preanesthetic medications and induction agents

what are the purposes of medications and induction agents?

calm or sedate

minimize adverse effects

reduce required dose of concurrently administered agents

produce smoother inductions and recoveries

decrease pain

muscle relaxation

how are medications typically administered?

IV IM or SQ

what is the onset and duration of SQ administration?

slowest onset and longest duration

what is the onset and duration of IM administration?

somewhat faster onset and shorter duration that SQ

what is the onset and duration of IV administration?

rapid onset and shorter duration than IM or SQ

what do anticholinergics do?

decrease salivary secretions

treat/prevent bradycardia

are anticholinergics controlled or uncontrolled?

uncontrolled

atropine is an example of an _____

anticholinergic

what is the onset, peak, and duration of atropine after IM injection?

onset: 5min

peak: 10-20min

duration: 60-90min

what is the onset, peak, and duration of glycopyrrolate after IM injection?

onset: 5min

peak: 30-45min

duration: 2-3hours

Which anticholinergic is less likely to cause CNS effects because it does not cross the blood-brain barrier?

glycopyrrolate

Anticholinergics are not sedatives and have ______ CNS effects

limited

how does anticholinergics effect the cardiovascular system

they prevent bradycardia

they cause the heart rate to increase

how do anticholinergics effect the respiratory system?

they reduce secretions and produce thick mucous in the airways

what are the adverse effects of anticholinergics?

mydriasis

reduces GI motility

reduces lacrimal secretions

which anticholinergic is less likely to induce cardiac arrhythmias?

glycopyrrolate

what are the two types of anticholinergics?

atropine and glycopyrrolate

which anticholinergic is the better choice for emergency treatment for bradycardia because of its faster onset of action?

atropine

(tranquilizer/sedative) which reduces anxiety but does not decrease awareness and wakefulness

tranquilizer

(tranquilizer/sedative) which reduces mental activity and sleepiness?

sedatives

what are the 3 classes of tranquilizers or sedatives commonly used in vet med?

phenothiazines

benzodiazepines

alpha 2 adrenergic agonists

which class of tranquilizers or sedatives protect against cardiac arrhythmias or function as antiemetics?

phenothiazines

which class(es) of tranquilizers or sedatives can produce vomiting or function as a good muscle relaxant?

benzodiazepines

alpha 2 adrenergic agonists

sedatives relax tissues where?

in the pharynx

when using sedatives, which breeds should you use caution with?

brachycephalic breeds

acepromazine is a type of ____

phenothiazine

what is also referred to as the “major tranquilizer”

acepromazine

is acepromazine controlled or uncontrolled?

uncontrolled

what does water soluble mean?

it is not painful upon injection

what is acepromazine’s function?

can decrease the dose of general anesthetic required

can ease induction and recovery

True/False: phenothiazines are ideal for C-sections

False

what is the onset, peak, and duration of phenothiazines after IM injection in canine or IV injection in equine?

onset: 15min

peak: 30-60min

duration: 4-8hours in small animal + 1-3hours in equine

what is a major effect of phenothiazines?

depression

how do phenothiazines effect the CNS?

calming, sedation, reluctance to move, decreased interest in surroundings

how do phenothiazines GENERALLY effect the cardiovascular system?

can cause dose dependent tachycardia in response to hypotension

directly decreases cardiac output

what kind of antiarrhythmic effects do phenothiazines have on the cardiovascular system?

protects against ventricular arrhythmias when using other agents known to produce them

how do phenothiazines affect the respiratory system?

it doesnt

_____ can cause penile prolapse in equine

phenothiazines

phenothiazines prevent the release of _____, so you should not use them in patients undergoing allergy testing

histamines

True/False: Patients should be free of stimulation between administration and peak effect when using acepromazine

true

This drug is commonly referred to as “minor tranquilizers”

benzodiazepines

Benzodiazepines are most often used _______ for their muscle relaxant and anticonvulsant properties

in combinations with other agents

benzodiazepines may cause _____

dysphoria

what are the 3 commonly used benzodiazepines?

diazepam, zolazepam, and midazolam

True/False: Benzodiazepines should not be mixed with water soluble drugs or in a syringe with other drugs.

True