CNS Drugs

  1. Phenothiazines are considered a class of what?
  2. What 2 drugs are classified as phenothiazines?
    • Acepromazine (PromAce®)
    • Chlorpromazine (Thorazine®)
  3. What is the MOA of phenothiazines?  What are they categorized as?
    • Block the post-synaptic dopamine receptors in the CNS
    • Alpha-1 agonists
  4. What effects do phenothiazines have on the body?
    • Sedation
    • Anti-emetic
    • Antihistamine
    • Anti-arrythmic
  5. What are the uses of phenothiazines?
    • Pre-anesthetic
    • Itch relief
    • Anti-emetic
  6. Do phenothiazines have analgesic effects?
  7. What are side effects involved in the use of phenothiazines?
    • Penile prolapse
    • Hypotension
    • Decreased seizure threshold
    • Paradoxical excitation/aggression
  8. What precautions/contraindications are associated w/ phenothiazines?
    • Liver dysfunction
    • Cardiac disease
    • Geriatrics
    • Giant breeds, boxers, greyhounds are more sensitive
    • Cats and terriers more resistant
  9. Why should caution be taken when using phenothiazines in a patient with liver dysfunction?
    Phenothiazines are metabolized by the liver
  10. What forms of administration are used for PromAce®?
    SQ, IM, IV, Tabs
  11. Injectable routes for Acepromazine should not exceed this total amount.
    3 mg
  12. What phenothiazine is used for it's anti-emetic effects?
    Chlorpromazine (Thorazine®)
  13. What is the difference between a sedative and a tranquilizer?
    A sedative reduces consciousness, while a tranquilizer reduces anxiety
  14. Is PromAce® a sedative or a tranquilizer?
  15. Are phenothiazines controlled substances?
  16. Are benzondiazepines controlled substances?
  17. What is the mode of action of a benzodiazepine?
    Depression of the limbic, thalamic and hypothalamic levels of CNS
  18. What effects fo benzodiazepines have on the body?
    • Anti-anxiety/calming
    • Skeletal muscle relaxation
    • Anti-convulsant
    • Few cardiovascular effects
  19. What do benzodiazepines not provide?
  20. What are some uses of benzodiazepines?
    • Restraint/sedation
    • Anti-anxiety
    • Anti-convulsant
    • Muscle relaxation
    • Appetite stimulation (cats)
  21. When would benzodiazepines not be used due to contraindications?
    • Pregnant animals due to cross placental ability
    • Hepatic/renal disease
    • Debilitated/geriatric patients
    • Coma
  22. How should benzodiazepines be injected when administering IV?  Why?
    Slowly because they may cause pain and bradycardia/hypotension
  23. What is the reversal agent for benzodiazepines?
  24. What are some side effects of benzodiazepine use?
    • Muscle fasciculations, weakness and ataxia in horses @ doses for sedation
    • Liver failure in cats receiving generic Diazepam® for several days
    • Excitation of CNS in dogs when used alone
  25. What is the trade name for Valium?
  26. What is Valium often used in combination with?
  27. Name a few characteristics about Diazepam®
    • Absorbable in plastic
    • Light sensitive
    • Not water soluble
    • Not compatible with most other agents
  28. What are the routes of admin. for Valium?  What route is avoided due to poor absorption?
    • IV, rectally, Tab, gel
    • IM
  29. What is the trade name for Midazolam?
  30. Name 3 characteristics of Midazolam that are different than Diazepam®.
    • IM absorbable
    • Mixes with other agents
    • Less tissue irritation
  31. What are the routes of admin. for Versed?
  32. Are Alpha-2 agonists controlled substances?
  33. What is the MOA for Alpha-2 agonists?
    • Stimulation of the Alpha-2 receptors in CNS to decrease norepinephrine levels
    • Decrease in heart & blood vessel activity
  34. Name effects of Alpha-2 agonists.
    • Sedation
    • Analgesia
    • Muscle relaxation
    • Emesis (cat)
