Ch. 16/17: Anticonvulsants/Anti-Epileptics and Resp. Stimulants (Vickroy) Flashcards
When is doxapram contraindicated?
animals with seizure disorders
most common spontaneous neuro disorder in dogs
seizures
Importany questions to ask when dog has seizures
- is the reported event truly a seizure?
- can an underlying cause be identified and treated?
Things that can mimic seizures
- cataplexy/narcolepsy
- vestibular episode
- encephalitis
- exercise-induced collapse
- drug-induced dyskinesias
- cervical m. spasm
- episodic NM dz
- metabolic event
most (90%) of seizures are CNS or non-CNS?
CNS
causes of non-CNS induced seizures
- metabolic/electrolyte imbalance (hypoxia, dec. Glu/Ca/Mg, inc. K)
- liver dz
- renal failure
- drugs/toxins
- hypothyroidism
causes on CNS induced seizures
- organic brain disease (45%) (tumor, infection, head trauma) –> 2ary epilepsies
- idiopathic epilepsy (45%) –>1ary epilepsies
idiopathic epilepsy
poorly char. CNS disorder that manifests as episodes of intermittent high neuronal activity
- usually life-long*
- can be focal or diffuse in brain
- can be initiated by sensory or external stimuli
seizure
a clinical manifestation of excessive and/or hyper-synchronous neuronal discharges in the brain
-may present as episodic impairment or loss of consciousness accompanied by abnormal motor phenomena, psychic or sensory disturbances, ANS signs
convulsion
motor manifestation of seizures that involves involuntary contraction-relaxation of body muscles
epilepsy
commonly defined as 2+ seizures at least 24hrs aparts, resulting from a nontoxic/nonmetabolic cause
status epilepticus
continuous seizure activity lasting 30min or longer. Life-threatening
T/F: prolonged periods of seizure activity can produce irreversible brain damage and neuronal death and are char. by:
- extremely high use of O2 and glucose
- followed by prolonged CNS depression (unconsciousness)
- requires some form of intervention**
anti-epileptic agent curative of seizures?
NO. Only reduces the symptoms
2 general mechs. by which anti-epileptics act:
1) suppress initiation of neuronal firing in epileptiform foci
2) inhibit spread of seizure activity into normal tissues
disadvantages of AEDs
- high percentage of animals are refractory to AEDs
- high incidence of side effects
- devel. tolerance
- loss of clinical efficacy over time
empirical use
to use what works in the patient as long as it works and is tolerated by the patient and o
phenobarb fx
- long-acting barbiturate w/ anti-seizure properties
- sedative
barbiturates are classified according to:
duration of action
phenobarb mech. of action
facilitates GABA activation of GABA-A receptor and opening of Cl channels –> CNS depression (i.e. cortical motor centers)
all barbiturates are acids/bases
acids
T/F: phenobarb is DEA-controlled drug**
T. (class 4 agent)
common side effect when starting phenobarb tx of seizures
sedation (however, tolerance to this builds up over time)
long-term use of what two classes of drugs causes physical dependence?**
opiates, barbiturates. Severe withdrawal symptoms can result!
