2. Preanesthetic Medication Flashcards

Question

What is azaperone/strensnil and where is it used? what's its main action

Answer 1

A butyrophenones, only used in pigs blocks dopamine and norepinephrine activity in the CNS

Answer 2

dec aggression/fighting during weaning and mixing premed and sedation for castrations anti-emetic dec malignant hyperthermia - potentially fatal genetic condition; inc metabolic rate and muscle activity in response to isoflurane, transport/handling stress common in pigs

Answer 3

Controlled, most not labelled for vet use, injectable and oral (tabs) avail.

Answer 4

anti-anxiety and calming anticonvulsant activity disorientation and excitement in yg, healthy dogs dysphoria and aggression in cats muscle fasciculation in horses ataxia or recumbency in lg animals few cardiopulmonary effects skeletal muscle relaxant no analgesia reveal is flumazenil

Answer 5

inc GABA lvls in brain - GABA is an inhib neurotransmitter

Answer 6

part of a balanced anesthesia - premed to smooth induction and recover, can combine with ketamine for induction Other common indications - antianxiety to sedation; behavioural modifer anticonvulsant for treating seizures skeletal muscle relaxant (including urethral relaxation)

Answer 7

minimal CV effects at appropriate dose does cause dose-dependent respiratory depression smoother induction and recovery decrease amount of inhalant GA req inc skeletal muscle relaxation Reversal drug class - in event of OD or adverse reaction, can give reversal agent (aka antagonist or antidotes)

Answer 8

sedation is not always reliable when used alone in animals dysphoria/excitement can occur may unmask latent aggression in some animals (animals lose inhibitions) in horses, muscle fasciculation, weakness, ataxia, do not give alone except for seizures in adults

Answer 9

avoid in pregnancy/cesarean bc it will cross the placenta and may lead to floppy baby syndrome which is skeletal muscle relaxation in the neonate and asphyxiation from relaxation of resp muscles

Answer 10

Commonly used in dogs, cats, horses and pigs indications are anticonvulsant for emerg tx of seizures anti-anxiety (noise phobias_ @ lower dose Sedation @ higher dose (must be used in combo w/ other drugs in cats/horses (and some dogs) or may cause excitement skeletal muscle relaxant relaxes urethral sphincter (blocked cats and dogs) can mix with ketamine for induction (Ketval)

Answer 11

inexpensive can be administered by IV - painful/unreliably absorbed if given IM/SQ, can give intra-rectal if seizuring patient, also available as oral tablets dose varies depending on route of admin lasts 30min-2hr may cause a prolonged hangover effect hx'cally used as appetite stimulant in cats-doesn't really work

Answer 12

controlled drug not water soluble so will form precipitate if mixed with other drugs - never use if precipiate forms), only exception is ketamine Store IV solution in glass containers as drug binds to plastic with time, keep from light Flush IV lines immediately after administering - binds to plastic and will form precipiate if still in line/veing when next drug is administered

Answer 13

contraindicated for cesarean bc of floppy baby syndrome, depressed, poor muscle tone, excessive sedation Aggressive dogs, can bring out latent aggression Used alone in horses - excitement and ataxia cats - can cause sudden liver failure, increased with increased doses (avoid use as an appetite stimulant

Answer 14

easier to use, more expensive exceptions - twice as potent, shorter acting, compatible w/ many agents as it is water-soluble, can give IM, SQ, IV, cannot use alone, not used as anti-convulsant

Answer 15

reversal agent for benzodiazepines including diazepam and midazolam binds to and blocks GABA receptors - more attraction for the GABA receptor than the benzodiazepines and therefore knocks off any benzodiazepine drug already bound to the receptor little to no effect on its own seldom used bc $$$ and short duration of action of diazepam/midazolam

Answer 16

dose-dependant sedation profound analgesia agitation or aggression when touched reaction to loud noices muscle tremors in horses cattle often lie down initial hypertension, bradycardia and pale mucus membranes followed by hypotension, dec cardiac output and a little further dec in HR

Answer 17

severe dec in HR, BP, cardiac output, tissue perfusion especially when high doses are given resp depression can be severe muscle relaxation vomiting in cats/dogs adverse GI effects (bloat and colic) hyperglycemia hypothermia inc urination premature parturition in cattle horses may sweat