    • Thermoregulatory depression
    • Bradycardia
    • Vasoconstriction
  35. What are Alpha-2 agonist agents used for?
    • Sedation
    • PA
    • Analgesia
    • Emesis
  36. What age group are Alpha-2 agonists best used in?
    Young, healthy patients
  37. When should extreme caution be taken when using an Alpha-2 agonist?
    • Cardiac dz
    • Hypotension/shock
    • Liver/renal dz
    • Seizure disorders
    • Debilitated
  38. When is the use of Alpha-2 agonists contraindicated?
    Animals receiving epinephrine or that have active heart arrhythmia
  39. Alpha-2 agonists can cause premature ________, and _____ _________ or ______ in cattle
    Labor; rumen stasis; bloat
  40. The dose of Aplpha-2 agonists is reduced how much in cattle?  Why?
    10% because cattle are very sensitive to Alpha-2 agonists and they can cause rumen stasis and bloat
  41. What are the adverse effects of Alpha-2 agonists? (8)
    • Muscle tremors
    • Bradycardia
    • Resp depression
    • Mvmnt response to loud noise
    • Polyuria (cat)
    • Bloat (dogs)
    • Sweating (horses)
    • Hypotensive effects w/ other trainquilizers
  42. What are the 3 Alpha-2 agonists talked about in class?  What are their trade names and reversals?
    • Xylazine (Rompun®, AnaSed®, Gemini®): Yohimbine (Yobine®) for sm anml, Tolazoline (Tolazine®) for horses
    • Dexmedetomidine (Dexdomitor®): Atipamezole (Antisedan®)
    • Detomidine (Dormosedan®): Tolazine®, Antisedan®
  43. What units are Dexmedetomidine doses measured in?
    BSA (mcg/m3)
  44. How can Dexdomitor® be adminstered?
  45. Dexmedetomidine is approved for use in dogs over ____ weeks of age and cats over _____ weeks of age.
    16; 12
  46. What are effects of Dexmedetomidine?
    • Bradycardia
    • Decreased seizure threshold
    • Hypertension
  47. What should Dexmedetomidine never be used with?  Why?
    Atropine because it causes severe arrhythmia's
  48. Why should Atipamezole not be given IV?
    Vasoconstriction is reversed before bradycardia which can cause cardiovascular collapse
  49. What is Dormosedan® used for?
    Sedation and analgesia in horses
  50. Barbiturates are controlled substances which are categorized into 4 classes based upon their action time.  What are they?
    • Long-acting (8-12 hrs)
    • Intermediate-acting
    • Short-acting (45 min - 2 hrs)
    • Ultra-short acting (5 - 30 min)
  51. What is the mode of action of barbiturates?
    Depression of the reticular activating system of the brain by inhibiting release of Ach & norepinephrine
  52. Barbiturates have a high lipid solubility.  What are the steps of absorption associated with barbiturates?
    • 1: goes to brain
    • 2: slowly redistributed to muscle and adipose tissue
    • 3: drug leaves brain
    • 4: drug slowly released from muscle and adipose
    • 5: metabolized in liver
  53. The _______ the lipid solubility of a barbiturate, the ________ tha amount redistributed to fat
    Higher; higher
  54. What are the effects of barbiturates?
    Cardiac, resp, and CNS depression
  55. When administered IV, barbiturates can commonly cause this.
    Transient apnea
  56. What are the uses of barbiturates?
    • Sedation
    • Anti-convulsants
    • Anesthetic induction
    • Euthanasia
  57. List the contraindications and precautions associated with barbiturates.
    • Resp depression pronounced in cats
    • Decreased dosages with hypoproteinemia b/c they are protein bound
    • Acidosis requires decreased doses b/c acidic pH has greater effects
    • Perivascular necrosis it administered extravascular
    • Caution w/ renal/hepatic compromise and hypotension
  58. What should barbiturates not be used in?
  59. How are barbiturates dosed?
    • To effect
    • Dose calculated but only administered until effects are seen
  60. Do barbiturates have an excitement phase?
  61. What are adverse effects of barbiturates?
    • Severe cariovascular, resp & CNS depression
    • Paradoxical CNS excitement
    • Death
  62. This drug is a DEA CIV, long-acting barbiturate.
  63. Phenobarbital is used for what?
    Long term anticonvulsant therapy
  64. How long does it take Phenobarbital to reach therapeutic levels in the blood stream?
    3 wks
  65. This barbiturate requires blood level monitoring due to its long term use due to the chance of liver enzyme elevation.
