Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Anesthesiology > Premedication Drugs > Flashcards

Premedication Drugs Flashcards

1
Q

Purposes of premedication

A
  1. Sedation, analgesia
  2. Anesthetic sparing effect
  3. Reduction of stress and catecholamine release
  4. Redution of O2 demand
  5. Increased safety for animals and staff
  6. Decrease parasympathetic tone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Drugs classes used in premedication

A
  1. Anticholinergics
  2. Alpha 2 agonists
  3. Phenothiazines and butyrophenones
  4. Benzodiazepines
  5. Opioids
  6. Antihistamines and antibiotics
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

MOA Anticholinergics

A

Inhibit parasympathetic nervous system

Antagonize muscarinic acetylcholine receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Anticholinergic drugs

A

Atropine and glycopyrrolate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Atropine

A

Lipid soluble
Absorbed well IM/SC/PO
Crosses BBB and placenta

Dose: 0.01-0.04 mg/kg IV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Glycopyrrolate

A

Water soluble
Absorbed slowly IM/SC/PO
Does not cross BBB and placenta

Slower than atropine, half the dosage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Indications for Anticholinergics

A

Need for increasing the heart rate (opioid induced or reflex bradycardia)
Need for decreasing salivation and bronchial secretions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Contraindications for Anticholinergics

A
  • Tachycardia
  • Hyperthyroidism
  • Most heart diseases
  • Narrow angle glaucoma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Cardiovascular side effects of Anticholinergics

A
  1. Second degree AV block (bradycardia and cardiac arrect)
  2. Tachycardia
  3. Hypertension
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What part of the heart do Anticholinergics effect?

A

SA node particularly

AV node is weakly effected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Medetomidine/Atropine disadvantages

A

Vasoconstriction, tachycardia, hypertension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Other effects of anticholinergics

A
  1. Relaxes lower esophageal sphincter
  2. Mydriasis
  3. Bronchodilation
  4. Dries airway secretions
  5. intestinal paralysis
  6. CNS toxicity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What drug treats anticholinergic CNS toxicity?

A

Physostigmine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which Anticholinergic is preferred in rabbits?

A

Glycopyrrolate

Atropine is broken down too quickly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which class has the strongest available sedative ability?

A

Alpha-2 Agonists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Do Alpha-2 agonists have specific antagonists?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

MOA: Alpha-2 agonists

A

Competitive agonist of alpha-2 receptor (suppress NE release)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Location of alpha-2 receptors

A
  1. CNS presynaptic membrane
  2. Postsynaptic membrane
  3. Extra-synaptic sites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Alpha-2 agonist presynaptic effects

A
  1. Sedation
  2. Analgesia
  3. Reduction of sympathetic outflow from brain
  4. Reduction of stress response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Alpha-2 agonist postsynaptic effects

A

Vasoconstriction of arteries and veins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Alpha-2 agonist extra synaptic effects

A
  1. Inhibition of lipolysis
  2. Inhibition of insulin release- hyperglycemia
  3. Natural ligand with Epinepherine
  4. Interaction with stress response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Alpha-2 agonist CNS effects

A
  1. Species specific sedative (weak in pigs)
  2. Some analgesia- synergism with opioids
  3. Muscle relaxation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Alpha-2 agonist Cardiovascular effects

A
  1. Strong vasoconstriction- high SVR and BP
  2. Reflex bradycardia- low CO and tissue perfusion
  3. May develop hypotension
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Should alpha-2 agonists be used with atropine?