Answer 18

Lg - xylazine (rompun), detomidine (dormosedan), romifidine (sedivet) Sm - dexmedetomidine (dexdomitor) reversible drug clas

Answer 19

binds to a2 adrenergic receptors activation of a2 receptors causes inhib of release of norepinephrine and dopamine dec overall symp response metabolized by liver;excreted by the kidnehys

Answer 20

overall CNS depression - dec overall ability to respond to stimuli, action is enhanced if given together with an opioid or other sedative or tranquilizer Dec symp response - bradycardia that is consistent, immediate, significant; as low as 12bpm in a large dog. Resp depression Inc parasym NS for increased GI motility (except in ruminants)

Answer 21

rapid and reversible sedation mild analgesia on its own can be used for neuroleptanalgesia which occurs when a2 agonist is combined w/ an opioid and given at a fairly high dose, a state of lack of awareness is associated w/ very heavy sedation combined with strong analgesia, used for minor procedures like suturing laceration sin horses centrally-mediated muscle relaxation

Answer 22

occures when a2 agonist is combined with an opioid and given at a fairly high dose that produces a lack of awareness associated w/ a very high sedatio combined with a strong analgesia

Answer 23

severe hypotension bc of bradycardia, dec pulse, MM very pale, don't use w/ acepromazine in SA can hypovent on room air - dec rr and resp volume, enhances resp depressant effect of other sedatives/anes, resp distress in brachycephalic dogs, ruminants sensitive to resp effects possible arrhythmias w/ some older dogs inc risk if given too fast IV or given atropine ataxia, cattle can become recumbent with dec rumen motility, risk of bloat and abortion horses can become reaction to stimuli if given alone - noise, touch emesis in catsW

Answer 24

avoid or use extreme caution in pediatrics, geriatric avoid if severely dehydrated, in shock, CV dz, severe resp dz, or severe renal dz avoid if advanced liver dz avoid or use extreme care with acepromazine bc of the severe hypotension from combo of bradycardia and vasodilation; will plummet the BP and there is no way to bring it back other than reversal however, fairly safe IF you have reserval on hand MONITOR MONITOR MONITOR

Answer 25

IM (15-20 onset), IV (1-3min onset) duration of 30-60 min don't give IV too fast or will enhance the respiratory and cardiac depression effects - when using IV, should "give to effect" only until desired degree of sedation is achieved Avoid SQ - very lipophilic, drug will bind to fat and absorption will be unpredictable (can severe delay effect) Dec effect if stressed or fearful

Answer 26

equine and bovine, a premed "standing sedation" for castrations, wound repairs, cesareans, sedates animal w/o becoming recumbent Colic - excellent visceral analgesia, 30min of analgesia if given as an epidural part of "triple drip" injectable GA; to be discussed with ketamine

Answer 27

2 concs of 20mg/ml or 100mg/ml bc lower conc in cattle b/c of inc resp and GI effects IV "to effect" Ive more pronounced heart/resp effects IM - onset is 10-15m after IM injection, duration is approx 30 min Epidural - visceral analgesia Often combined with an opioid or valium for better sedation and longer duration

Answer 28

Cattle require 1/10 of dose compared to hosees even @ recommended dose can have severe resp effects, cause GI stasis, risk aspiration pneumonia Horses - sweating, ataxia, wide-based stance, horses can become excited if used alone, never give intra-arterial in hose as it will cause excitement, seizure, collapse, avoid in neonatal foals as the lowered HR cannot maintain blood flow

Answer 29

a2 adrenergic agonist, labelled for horses similar to xylazine - visceral analgesia, give slowly IV to effect, can give alone or with opioid, severe hypotension and bradycardia twixe the duration and stronger sedation used for standing sedation never use with sulphonamides - heart failure

Answer 30

labelled for horses, sedative or premed, can use at low dose for anxiolytic(anti-anxiety) with minimal ataxia Similar to xylazine, detomidine - fast acting, long lasting, severe hypotension and bradycardia

Answer 31

SA, alpha2 adrenergic agonist sedation of 60-90 min, analgesia for 30 min For sedation for hip rads, minor procedures with local anes, quills Premed for sedation and preemptive analgesia on-going sedation if given as a CRI

Answer 32

usually give in combo with opiod better analgesia, better sedation dec the mg/kg dose of demedetomidine req - dec adverse side effects most commonly with butorphanol or buprenorphine will see more resp depression if combined with hydromorphone

