pharmacology test #1 study

what are the primary sympathetic nervous system stimulators?

epinephrine & norepinephrine

what vital sign differences will you see with sympathetic nervous system stimulators?

heart rate and respiratory rate increases

alpha-1 receptors

smooth muscle

alpha-2 receptors

skeletal muscle

beta-1 receptors

heart

beta-2 receptors

skeletal blood vessels and bronchioles

dopaminergic receptors

kidney, heart, mesenteric blood vessels

what do beta blockers do?

slow the heart rate down, decrease blood pressure

how do most autonomic drugs alter the events?

- mimicking neurotransmitters

- interfering with neurotransmitter release

- blocking attachment of neurotransmitters to receptors

- interfering with the breakdown or reuptake of neurotransmitters at the synapse

cholinergic agents

drugs that stimulate receptor sites mediated by acetylcholine

what do cholinergic agents do?

aid in diagnosis of myasthenia gravis

reduce IOP of glaucoma

stimulate gi motility

treat urinary retention

control vomiting

antidotes for neuromuscular blockers

what are common direct-acting cholinergics?

metoclopramide (reglan)

pilocarpine

bethanechol

carbamylcholine

acetylcholine

metoclopramide (reglan)

controls vomiting and promotes gastric emptying

pilocarpine

reduces IOP of glaucoma and treats KCS

bethanechol

treat GI and urinary tract atony

carbamylcholine

treats GI atony

what are common indirect-acting (anti cholinesterase) agents?

edrophonium

neostigmine

physostigmine

organophosphate compounds

demecarium

pyridostigmine

edrophinium

diagnosis myasthenia gravis

pyridostigmine

treats mysthenia gravis

what are the adverse side effects of cholinergics?

bradycardia

hypotension

heart block

lacrimation

diarrhea/vomiting

intestinal rupture

what do cholinergic blocking agents (anticholinergic) do?

blocking acetylcholine of the parasympathetic nervous system (parasympatholytic)

decrease gi motility

pupil dilation before ophthalmic exams

relieve ciliary spasms of the eye

treatment of sinus bradycardia

atropine

anticholinergic

- parenteral or ophthalmic

- preanesthetic

- treat sinus bradycardia

methscopolamine

anticholinergic

- treats diarrhea

glycopyrrolate

similar to atropine, longer duration of action/used as preanesthetic

what are adrenergic (sympathomimetic) agents used for?

stimulate heart during cardiac arrest

reverse hypotension and bronchoconstriction of anaphylactic shock

strengthen heart during CHF

correct hypotension

treat urinary incontinence

reduce capillary bleeds (vasoconstriction)

prolong effects of local anesthetics (vasoconstriction)

treat glaucoma

epinephrine

adrenergic agent

- stimulates all receptors

- increase heart rate

- vasoconstriction in skin

- vasodilation in muscle

- bronchodilation

- increased metabolic rate

norepinephrine

adrenergic agent

- mostly alpha, some beta

- vasopressor to increase blood pressure

isoproterenol

adrenergic agent

- pure beta

- bronchodilator to treat asthma

phenylephrine

adrenergic agent

- alpha stimulator

- nasal vasoconstrictor, increase blood pressure

dopamine

adrenergic agent

precursor of epinephrine and norepinephrine

phenylpropalamine (proin)

adrenergic agent

urinary incontinence treatment

dobutamine

adrenergic agent

- beta 1 agonist

- short term treatment of heart failure

albuterol

adrenergic agent

- beta agonist

- bronchodilation

what are adverse side effects of adrenergic (sympathomimetic) agents?

tachycardia

hypertension

nervousness

cardiac arrythmias

pulmonary edema in overdose

phenoxybenzamine

adrenergic (sympatholytic) blocking agent (alpha blocker)

- hypotensive agent

acepromazine

adrenergic (sympatholytic) blocking agent (alpha blocker)

- tranquilizer

- vasodilation

what type of patient should you use caution using acepromazine in?

seizure patients (lowers seizure threshold) and stallions (penile prolapse)

prazosin

adrenergic (sympatholytic) blocking agent (alpha blocker)

- treat urethral spasms during obstruction

yohimbine (yobine)

adrenergic (sympatholytic) blocking agent (alpha blocker)

- reversal for xylazine

atipamezole (antisedan)

adrenergic (sympatholytic) blocking agent (alpha blocker)

- reversal for dexmedetomidine

propranolol

adrenergic (sympatholytic) blocking agent (beta blocker)

- treat cardiac arrhythmia and HCM

- decreases heart rate

- decreases blood pressure

- decreases cardiac output

timolol

adrenergic (sympatholytic) blocking agent (beta blocker)

- ophthalmic drug for glaucoma

atenolol

adrenergic (sympatholytic) blocking agent (beta blocker)

similar to propranolol

what do CNS drugs do?

used to tranquilize or sedate an animal for restraint or anesthetic procedures

categories of cns drugs

tranquilizers

barbituates

dissociatives

opioid/antagonists

prevent or control seizures

inhalants

cns stimulants

euthanasia agents

what are tranquilizers used for?

calm patients

suppress brain activity and awareness

muscle relaxation

decrease dose of anesthetic requirements

ease of placing an intravenous catheter

promote smooth induction and recovery

what are phenothiazine derivatives used for?

tranquilizer

- prevention and treatment of vomiting

- relief of mild puritis

what is the most common phenothiazine derivative?