A

No- reflex bradycardia does not need to be treated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Alpha-2 agonist Respiratory effects
1. Mild respiratory depression (decreased RR) 2. Increase in tidal volume 3. Increased upper airway resistance 4. V/Q mismatch in horses and ruminants- decreased PaO2 5. Bronchoconstriction, lung edema, and hypoxemia in Ruminants
26
Which alpha-2 agonist is contraindicated in sheep?
Xylazine
27
Alpha-2 agonist GI effects
1. Decreased salivation 2. Decreased lower esophageal sphincter tone 3. Decreased GI motility 4. May induce vomiting- esp cats
28
Xylazine side effect in cattle
Uterine contractions and abortion
29
Alpha-2 agonist indications
1. Sedation of aggressive animmals 2. Sedation in the ICU 3. Sedation to manage post-op airway obstruction 3. Prevention/tx of seizures
30
Alpha-2 agonist contraindications
1. Too young or too old 2. Hemodynamic instability 3. Severely debilitated patient 4. Not suitable for most at risk patients
31
Alpha-2 agonist drugs
1. Xylazine 2. Medetomidine 3. Dexmedetomidine 4. Detomidine 5. Romifidine
32
Alpha-2 antagonist drugs
1. Atipemezole 2. Yohimbine 3. Tolazoline
33
Which alpha-2 antagonist should be used to counteract alpha-2 agonist drugs?
Atipemezole
34
Alpha-2 antagonist are always given what route?
IM Emergency can be given IV
35
Which alpha-2 antagonist is the most specific?
Atipemezole
36
Xylazine dosages
Cattle ~10% of horses dose | Small ruminants between dog and horse dose
37
Xylazine duration
20-40min
38
Detomidine species used
Large animals
39
Detomidine route and duration
IM/IV/sublingual 90-120min
40
Romifidine species used
Horses
41
Romifidine route and duration
IM/IV 45-90min
42
Romifidine benefits
Produces less ataxia than xylazine and is preferred for standing procedures
43
Medetomidine dosing
USA- body surface EU- body weight Typically used in combination to reduce doses/adverse effects
44
Dexmedetomidine is ______ times as potent as medetomidine.
2x
45
Does dexmedetomidine have the same effects as medetomidine?
Yes
46
Medetomidine is a mixture of which two drugs?
Levomedetomidine and Dexmedetomidine
47
Phenothiazine drugs
Acepromazine, chlorpromazine, etc.
48
Which receptors do phenothiazines act on?
Dopamine, serotonine, alpha-1, histamine
49
Acepromazine duration
4-8 hours depending on dose 48 hours for liver patients
50
Phenothiazine CNS effects
1. Sedation (weaker than apha-2 agonists) 2. No analgesia 3. Antiemetic 4. Mild respiratory depression
51
Phenothiazine Cardiovascular effects
Vasodilation and hypotension (esp in hypovolemic animals) Monitor bp very closely
52
Phenothiazine Other effects
1. Antihistamine 2. Antiarrhythmogenic 3. Inhibit platelet function 4. Penile prolapse in horses (not much of an issue but avoid anyway) 5. Seizures (older drugs)
53
Phenothiazine indications
1. Mild sedation for premed or post-op 2. prevention/treatment of opioid dysphoria 3. Prevention of emesis (morphine induced) 4. Sedation for dogs with laryngeal paralysis 5. Enhance xylazine in horses
54
Contraindications for phenothiazines
1. Hypovolemia or hemodynamic instability 2. Age extreme patients 3. Von-Willebrand disease 4. Boxers 5. Breeding stallions
55
Butyrophenones are very similar to which other class?
Phenothiazines
56
Butyrophenone drugs
Droperidol and azaperone
57
T/F: Butyrophenones are more likely to cause behavioral side effects.
True
58
T/F: Butyrophenones are more likely to cause the same adverse effects as phenothiazines.
False, they cause less profound of the same side effects
59
Benzodiazapine MOA
GABA receptor agonists
60
Benzodiazapine effects
Sedative, anticonvulsant, muscle relaxant Minimal CV and respiratory effects No analgesia
61
Benzodiazapine drugs
Agonists- diazepam, midazolam, zolazepam Antagonists- flumazenil, sarmazenil
62
Premedication mixtures with benzos
