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RUSVM Pharmacology I > Opioids > Flashcards

Flashcards in Opioids Deck (136)
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1
Q

Opioids

A

Agonist at opioid receptors (anything that can be displaced by naloxone)

2
Q

Opiates

A

Naturally occurring drugs (alkaloids) extracted from opium

3
Q

Narcosis

A

Stupor bordering general anesthesia - Used to be induced with opium - Morphine-type drugs are narcotics

4
Q

Natural (opiates) Opioids

A

Alkaloids from seed pods of opium (Papaver somniferum) Ex-Morphine

5
Q

Semisynthetic Opioids

A

Substitution of chemical radicals in place of hydrogen atoms at hydroxil positions of morphine Ex- “-morphone” Oxymorphone, Hydromorphone, apomorphone

6
Q

Synthetic Opioids

A

Completely manufactured in lab Ex- Fentanyl, Carfentanyl, Butorphanol

7
Q

Opioid receptor types

A

mu, delta, kappa

8
Q

Mu opioid receptor - endogenous ligand

A

B-endorphins - Endomorphins

9
Q

Mu Opioid receptor- Main effects

A

Analgesia - Respiratory depression - Euphoria

10
Q

Delta opioid receptor- endogenous ligand

A

Enkephalins

11
Q

What receptors do enkephalins bind to?

A

Delta opioid receptors

12
Q

Delta opioid receptor - Main effects

A

Analgesia Hormonal effects

13
Q

What type of receptor do B endorphins and endomorphins bind to?

A

Mu opioid receptor

14
Q

Kappa Opioid receptor Endogenous ligand

A

Dynorphin

15
Q

What opioid receptor does dynorphin bind to?

A

Kappa opioid receptor

16
Q

Kappa opioid receptor - Main effects

A

Analgesia Dysphoria Diuresis

17
Q

Full U agonists

A

Activate u-opioid receptors completely

18
Q

Partial agonists

A

Activate some opioid receptors, but not completely

19
Q

Mixed agonist-antagonists

A

Activate some opioid receptors and block others

20
Q

Full Antagonists

A

Block ALL opioid receptors

21
Q

Opioid Scheduling Schedule II

A

Most full u agonists

22
Q

Opioid scheduling Schedule III

A

Buprenorphine

23
Q

Opioid scheduling Schedule IV

A

Butorphanol Tramadol

24
Q

Opioid Agonists- MoA -Activation of opioid receptors

A

Reduces adenylate cyclase activity & cAMP synthesis Hyperpolarizes neurons - K+ efflux Reduces neurotransmitter release by decreasing Ca++ influx

25
Q

Opioid agonists Pharm Effects Overview

A

Not potent sedative Is neuroleptanalgesic Not much muscle relaxation Excellent analgesia Respiratory depression Antitussive

26
Q

Opioid agonists Pharm effects at CNS

A

Behavioral changes Motor activity Thermoregulation Pupil size Antitussive Vomiting

27
Q

Opioid agonists - @CNS Effect on behavioral change

A

CNS depression (dogs, monkey, humans) CNS stimulation (cat, horse, ruminant, pig) - Dysphoria

28
Q

Opioid agonists- @CNS Effect on motor activity

A

Depression of motor area (dogs) Increased locomotor activity (horses)

29
Q

Opioid agonists- @CNS Effect on thermoregulation

A

Hypothermia (dogs, rabbit, monkey) Hyperthermia (cat, ruminant, horse)

30
Q

Opioid agonists- @CNS Effect on Pupil size

A

Miosis (dogs) - stimulate oculomotor nucleus to increase parasympathetic tone Mydriasis (cats, horse, sheep) - excitement & increased sympathetic activity

31
Q

Opioid agonists- @CNS Antitussive effect

A

Central inhibition of the cough center

32
Q

Opioid agonists- @CNS Vomiting effect

A

Related to route of administration (IM>IV) Emetic stimulation of CRTZ Anti-emetic effect on vomiting center

33
Q

Opioid agonists- Analgesic effect

A

Supraspinal Spinal Peripheral (?)

34
Q

Opioid agonists- Respiratory system effects

A

Small doses - Increased panting (dogs) at Larger doses- depress respiration

35
Q

Opioid agonists Larger dose, depressed respiration effects

A

Reducedd sensitivity to PaCO2 Healthy vs. diseased animals Anesthetics Bronchoconstriction (histamine release)

36
Q

Opioid agonists Cardiovascular system effects Dogs

A

Dogs- -Bradycardia & vasodilation, maybe reflex tachycardia, vagal stimulation -Cerebral vasodilation (PaCO2)–> Increased intracranial blood pressure

37
Q

What should be used to treat cardiovascular system effects in dogs due to opioid agonists?