acepromazine

what are adverse side effects for phenothiazine derivatives?

hypotension

hypothermia

does acepromazine treat anxiety?

no, it only sedates

what are benzodiazepine derivatives used for?

sedation/anxiety relief

seizure treatment (diazepam/valium or midazolam/versed)

appetite stimulant

what are commonly used benzodiazepine derivatives?

diazepam (valium)

midazolam (versed)

zolazepam (1/2 telazol)

alprazolam (xanax)

how should you store diazepam (valium) or midazolam (versed)?

not in a syringe or solution bag

- absorb into plastic

protect from light

what do you use alpha-2 agonists for?

provides sedation, analgesia, muscle relaxation, anti anxiety

xylazine hydrochloride (rompun)

alpha-2 agonist

- used as an emetic

- reversed with yohimbine

dexmedetomidine (dexdomitor)

alpha-2 agonist

- used alone or in combination with opioids +/- dissociative

- reversed with atipamezole (antisedan)

what is the oldest category of cns depressants still used in vet med?

barbiturates

how are barbiturates categorized?

duration of action

what is a long acting barbiturate?

8-12 hour durations

- phenobarbital (anticonvulsant)

what is a short acting barbiturate?

45 minutes to 1.5 hours

- pentobarbital (general anesthesia)

what is an ultra short acting barbiturate?

5-30 minutes

- thiobarbiturates

not available in United States

ketamine

dissociative agents

- class III controlled substance

- often combined with tranquilizers

tiletamine

dissociative agents

- 1/2 of telazol

- combined with a benzo

what to remember about dissociative drugs?

lube the eyes because they will stay open

burn when given IM

opioid

any compound derived from opium poppy alkaloids and synthetic drugs with similar pharmacologic properties

what are the four classes of opioids?

mu

kappa

sigma

delta

mu - group of opioids

pain regulating areas of the brain; analgesia, euphoria, respiratory depression, physical dependance, hypothermia

- typically class II

kappa - group of opioids

cerebral cortex and spinal cord; analgesia, sedation, depression, miosis

what are naturally occurring narcotics?

opium and morphine sulfate

what are synthetic occurring narcotic agonists?

oxymorphone

butorphanol

meperidine (demerol)

fentanyl

hydrocodone (hycodan)

etorphine

butorphanol tatrate

synthetic opioid agonist

antitussive, analgesic, preanesthetic

fentanyl

synthetic opioid agonist

class II comes in injection and transdermal patches

hydrocodone (hycodan)

synthetic opioid agonist

class III antitussive agent

apomorphine

synthetic opioid agonist

dopamine agonist

- emetic

methadone

synthetic opioid agonist

codeine

synthetic opioid agonist

buprenorphine

synthetic opioid agonist

partial mu agonist-antagonist

works great in cats

tramadol

synthetic opioid agonist

class IV

recently become a controlled substance

opioid antagonists

block the effects of opioids

bind with opiate receptors, displace narcotic molecules already present, and prevents future binding

naloxone

pure opioid antagnost, no agonist activity

used to reverse opioids

neuroleptanalgesics

consists of an opioid and tranquilizer combined

used for sedation, anesthesia, restraint

drugs given to prevent or control seizures

diazepam

midazolam

phenobarbital

levetiracetam (keppra)

zonisamide (zonegran)

potassium bromide and gabapentin are adjunctive medications

what is minimum alveolar concentration (MAC)?

measure of potency

- lower numbers indicate more potency

partition coefficient

ration of the number of molecules of an anesthetic gas that exist in two phases (blood/gas)

vapor pressure

indicates how volatile (unpredictable) it is and the maximum concentration that can be achieved

isoflurance

inhalant anesthetic

- rapid induction and recovery

- stable heart rhythm, no decrease in cardiac output

sevoflurance

inhalant anesthetic

- less odor than iso

- rapid induction and recovery

- need higher percentages

nitrous oxide

inhalant anesthetic

- adjunct to other inhalant anesthetics to speed induction

- cannot be used as sole agent

propofol

miscellaneous cns drug

- short acting hypnotic used for induction

- given to effect

- great for c-sections as it does not cross placental barrier

- apnea can occur if given too quickly

glyceryl guaiacolate or guaifenesin (Guailaxin)

miscallenous cns drug

- skeletal muscle relaxant that has effect on neurons of the spinal cord and brainstem

- used primarily in equine medicine for anesthesia

doxapram

cns stimulant

- activates respiratory system by stimulating respiratory centers in the medulla

- stimulate respiration in newborns and use during or after anesthesia

monoamine neurotransmitters

dopamine, norepinephrine, serotonin

antianxiety medications

benzodiazepines (diazepam, alprazolam, lorazepam)

azapirones (buspirone)

dexmedetomidine oromucosal gel (sileo)

used for noise phobias

tricyclics

antidepressant

- amitriptyline and clomipramine

serotonin reuptake inhibitors

aka ssris

antidepressant

- fluoxetine, sertraline, paroxetine

monoamine oxidase-b inhibitors

antidepressant

selegeline -> treats cognitive dysfunction

synthetic progestins

antidepressant

depo-provera (medroxyprogesterone)

what are common miscellaneous behavioral pharmacotherapy drugs?

clorazepate

gabapentin

methylphenidate (ritalin)

pentobarbital

barbiturate

euthanasia agent

class II substance