Opioids, alpha-2 agonists or both
63
Induction mixtures with benzos
Dissociative anesthetics, barbituates, propofol
64
Diazepam characteristics
- Lipid soluble - Formulated in propylene glycol or lipid emulsion - low chemical compatibility
65
Diazepam administration
Slowly IV Poor absorption and pain on IM injection
66
Diazepam duration and metabolism
Metabolized in liver 1-4 hours
67
Midazolam characteristics
- Water soluble | - Good chemical compattibiliy
68
Midazolam differences from diazepam
- More potent - Shorter acting - Inactive metabolites - Can be given IM/IV or MM
69
Opioid receptors
Mu: strong analgesia, respiratory depression, dependency Kappa: weaker analgesia Sigma: weaker analgesia Location: brain, spinal cord, peripheral nerves, inflamed organs
70
Opioid classifications
Full agonists: activate receptors and trigger full tissue response Partial agonists: activate receptors but do not trigger full tissue response even at high doses Antagonists: bind to receptors but do not activate them Concentration dependent
71
Opioid CNS effects
1. Analgesia (acute pain) 2. Decreasing MAC of inhalants (species dependent) 3. Sedation (better with more pain) 4. Excitation, dysphoria 5. Tolerance 6. Dependence
72
Opioid vomiting mechanisms
Stimulation of chemoreceptor trigger zone outside the BBB After entering the brain they will inhibit the vomiting center Water soluble > lipid soluble
73
Opioid cardiovascular effects
No direct negative inotropy or vasodilation May reduce sympathetic outflow and indirectly reduce BP Increase parasymathetic tone to decrease HR Suitable risk for most patients, improves Cv function be allowing reduction in anesthetic doses
74
Opioid respiratory effects
Depression of respiration not as strongly as humans/primates Antitussive effects, may inhibit airway protective reflexes
75
Opioid GI effects
Nausea, vomiting, defecation, obstipation, spasm of the sphincter or oddi
76
Opioids other effects
``` Hypothermia Post off hyperthermia Myosis in dogs, mydriasis in cats Inhibition of urination Noise sensitivity ```
77
Opioid indications
Premedication Perioperative analgesia Treatment of acute and chronic pain
78
Opioid administration
ALL THE WAYS
79
Morphine
- cheap and strong analgesic - water soluble - Slow onset, long duration - High individual variety in elimination - metabolized in liver - may case histamine release esp in high doses
80
Hydromorphone, oxymorphone
- Strong analgesics (full mu) - duration ~4hr - Reliable metabolism - better choice than morphine
81
Methadone
Similar to hydromorphone Also acts as NMDA antagonist
82
Fentanyl
- Strong analgesic (full mu agonist) - fast onset of duration - may accumulate after long infusions - bolus or CRI dosages
83
Remifentanil
- Similar to fentanyl with potentcy - Short acting and does not accumulate - disruption of administration may trigger strong pain - boluses may cause sudden bradycardia
84
Butorphanol
- Partial antagonist on mu and kappa (mau antagonize full mu agonists) - weak and short acting analgesic - may worsen pain - used for premed w/ benzodiazepines or alpha-2 agonist
85
Buprenorphine
- partial mu agonist - stronger analgesic than butorphanol - long acting slow onset - often used in cats (less excitement and easy admin)
86
Tramadol
- weak analgesic - inhibits NE and serotonin reuptake - not scheduled - can be given PO
87
Opioid antagonists
Naloxone: small animals to reverse respiratory depression Naltrexxone: long acting, antagonize wild animals after long acting opioids
88
Antibiotics
- Cefazolin - Amoxicillin clavulic acid Give IV 20min pre-op and every 90-120min
89
Antihistamines
Diphenhydramine: H1 antagonist H2 antagnoist: ranitidine, famotidine, cimetitide- increase pH of stomach Given pre-men for mast cell tumor removal

Anesthesiology (27 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions