosomal Storage Disorder
- Acquired Cryptogenic Epilepsy
-
Which type of seizure is most common in dogs?
Generalized tonic-clonic (Grand-Mal)
-
Status Epilepticus-
When P fails to recover btw repeated tonic-clonic seizures, lasting for >30 mins
-
Primary goals to inhibit seizures (3):
- Increase seizure threshold
- Reduce the spread of seizure discharge to surrounding neurons
- Reduce Discharge of Focus (less common)
-
Drug therapy efficacy... Complete Control: Partial Control: Little/No Control:
- Complete: 50%
- Partial: 25%
- Little/None: 25%
-
Drugs commonly used for status epilepticus:
-
Drugs traditionally used for long term control of seizures:
- Phenobarb
- KBr
- (Primidone-hepatotoxic, Valpronic and Phenytion are limited in vet med)
-
New drugs for long term control of seizures (5):
- Felbamate
- Gabapentine (neurontin)
- Levetiracetan (Keppra)
- Zonisamide (Zonegran)
- Pregabalin (Lyrica)
-
Which Anticonvulsant is metabolized in the liver?
Phenobarb
-
Which Anticonvulsant has active metabolites?
Diazapam
-
What are the active metabolites of Diazapam?
-
1/2 Life of... (Dogs/Cats)
Phenobarb:
Bromide:
Diazapam:
- Phenobarb: 2-3d/1-3d
- Bromide: 15-45d/10-11d
- Diazapam: 3hrs/15-20hrs
- (Dogs/Cats)
-
Which Anticonvulsant is reabsorbed and excreted unchanged in the kidney?
Bromide
-
Side Fx of Diazapam (4):
- Desation
- Ataxia
- Polyphagia
- ACUTE HEPATIC NECROSIS
-
Side Fx of Bromide(5):
- Vomiting
- Sedation
- Polyphagia
- PU/PD
- Pelvic Limb Ataxia/Weakness
- (Rare: Hyperactivity, pancreatitis, cutaneous lesions, Inflammatory Lung Dz)
-
Tx Strategy for dogs
- 1. Phenobarb
- 2. Pehnobarb + KBr
- 3. KBr alone
-
Side Fx of Penobarb(7):
- Sedation
- Polyphagia
- PU/PD
- Pelvic Limb Ataxia/Weakness
- Hepatotoxic (+ALT & ALKP)
- Alter Bone Metab (Hematologic Fx)
- Increased metab of various subs (+T4/FT4, Abx)
-
Tx strategy for cats
- 1. Phenobarb
- 2. Benzodiazapine
- 3. 3rd level drugs (primidone is toxic, and KBr=bronchial irritation)
-
By which mechanisms does phenobarb supress seizures?
- Increase threshold
- Decrease Spread
-
How does phenobarb work?
- GABA mediated inhibition
- Inhibits glutamate activity
- Reduces Ca fluxes across mem
-
How does Diazapam work?
GABA Mediated Inhibition
-
-
What drung enhances the action of GABA?
Benzodiazapine
-
If Status Epilepticus doesn't respond to 2-3 doses of Diazapam, then admin...
Phenobarb IV
-
Drawbacks of using Propofol to Tx Seizures (2):
- Hypotension
- Respiratory Depression
- (Expensive)
-
In case of strychnine, ____ induces Status Epilepticus
Pentobarbital
-
How long until Steady State obtained with administration of....
Phenobarb:
Br:
- Phenobarb: 10-16 days
- Bromide: 3-4 Months
-
T1/2 of...
Phenobarb:
Br:
Diazapam:
- Phenobarb: 47-74/25-76 hrs
- Br: 15-45/10-11DAYS
- Diazapam: 3.2/15-20 hrs
- (Dogs/Cats)
-
Which Anticonvulsants are contraindicated w/ Liver Dz?
-
Which Anticonvulsants are contraindicated w/ Lung Dz?
Bromide
-
Metabolism of Phenobarb
Liver
-
Metabolism of Bromide
Unchanged in kidneys (reabsorbed= long 1/2 life)
-
Metabolism of Diazapam
- 1st Passage
- Active Metabolites (Nordiazapam & Oxazapam)
-
Diazapam's Active Metabolites
-
Which anticonvulsants have an additive effect?
Bromide and Phenobarb
-
Other/New Anticonvulsants (5):
- Febamate
- Gabapentine
- Levitiracetam
- Zonisamide
- Pregabalin
-
Alt to Benzodiazapam for cats
Clonazepam
-
Ways to protect brain function (5):
- Barbituates
- O2 therapy
- Mannitol
- Lasix
- Elevate head 30o
-
Ways to support systemic function (5):
- Fluids
- O2Maint. Temp
- Maint HR & BP
- Ventilation (rarely)
-
Most commonly used anticonvulsant
Phenobarb
-
Congener of Phenobarb:
Primidone
-
Primidone is converted to...
-
Most potent elevator of threshold
Benzodiazapam
-
By which mechanisms do effective anti-convulsives suppress seizures?
- Increase Threshol
- Inhibit Spread
-
Which drugs is ineffective in dogs when given PO?
Diazapam
-
Which drug requires a loading dose?
KBr/NaBr
-
During sever convulsions (i.e. strychnine toxicosis) when diazapam is ineffective, what other drugs should be administered?
|
|
