Week 1 lecture 2 Flashcards
toxins that inhibit glycine
- receptor inhibitors: strychnine and Calycanthus spp. (ie Carolina allspice, strawberry shrub, and bubby bush)
- Receptor inhibitors (gelsemium spp. ie yellow jessamine)
- Release inhibitors (tetanus toxins)
glycine fx
- interneuron releases glycine which turns off initial neuron firing ot end muscle stimulation
- spinal nerve stim muscle cell and renshaw cell -> stem glycine and turn off muscle cell)
what happens if inhibit glycine fx
spastic paralysis
clinical signs direct glycine inhibitors
- onset 10-120 min (may find in stomach)
- anxiety, hyper responsive, tremors -> seizures
- death from resp failure 10 min -48hrs
seizures associated with glycine inhib
- begin with face neck and limbs -> sardonic grin
- saw horse stance
tx glycine inhibitors
- stablize
- DO NOT ENDUCE V+
- enterogastric lavage/ rumenotomy (anesthesia)
- barbiturates and propofol for seizure control
- supportive care, thiamin
contraindicated for tx glycine inhibitors
- ketamine
- morphine
- emetics
strychnine does what, onset, found where, affects who
- glycine receptor inhibitor
- found in rodent baits
- duration signs hrs to days, death < 30 min
- can affect any species
strychnine ADME
A- SI, rapid
D- rapid (high conc liver and kidney)
M- hepatic
E- about 48hrs
dx strychnine toxicosis
- chem analysis bait, stomach content, liver, kidney, urine
- poor prognosis
Tetanus toxin does what, onset, get how
- glycine release inhibitor
- slower onset
- clostridial wound contamination
tetanus toxin affects who
can affect any species but horses most sensitive
strychnine duration of signs
- onset min to hrs, often find in stomach bc onset so fast
Clostridium tetani exotoxins
- tetanolysin (spreading factor, makes place for bacteria to live)
- tetanospasmin (causes neurologic changes)
tetanus clinical signs
- start at puncture spread from there
- slower onset than strychnine
- sustained titanic contractions (saw horse stance, rises sardonic, pump handle tail, lockjaw horse/ human, elevated nictitating membrane)
- death from resp failure
tx tetanus
- keep animal quiet
- wound care
- antitoxin close to puncture
- teteanus toxoid at diff site than antitoxin
- muscle relaxant
tetanus prognosis horse
- horse poor prognosis (54-80% mortality)
canine tetanus prognosis
- 8-50% mortality
tetanus prevention
- sanitation/ wound care
- vac horses
GABA inhibitors include
- metaldehyde
- Penitrem (mycotoxin)
- fipronil
- methylxanthine (at high dose)
- cyclone explosives
- Amanita muscaria
- cicuta maculata
- corydalis spp.
- Dicentra spp.
gaba fx
- inhibit neurotransmitter that prevents spasm
gaba inhibitirion -> ?
- spastic paralysis
- prevents similarly to glycine inhibitors
Metaldehyde sources
- snail and slug bait
Metaldehyde ADME
* GABA inhibitor* A- gastric acid -> hydrolysis to acetaldehyde D- max plasma conc reached 1-3 hrs M- hepatic P450 E- bile, enterohepatic circulation
clin path for metaldehyde
- Elevated muscle enzymes (chemistry)
- hyperglycemia or hypoglycemia
- metabolic acidosis
tx metaldehyde toxicosis
- aggressive decontamination (emesis contraindicated if symptomatic)
- supportive and symptomatic care
- seizure control
Cicuta maculata alt name and toxic principle
- water hemlock
- gaba inhiitor
cicuta maculata onset, see what
- onset w/ in 30 min
- muscle twitch -> tetany
- often lethal
cicuta maculata toxic principle
- cicutoxin A
Sympathomimetic toxins include
- Methyxanthines
- Cocaine
- Amphetimines, cathinone, pseudoephedrine ect.
- Rasberry ketone
- Atomoxetine
- Amitraz
- Beta Agonist
Methylxanthine toxic principle
sympathomimetic toxin
adenosine antagonism
cocaine toxic principle
- sympathomimetic toxin*
- inc catecholamine release
- inc dopamine release
amphetamines, cathinone, pseudoephedrine toxic principle
- sympathomimetic toxin*
- NE, dopamine, serotonin release
- MOAI
- Na+ channel effects
- MDMA, ++ seroteonergic
Raspberry ketone toxic principle
- sympathomimetic toxin*
- enhances NE effects
Atomoxetine toxic principle
- sympathomimetic toxin*
- NE reuptake inhibitor
Amitraz toxic principle
- sympathomimetic toxin*
- a2-receptor agonist
B agonists inculde
- sympathomimetic toxin*
- facto-amine, zilpaterol
B2 agonists include
- sympathomimetic toxin*
- albuterol
- Clenbuterol
B3 agonists include
- sympathomimetic toxin*
- mirabegron
Sympathomimetic toxidrome
HAS MTH H- Hypertension A- Agitation S- Sweating M- mydriasis T- tachycardia H- hyperthermia * these are all sympathetic responses*
methylxanthines affect who, onset
- all species, but most
common in small dogs - onset min -> hrs, effects can last hrs, early mortality possible
sources methyxanthines
- coffee
- caffeine tabs
- OTC preps (cold, analgesic)
- Theophylline (tablets, elixers, tea)
- chocolate
chocolate toxicity
- methyxanthine
- baking chocolate > dark sweet chocolate > other types choclate
Methylxanthine toxicity
Caffine > theobromine > theophylline
Methylxanthine ADME
D- all compartments
M- hepatic
E- urinary
Clinical signs methyxanithine toxicosis
- onset 1-2 hrs caffeine 2-4 hrs theobromine; early see v+/ d+/ hyperactivity
- later see tachycardia, hypertension
- death 18-24 hrs bc cardiac failure and seizures
tx methyxanthine exposure
- symptomatic and supportive
- detox stable patient
- control seizures
- tx tachyarrhythmia
- keep calm
- give muscle relaxer
prognosis methylzanthine toxocis
- good if early detox
- guarded if severe (arrhythmia, seizures)
cocaine affects who, onset when
- mostly affects SA
- clin signs min -> hrs, often lethal
sources of cocaine
- street cocaine
- Crack
- Anesthetics (for eyes)
ADME cocaine
A- rapid mucosa
D- lipophilic
M- hepatic
E- urinary
clinical signs cocaine
- Hyperactive
- tremors, seizures
- ataxia
- mental obtundation
- hyperthermia
- tachycardia
- mydriasis
- salivation nd v+
dx cocaine expsore
- clin signs
- hx
- otc test kit
tx cocaine
- decontaminate large dose w/ sedation and gastric lavage
- DO NOT USE EMETICS
- supportive/ symptomatic (keep calm, control seizures, electrolytes)
cocaine toxicity prognsis
good w/ tx