Answer 33

label dose is 10x to 20x what is used in-clinic label dose intended for heavy sedation with dexmedetomidine alone when combined with opioids and/or with balanced anesthesia, only use lat 1/10 to 1/20 the labelled dose lower dose is much safer is labeled for induction at higher doses (not usually done) As animal size increases the mg/kg dose decreases

Answer 34

IV or IM IM takes 15-20 onset NEVER give SQ as the drug deposits in fat and released unpredictable give IV to effect, dogs only, do NOT give too rapidly as it can stop breathing, 1-3 min onset can give 1/2 IM, wait 15 min and give remainder IV to effect

Answer 35

profound bradycardia and resp depression (more noticable in dogs) monitor HR and BP - HR will drop significantly; 16(lg K9), 40 (sm k9), must monitor BP and pulse strength Monitor MM - will be pale but never cyanotic Monitor oxygenation - extend neck, place on flow-by 100% O2 if available place IV cath - if in doubt, place on IV fluid support

Answer 36

do NOT use with atropine - heart block, heart failure extreme caution or avoid with acepromazine - profound hypotension Extreme caution when followed by isoflurance in cats - causes more extreme vasodilation than acepromazine avoid if hypotensize, dehydrated, geriatric, debilitated

Answer 37

LA - a2 agonist (zylazine, detomidine, romifidine) a2 antagonist (yohimbine or Yobine, tolazoline or tolazine) SA - demedetomidine, reversal is atipamezole (antiseden)

Answer 38

effects specific to a2 agonists - does not affect other drugs reversal of the sedative, CV AND analgesic effects of the corresponding agent few adverse effects at clinical doses, but significant adverse effects if too much is given by inc sympathetic tone GI, neurologic and CV effects like excitement, muscle tremors, hypotension, tachycardia, salivation, vomiting, diarrhea

Answer 39

ANALGESIA! Strongest available Also a preanesthetic to give for pre-emptive analgesia, giving b4 pain occurs results in less post op analgesia required and shorter recovery times, also for sedation, dec total dose of GA required Also as an anesthetic induction - at higher doses, some opioids produce unconsciousness (uncommon) Majority have wide margin of safety at therapeutic dose (higher potency -> lower therapeutic index) Metabolized by liver w/ renal excretion so caution in yg, old, debilitated, very ill, if resp system compromised ALL CONTROLLED

Answer 40

A profound state of sedation and analgesia induced by simultaneous administration of an opioid and a sedative Ex. Dexmedetomidine + hydromorphone; Xylazine + fetanyl Commonly given for minor procedures or induction causes CNS depression to state of borderline unconsciousness, can be aroused by extreme stimulation or noise

Answer 41

IM, SQ, IV, Oral, rectal, transdermal, subarachnoid, intra-articular (joints), epideral if given IV, must be done slowly to avoid CNS stimulation

Answer 42

work by binding to opioid receptors although opioid receptors found on neurons throughout the body, analgesic and sedative effect are primarily the result of their action on receptors located in the brain and spinal cord Brain - sedation and analgesia Spinal cord - analgesia smooth muscle in the rest, GI tract, urinary tract

Answer 43

* Mu (μ) * Kappa (κ) * Delta (δ)

Answer 44

Supraspinal analgesia * Moderate to severe pain * Sedation * Respiratory depression * Bradycardia * Mioisis (mydriasis in cats) * Hypothermia (hyperthermia in cats) * Euphoria/dysphoria * GI stasis (constipation) * Urinary Retention * CRTZ (Chemoreceptor trigger zone) for vomiting * Anti-emetic at the vomiting center

Answer 45

Spinal analgesia * Mild to moderate pain * Miosis * Mild sedation * Little respiratory depression * Diuresis

Answer 46

based on which receptor they bind and whether binding causes the receptor to be turned on (agonist), partially on (partial agonist) or turned off (antagonist)

Answer 47

Pure agonists Partial mu-agonists Agonist-antagonist Pure antagonist

Answer 48

Drugs that bind to and turn on the mu-receptor may also turn on kappa receptor Provides best analgesia (treats mod to severe pain) Higher mu-receptor binding = more analgesia Also prods sedation EX> morphine, hydromorphone, oxymorphone, fentanyl, meperidine, hydrocodone, tramadol