A

Can treat with anticholinergics if necessary

38
Q

Opioid agonists GI tract effects

A

Vomiting Decreased Motility (central & peripheral)

39
Q

Opioid agonists Effects of decreased GI motility

A

Delayed gastric emptying Decreased GI secretions Increased intestinal fluid absorption Slowed peristalsis Constipation Sphincter spasm

40
Q

Opioid agonists Slowed peristalsis description

A

Contraction of segmental muscles Relaxation of longitudinal muscles

41
Q

Opioid agonists Urinary tract effects

A

Decreased micturition (u agonists) Increased micturition (K agonists)

42
Q

What effect do U agonists have on the urinary tract?

A

Decreased micturition

43
Q

What effect do K agonists have on the urinary tract?

A

Increased micturition

44
Q

Opioid agonists Describe effects leading to decreased micturition

A

u- agonists Increased sphincter tone Stimulation of ADH release

45
Q

Opioid agonists Describe effects leading to increased micturition

A

K- agonists Inhibition of ADH release

46
Q

Opioid agonists Other effects

A

Histamine release (IV morphine, dogs) Immune system modulation Addiction (Schedule II, III, IV)

47
Q

Opioid agonists Absorption

A

IM or IV Variable PO absorption (20% morphine, first-pass metabolism) Epidurally, intrathecally CRI Transdermal (fentanyl) Transmucosal (buprenorphine)

48
Q

Which Opioid agonist is absorbed transdermally?

A

Fentanyl

49
Q

Which Opioid agonists is absorbed transmucosally?

A

Buprenorphine (remember Cat after surgery)

50
Q

Opioid agonists Distribution

A

Well-distributed Plasma protein binding differences Solubility differences

51
Q

Opioid agonists Metabolism

A

Hepatic (morphine) vs. non-hepatic (remifentanil)

52
Q

Opioid agonists Hepatic metabolism

A

Morphine Conjugation with glucaronic acid Conjugation with sulfuric acid (cats)

53
Q

Opioid agonists Hepatic metabolism Conjugation with glucaronic acid process

A

Morphine–> Morphine-3-glucuronide & morphine-6-glucuronide (active metabolites - analgesic)

54
Q

Opioid agonists Hepatic metabolism Conjugation with sulfuric acid

A

In cats Morphine–> Morphine-3-Sulphate

55
Q

Opioid agonists Non-hepatic metabolism

A

Remifentanil Tissue (muscle, intestine) and plasma esterases

56
Q

Opioid agonists Elimination

A

Mainly as metabolites Some as free drug Mainly renal (80%) some fecal (20%) Enterohepatic recirculation (ex etorphine)

57
Q

Which Opioid agonists goes through enterohepatic recirculation?

A

Etorphine

58
Q

Opioid agonists Treatment Uses

A

Analgesia Preanesthetic Neuroleptanalgesia Antitussive Emesis Antidiarrheal

59
Q

Opioid agonists Analgesia

A

Morphine is prototype Before, during, after surgery Spinal analgesia Colic in horses (butorphanol infusion)

60
Q

What Opioid agonist is used for treatment of colic in horses?

A

Butorphanol infusion

61
Q

Opioid agonists Neuroleptanalgesia Drugs used

A

Combo of sedative & opioid Phenothiazine, benzodiazepine, alpha-2-agonist

62
Q

Opioid agonists Neuroleptanalgesia Effect

A

Synergistic effect, deep sedation, borders general anesthesia

63
Q

Opioid agonists Antitussive

A

Butorphanol (approved), hydrocodone, codeine, tramadol

64
Q

What effect do butorphanol, hydrocodone, codeine and tramadol share?

