Pre-anes Drugs(anticholinergics) Flashcards
Why we use preanesthetic drugs
Protect against features of anes drugs, or to augment anes drugs (meaning we can use less of the anes drug)
Anticholinergics are also called
Parasympatholytics
What cholinergic refers to
Acetylcholine
Role of acetylcholine
Neurotransmitter for parasympathetic NS
Diff between parasympathetic and sympathetic NS
Para: controls everyday functions, neurotransmitter=acetylcholine
Sympathetic: fight or flight
Neurotransmitter =epinephrine (adrenaline)
What anticholinergics do within the body, the mechanism of action
Block ability of acetylcholine to bind to nerves, blocks Acetylcholine receptors
When the parasympathetic NS is stimulated it produces ______ effects
Cholinergic effects
Cholinergic effects: (when acetylcholine/ PS NS stimulated it causes...) HR GI Tract Bronchi Eyes Salivary glands Tear production
HR: decrease GI tract: peristalsis stimulated Bronchi: normal size, constricted Eyes: pupils normal size, constricted Salivary glands: salivation increase Tear production: increase
Cranial nerve X (10)
What it does
Vague nerve
Innervate (supplies nerves to) parasympathetic NS, controls heart, GI Tracy, Bronchi
Things that unintentionally stimulate vagus nerve ( suppressed by using anticholinergic drugs)
Intubation, traction on organs during surgery
How anticholinergics effect the: heart
Prevents bradycardia, May cause tachycardia
How anticholinergics effect the:
GI tract
Decreases peristalsis and likelihood of V/D
Why anticholinergics bad in larger animals
can Cause bloat in cattle or colic in horses
How anticholinergics effect the:
Bronchi
Dilates, assists w respiration
How anticholinergics effect the:
Eyes
Pupils dilate (mydriasis) good for eye exams
How anticholinergics effect the:
Saltatory glands
Decrease salvation (v evident in cats, dry mouths)
How anticholinergics effect the:
Tear ducts
Decreased tear production
Which of the following do anticholinergic drugs NOT do:
Tranquilize, provide analgesia, anesthetize
All of the above
Define ileus
GI tract stasis (slow or stoppage)
What HR range is considered tachycardic in dogs and cats
Dogs: >140-160
Cats: >180-200
Contraindications (when to not use anticholinergic drugs)
Large animals, use caution in cats Bc unpredictable, tachycardic animals, heart patients, constipated animals
Full name of Atropine drug
Atropine sulfate
Atropine is extracted from what plant?
Nightshade plant ( Atropa belladonna)
2 strengths atropine comes in
.54 mg/ml or 1mg/ml
Atropine duration
1-1.5 hours
Signs of an atropine overdose
Excitement, v dry mouth, thirst, extreme or extended mydriasis, tachycardia
Reversing agent for atropine
Physostigmine
Why we can use atropine to treat organophosphate poisoning
O phosphates inhibit the enzyme that breaks down acetylcholine (acetylcholinesterase) therefore, the acetylcholine that isn’t being broken down can be blocked from receptors
atropine can also be used as an Antispasmodic medication, meaning
drug that Controls diarrhea
atropine can also be used as a Mydriatic drug, meaning
Dilates pupils
Glycopyrrolate lasts ____ as long as atropine, how long?
Twice (2-3 h)
Why glycopyrronium is used for rabbits and not atropine
Some rabbits produce atropinase (enzyme that breaks down atropine), atropine doesn’t effect them
Motion sickness anticholinergic drug (human med)
Scopolamine
Normal HR for dogs and cats
Dogs: 60-160 bpm (puppies up to 220)
Cats: 100-200 bpm