Answer 49

For the Mu receptor (Resp depression, GI stasis, hypothermia, ocassional hyperthermia in cats) Analgesia and sedation are better if also has kappa activity highest risk of addiction

Answer 50

Binds to and PARTIALY activates the mu-receptor physiological affects - (when compared to pure agonists) less analgesia, resp depression, GI stasis, euphoria and less hypothermia Indicated for slight to moderate pain Also used to partially block the effects of a pure mu agonist that is given at the same time (acts as part reversal) Ex. Buprenorphine (partial mu-agonist; kappa antagonist)

Answer 51

Simultaneously turns on kappa-receptor (kappa-agonist) while blocking mu-receptor (mu-antagonist) physiological effects: mild analgesia, sedation, less resp depression and GI effects than pure or partial agonists, may cause dysphoria Can be used to completely block either mu-agonist or partial mu-agonist activity

Answer 52

Binds to both mu-receptors AND kappa-receptors but does not prod any activity effectively acts as a block. "reversals" EX naloxone, naltrexone, diprenorphine (M-50) is the reversal agent specifically created for etorphine (M-99)

Answer 53

resp depression - common in case of OD's, centrally-mediated; dec RR and tidal volume, also inhibs CO2-dive that stims breathing, ventilation should be monitored and O2 available Bradycardia, hypothermia, sedation Can inc brain swelling in patients with brain trauma or cerebral edema

Answer 54

Hyperthermia in certain cats is due to a mu-receptor response especially hydromorphone and can be fatal if not treated

Answer 55

Emesis - activates chemoreceptor trigger zone in the brain, often w/ 1st dose of mu-agonists in healthy pain free anims, can block/decrease with acepromazine or diazepam GI stasis (constipation), more likely with chronic use, avoid or caution in colic, bloat, FB surgeries (enterotomies) Dysphoria, excitement, hallucinations, startle response in cats Addiction - mu-receptor mediated, receptor down-regulation means may need to inc dose or dose frequency to manage chronic pain

Answer 56

Ace - Hypotension by vasodilation A2 agonist - Bradycardia (hella low HR) Opiods - resp depression

Answer 57

Antitussive (codeine, hydrocodone, butorphanol; to treat cough) Vomit (apomorphine, IM hydromorphone) Diarrhea and flatulence Miosis in dogs, mydrasis in cats/eq Excitement, dysphoria, whine/bark (dogs), inc motor activity (horse), inc sensitivity to noise Hypo/hypertension changes in urination, excess salivation panting in dogs, hyperthermia in cats, sweating in horses

Answer 58

Mu-agonists and kappa-agonists for mod-severe pain, sedation, resp depression, GI stasis, used for analgesia, sedation, premeds

Answer 59

Super mu-agonist wildlife capture 100-100000 times the activity of morphine; very low therapeutic index

Answer 60

kappa-agonist; mu antagonist mild paid and sedation, least resp depression, can block mu-agonists

Answer 61

Pure antagonist reversal agents; block mu- and kappa-receptors no effect on own, not controlled

Answer 62

Pure mu agonist Mu and kappa agonist indications "opioid standard of reference" everything is compared to it mild to mod sedation dose dependent analgesia for mod to severe pain Routes - IM, IV, SQ, PO, intra-articular, epidural Duration of 3-4hrs

Answer 63

excitement or dysphoria in cats, horses mydriasis in cats, horses drowsiness in dogs severe resp depression with high doses nausea/vomiting GI stasis (oral form is worse) Histamine release can cause systemic vasodilation

Answer 64

Pure mu agonist Mu and kappa agonist 50-100x potency of morphine Indications: neuroleptanalgesia, induction, analgesia (w/ frequent administration) Routes: IV bolus, CRI (preferred IV method), slow-release transdermal action patch, epidural Duration: 1-2 min onset; 10 min duration of action IV Usually CRI or slow release transdermal patch for analgesiaWh

Answer 65

Side effects * Defecation or constipation * Respiratory depression * Bradycardia * Hypothermia * Panting, drooling * Dysphoria, agitation * Sedation * NOT approved for food animals