A

Antitussive. Anti-coughing

65
Q

Opioid agonists Emesis

A

Morphine IV in dogs Apomorphine (conjunctival mucosa)

66
Q

Opioid agonists Antidiarrheal

A

Loperamide Diphenoxylate

67
Q

Opioid agonists Loperamide

A

“Immodium” -Does not cross BBB -Caution with MDR-1 mutants

68
Q

Opioid agonists Diphenoxylate

A

Tincture of opium (paregoric)

69
Q

Opioid agonists Caution with these conditions

A

Epilepsy Tetanus Strychnine poisoning Head injury (could increase ICP) Severe cardiovascular or respiratory condition **Ceiling effect**

70
Q

Opioid agonists Reason for caution when have severe cardiovascular or respiratory condition

A

Potential depression of cough reflex Changes in myocardial blood flow Chest injury? Balance pain vs. respiratory suppression

71
Q

Opioid agonists As pain meds

A

Cause of pain should always be diagnosed & treated

72
Q

Opioid agonists Tolerance & dependence

A

Less of an issue in veterinary patients

73
Q

Opioid agonists Antagonist use

A

Use to revert toxic effects

74
Q

Opioid agonists Comments/Cautions

A

May need O2 supplement Vets can be killed by potent opioids! (etorphine, carfentanil)

75
Q

Opioid agonists Interactions

A

Sedatives NSAIDS MAO inhibitors Tricyclic antidepressants Serotonin re-uptake inhibitors

76
Q

Opioid agonists Interactions Sedatives

A

Synergy to induce neuroleptanalgesia

77
Q

Opioid agonists Interactions w/NSAIDS

A

Ex- Aspirin, acetaminophen, ibuprofen -“dose sparing” effect

78
Q

Opioid agonists Interactions w/MAO inhibitors

A

Ex- Selegiline, amitraz -Hallucinations in people, serotonin syndrome with tramadol

79
Q

Selegiline & amitraz are examples of ___?

A

MAO inhibitors

80
Q

Aspirin, acetominophen, ibuprofen are examples of ___?

A

NSAIDS

81
Q

Opioid agonists Interactions w/ Tricyclic antidepressants

A

Ex. Amitriptyline Additive CNS depression

82
Q

Amitriptyline is an example of what type of drug?

A

Tricyclic antidepressant

83
Q

Opioid agonists Interactions with serotonin re-uptake inhibitors

A

Ex. Fluoxetine Serotonin syndrome with pentazocine, tramadol

84
Q

Fluoxetine is an example of what type of drug?

A

Serotonin re-uptake inhibitor

85
Q

What opioid agonists does fluoxetine react with to cause serotonin syndrome?

A

Pentazocine Tramadol

86
Q

Describe serotonin syndrome?

A

Excitation Sweating Rigidity Coma Seizures

87
Q

Opioid agonists Classifications - u agonist

A

Morphine Natural opioid Prototypical analgesic Analgesia Preanesthetic Histamine release

88
Q

U agonist analgesia time chart

A

Analgesia onset 15 mins Peak 30-45min Duration up to 4h (IM) or 24h (IT)

89
Q

U agonist - Morphine histamine release

A

After IV injection (dogs) Give slowly or another route

90
Q

u agonist - Hydrocodone

A

Semisynthetic opioid 6x more potent than morphine Sometimes orally to dogs Antitussive (mainly) Analgesic (sometimes)

91
Q

Hydrocodone human formulation

A

May contain other drugs -Homotropine -Be aware with human pharmacies

92
Q

U agonist- Hydromorphine

A

Semisynthetic opioid Greater lipid solubility Greater potency (8x) than morphine Analgesia Preanesthetic Less histamine release than morphine Less expensive than oxymorphone

93
Q

Hydrocodone orally to dogs

A

F= 34-44% Demethylated to hydromorphone

94
Q

Hydromorphone Analgesia timetable

A

Onset 5-10min Peak 20-30min Duration similar to morphine 2hr IV 4h IM

95
Q

U agonist - Oxymorphone

A

Semisynthetic 10x potency of morphine More lipophilic Analgesic Preanesthetic

96
Q

Oxymorphone Species uses:

A

FDA approved for dogs & cats Off-label in horses & pigs

97
Q

Oxymorphone compared to hydromorphone

A

Less emesis & histamine release than hydromorphone

98
Q

U agonist - Methadone

A

Synthetic opioid NMDA receptor antagonist Serotonin & NE reuptake inhibition Analgesia & potency like morphine

99
Q

Methadone - species uses

A

Dogs Cats Horses (excitement) More in Europe than N. Am

100
Q

U agonist- Fentanyl

A

Synthetic 100x more lipophilic and potent analgesia than morphine Use before, during, after anesthesia

101
Q

Fentanyl analgesia time

A

Onset 1 min Peak 2.5-10min Duration 30 min

102
Q

Fentanyl - Approved species

A

Approved in dogs in combination with droperidol

103
Q

Fentanyl- Administration

A

IV CRI (after loading IV dose) Transdermal

104
Q

Fentanyl transdermal patches

A

Lag time to therapeutic effect (12-24 hrs- dogs, 6-12hr cats) Therapeutic concentrations for 72hr-dogs, 120hr-cats Therapeutic concentrations for 2-12hr after patche removal (accumulation in skin)

105
Q

Fentanyl transdermal patch DONT CUT IT

A

Different sizes with different doses Cover part of patch if necessary

106
Q

How should a Fentanyl patch be disposed of?