  66. What can be seen with Phenobarbital use?
    PU/PD & polyphagia
  67. What are the admin routes for phenobarbital?
    • Tab
    • IV
  68. Name the barbiturate that is an ultra-short acting DEA CIII drug.
    Thiopental (Pentothal®)
  69. What is Pentothal® used for?
    General anesthesia induction
  70. Should Pentothal® be used alone in horses?  Why?
    No b/c it causes excessive ataxia & excitement
  71. This drug is a DEA CII that is used to treat status epilepticus or for euthanasia.
  72. Name 4 euthanasia solutions.
    • Fatal Plus
    • Sleepaway
    • FP-3
    • Beuthanasia-D
  73. Pentobarbital is lowered to a CIII drug if one of these two drugs are added to it.
    • Lidocaine
    • Phenytoin
  74. Pentobarbital causes what w/ high doses?
    Severe depression of the medullary, resp & vasomotor centers
  75. What is the dose of Pentobarbital? When can it be doubled?
    • 1ml/10 lbs
    • Known cardiac patients
  76. Pentobarbital solutions are typically viscous.  What can be done to make administration easier?
    • Lg gauge catheters
    • Saline dilution
  77. How is Pentobarbital administered?
    • IV
    • IP - not ideal
    • IC - pocket pets for euthanasia
  78. What are the uses of dissociatives?
    • Anesthetic induction
    • Restraint
    • Anesthesia for short procedures
  79. What are the 2 dissociatives covered in class?
    • Ketamine
    • Tiletamine (Telazol®)
  80. What are the effects of dissociatives?
    • Exaggerated reflex responses
    • Marked light & sound sensitivity
    • Increased muscle tone
    • Fair M/S analgesia
    • Poor visceral analgesia
    • Tachycardia
    • Vasoconstriction
    • Apneustic resp
  81. What is the MOA for dissociatives?
    • Overstimulation of the CNS causes analgesia & anesthesia
    • Suppression of thalamic/cortical system
    • Activation of limbic system (memory & emotion)
  82. Are dissociatives controlled sunstances?
  83. Are barbiturates reversible?
  84. What are contraindications/precautions associated with dissociatives?
    • Rough recoveries
    • No blinking therefore eye lubricant is important
    • PLR cannot be monitored
    • No use in animals for consumption
    • Increase of IOP & intracranial pressure
    • No use in renal & liver compromise, as well as hypertension & heart dz
    • May induce seizures
  85. What are the adverse effects that may be seen with use of dissociatives?
    • Pain w/ IM inj
    • Increased salivation
    • Resp depression
    • Personality changes
    • Emesis
    • Vocalization
    • Erratic/prolonged recovery
    • Spastic, jerky movements
    • Seizures, muscle tremors
  86. Ketamine is a C _ drug commonly used with what 4 drugs?
    • III
    • Diazepam®, Rompun®, PromAce®, and Guaifenesin
  87. The Ket/Xylazine combo has been known to cause what?
    • Cardiac arrhythmias, pulmonary edema, resp depression in dogs
    • Cardiovascular collapse post-op in cats
    • Excellent analgesia, muscle relaxation and sedation in horses w/ min cardiovascular effects
  88. Ket/Val is mixed with ________ volumes in the same syringe and is administered _____ for anesthetic induction.
    Equal; IV
  89. Ket/Ace combo is given __ and is commonly mixed with a full 10ml bottle of ______ and 1ml of _____, with a max. dose of __ no matter what the weight.
    IM; Ketamine; Acepromazine; 1ml
  90. Telazol® is the trade name for what?
  91. What class drug is Tiletamine?
  92. Before administration, Telazol® must be _________ and is well absorbed ___, but can also be used ___.
    Reconstituted; IM; IV
  93. Tiletamine is used for _____________ and _____________
    Anesthetic induction; short minor procedures
  94. Opiods are ________ that are naturally derived or synthetically produced from the ____________________.  Thay are a DEA C_ drug.