Answer 66

Pure mu agonist, mu and kappa agonist indications: 5-10x the potency of morphine, mod to severe pain (visceral and somatic), pre, peri and postoperative pain control, more sedation than morphine, rarely used in lg animals bc of lack of info about efficacy or adverse side effects Duration for IV is 1-2 IM 2-4h in dogs, longer in cats SQ up to 6-8hrs Epidural 8hrs

Answer 67

reliable emetic with first dose, especially if SQ/IM diarrhea with first dose; constipation with chronic use pant, drool mydriasis in cats/horses excitement/hallucinations in cats/horses

Answer 68

Resp depression, use with caution if severe resp dz Bradycardia hypothermia in all species can cause occasional hyperthermia in cats which can be fatal In event of severe adverse reaction, can partially reverse with buprenorphine or butorphanol; can completely reverse with naloxon, naltrexone

Answer 69

Pure mu agonist, mu and kappa agonist Indication for 5-10x the potency of morphine. Mod to severe pain (visceral and somatic), low incidence of vomiting (compared to morphine or hydromorphone); other side effects similar to other pure mu agonits ~4hrs of duration (slightly longer than morphine or hydro)

Answer 70

Licensed in Canada for 0.5mg/kg IM in cats prior to spay or neuter ONLY IN CATS Extra Label Use: commonly used 0.2-0.5mg/kg administered IV, IM or SQ

Answer 71

Pure mu agonist, mu and kappa agonists Indications 1/10x morphine, mild to mod pain Routes: IM injection, NOT IV or SQ Histamine release with IV use Duration of action - 30-90min Side effects - no vomiting or bradycardia, used as premed when no vomiting is req

Answer 72

"Super mu-agonist" 500-1000x the power for morphine but shorter acting than fentanyl indications - intra-operative analgesia for dogs/cats as an infusion, induction

Answer 73

Super mu-agonist 10,000-100,000x the power of morphine Indications - wildlife capture and immobilization Potentially fatal if handler scratches/injects self - use with extreme caution so wear double gloves when handling closed bottle Reversal req naltrexone for reversal draw up BEFORE handling carfentanil

Answer 74

Partial mu agonist, kappa antagonist 1/20x morphine mild to mod pain, less sedation onset of action ~30min Routes - IV, IM, SQ, epidural or transmucosal (in cats) place in the buccal cavity or sublingual and allow absorption through the oral mucosa, will NOT work if swallowed

Answer 75

duration is 6-8hrs in dog and cat 2hrs in sheep fewer side effects than hydromorphone due to partial mu-activity, slight dysphoria reversal - higher affinity than naloxone, therefore req much high doses or infusion of naloxone to reverse buprenorphine

Answer 76

Agonist-antagonist (kappa agonist, mu antagonist) 1/2-1x morphine, mild to mod pain - analgesia and sedation via the kappa-receptor. EX. colic Sedation, antitussive, reversal of hydromorphone SA (0.5mg/ml) and LA (10mg/ml) conc

Answer 77

IV, IM, SQ, and PO No mu-receptor mediated side effects so less resp depression, no excitement, GI stasis or panting in dogs

Answer 78

butorphanol will bind to the receptor bc is has 30x the affinity for the receptor compared to hydromorphone result is to kick out the hydromorphone and/or prevent the hydromorphone from binding to receptor

Answer 79

reversal of desirable and undesirable effects of opioid agonists, partial agonist, or agonist-antagonist including sedation and analgesia - CNS and resp depression Routes of admin - IM and slow IV Effects/adverse effects - sedation, dysphoria, panting, resp depression, hypotension, bradycardia, GI effects and analgesia The action of opioid antagonists is often dramatic, causing the patient to appear nearly unaffected shortly after administration

Answer 80

pure antagonist complete reversal of both mu- and kappa- agonist, will lose all adverse effects AND all analgesia dog, cat, horses, exotics, people 1 drop under tongue of neonates after C-section to reverse resp depression of opioid given to mother Duration of action 30-40 min, will need to top-up Time of onset 2 min IV aggressive use can cause catecholamine-related cardiac arrhythmias and vasoconstriction leading to pulmonary edema

Answer 81

pure antagonist both Mu and kappa antagonist more potent than naloxone used to reverse carfentanil in wild-life - can be used intra-nasally action - longlasting (hours)

Answer 82

yur - only blocks mu-activity; adds to kappa-activity not a very strong reversal as it leaves sedation and some analgesia. WIll reverse resp depression and hypo/hyperthermia