A

**Patch must be flushed for disposal**

107
Q

How can dysphoria from the Fentanyl patch be controlled?

A

Acepromazine

108
Q

U agonist - Carfentanil

A

Synthetic 10,000x more potent analgesic than morphine -Moose, elk, deer, zoo animals

109
Q

Carfentanil antagonists

A

Naloxene Naltrexone Diprenorphine (M50/50)

110
Q

U agonist - Etorphine M99!!

A

Synthetic U, K, gamma agonist! ~4000x more potent than morphine -Zoo & wildlife -Dart immobilization (IM)

111
Q

Etorphine antagonists

A

Naloxone Diprenorphine (M50/50)

112
Q

Partial agonist activity

A

*Picture*

113
Q

U agonist activity

A

*Picture*

114
Q

Partial agonist - Buprenorphine

A

Semisynthetic u & K antagonist 25x more potent than morphine Neuroleptanalgesia

115
Q

Buprenorphine analgesic time chart

A

Slow onset 45 min Long duration 8hr (4hr, dog) Slow diffustion in and out of CNS Ceiling effect

116
Q

What drugs help buprenorphine cause neuroleptanalgesia

A

Acepromazine Xylazine

117
Q

What is needed to reverse respiratory depression from Buprenorphine?

A

High dose naloxone (or even doxapram)

118
Q

Agonist- antagonist activity

A

*Picture*

119
Q

Agonist/antagonist- Butorphanol

A

Synthetic K agonist Synthetic u agonist/antagonist 1-7x potency of morphine IV, IM, SC, PO

120
Q

How can Butorphanol be administered?

A

IV IM SC PO

121
Q

Butorphanol analgesic timechart

A

3hr cat 90 min dogs 30 min horse Visceral not somatic pain Ceiling effect

122
Q

Pure antagonists

A

Naloxone Naltrexone/ Diprenorphine (M50/50) Methylnaltrexone (human med)

123
Q

What are full/pure antagonists used for?

A

Reverse effects of opioids -Overdose -Opioid-induced respiratory depression

124
Q

What type of drugs are naloxene, naltrexone/diprenorphine, and methylnaltrexone?

A

Full/Pure opioid antagonists

125
Q

Full antagonist - Naloxone

A

Competitive receptor antagonist (u>K = gamma) Approved in dogs Reverse opioid effects Reverse hypovolemic shock in dogs

126
Q

Naloxone administration

A

IV IM SC

127
Q

Naloxene reversal of canine hypovolemic shock

A

B-endorphins reduce sympathetic vasoconstrictor response, directly induce venodilation

128
Q

Naloxene timechart

A

Rapid onset (few mins) short duration (1-2hr)

129
Q

Full antagonist - Natrexone

A

Competitive receptor antagonist (u=K=gamma) Reversal of carfentanil in moose & elk 1/4 of dose IV and remaining 3/4 SC

130
Q

Full antagonist Diprenorphine (M50/50)

A

Competitive receptor antagonist (u=k=gamma) Reversal of etorphine in wild & exotics Also reverse carfentanil

131
Q

Full antagonist - Methylnaltrexone

A

“Relistor” Human med Doesnt cross BBB Reverse peripheral effects (constipation) without reversing analgesic effects

132
Q

Other Opioids

A

Tramadol Apomorphine

133
Q

Tramadol

A

Multimodal, central-acting analgesic Oral administration Treat moderate pain or cough in dogs/cats May lower seizure treshold in epileptic patients

134
Q

Tramadol as analgesic

A

Multimodal, central-acting Weak u-opioid agonist Serotonin reuptake inhibitor NE reuptake inhibitor M1 receptor antagonist

135
Q

Apomorphine

A

Originally, morphine decomposition product Now completely synthesized Vomiting in dogs Poisoning treatment

136
Q

Apomorphine as vomiting inducer

A

Low doses and concentrations D2-like family receptor agaonist in CRTZ and vomiting center SC, onto conjunctiva, IV, IM High doses- antiemetic effects (activate central u-opioid receptors?)