    Narcotics; opium poppy alkaloid; II
  95. What is the MOA of opiods?
    Spinal cord and brain receptor reaction to opiods that are naturally stimulated by endorphins and enkephalins
  96. What are the 4 opiod receptors?  What do they contribute to?
    • Mu: analgesia, euphoria, physical dependence
    • Kappa: vocalization, hallucinations
    • Sigma: analgesia, sedation
    • Delta: modify Mu
  97. What are the effects of opioids?
    • Sedation (dog)
    • Anxiety/excitement w/ IV admin (cat)
    • Analgesia
    • Marked resp depression
  98. Name 3 uses of opioids
    • Analgesia
    • Antitussive
    • PA
  99. What is the reversal agent for opioids?
    Naloxone (Narcan®)
  100. Caution should be taken with opioids in animals with: (5)
    • Hypothyroidism
    • Renal dz
    • Addison's dz (hypoadrenocorticism)
    • Geriatrics/severely debilitated animals
    • Resp distress
    • Liver dz
  101. Opioids should not be used with the MOA inhibitors: (3)
    • Monoamine oxidase: Anipryl
    • Tricyclic antidepressants: Elavil (amitriptyline), Clomicalm (clomipramine)
  102. IV administration of opioids should be done __________ to prevent __________
    Slowly; bronchoconstriction
  103. What are adverse effects seen with opioid use?
    • Decreased resp & gastric motility
    • Addiction/dependence/tolerance
    • Facial swelling & hypotension (meperidine & morphine IV)
    • Increased urinary sphincter tone w/ urine retention
    • Excitation/mania w/ horse & cat
    • Hyperthermia in cat/horse
  104. What receptor does Morphine react with?
  105. Is Morphine natural?  What class drug is it?
    Yes; CII
  106. How can morphine be admin.?  How long does it stay active?
    • SQ, IM, IV, Tabs, Rectally
    • 2 - 4 hr duration
  107. What is the trade name for Oxymorphone?
  108. Whay class drud is Numorphan®?
  109. What opioid is 10x more potent than Morphine?  5x?
    Numorphan®; Hydromorphone
  110. Is Oxymorphone synthetic or natural?
  111. What is Torbugesic® used for?  What is it classified as?
    Antitussive; opioid
  112. What are two other names for Torbutrol®?
    Torbugesic®, Butorphanol
  113. Torbugesic come in an ____ form, while Torbutrol comes in a _____ form
    Inj; Tab
  114. This opioid is delivered at a CRI when given IV.
  115. What CIII opioid is 30x as potent as Morphine?  What is its trade name?  How is it given?
    • Buprenorphine (Buprenex®)
    • Buccal/sublingual
  116. When are neuroleptanalgesics used?
    When significant CNS depression is needed but not anesthesia
  117. An ________ and _______ combined form a neuroleptanalgesic.
    Opioid; tranquilizer
  118. Propofol is also known as _______ or ________.
    Propoflo®; Rapinovet®
  119. A rapid, smooth anesthetic induction through slow IV administration is caused by?
  120. Rapinovet® must be discarded after ___ hours due to it's short shelf life
  121. Propofol has no _______ effects and can cause significant ________ depression.
    Analgesic; resp
  122. Propofol is an induction agent that is relatively safe to use with what condition?
    Heart disease
  123. Why should Propofol be given w/ IV fluids?
    To prevent hypotension
  124. This drug is useful in high risk patients due to it's minimal cardiovascular and pulmonary effects.
  125. What action does Etomidate have on the brain?
    Maintains perfusion and decreases oxygen consumption
  126. Does Etomidate have a long onset of action?
  127. List adverse effects seen with Etomidate.
    • Pain upon inj
    • Vomiting
    • Nausea
    • Spontaneous muscle movements'RBC hemolysis w/ rapid induction
  128. This drug is a muscle relaxant often used in equine.
  129. What is Guaifenesin used for in small animals?
  130. What is the key ingredient in Guaifenesin?
  131. Dopram® stimulates the ________ of the brainstems to stimulate _______
    Medulla; breathing
  132. What is Doxapram used for?
    Increasing resp in animals with apnea or bradypnea
  133. What might Doxapram cause due to stimulation of the emotional and behavior centers of the brain?
    • Aggression
    • Muscle tremors
    • Hallucinations
  134. How is Dopram® given to neonates?
    Gtt under tongue
Card Set
CNS Drugs
Pre-anesthetics, side effects, effects, uses of PA's, contraindications, reversal agents, etc.