Pharmacology II: Sedatives & Induction Agents Flashcards
Phenothiazine
Drug: Acepromazine
Action: (2)
Possible side-effects: (6)
- Action:
- Tranquilizer –> sedation, antiemetic
- No analgesia! - Side effects:
- Hypotension/hypothermia
- Prominent nictitans membrane
- Prolonged sedation (6-8hrs)
- Penile prolapse
- Idiosyncratic aggression
- Increased risk for seizures historically reported (not confirm w/follow up studies)
Common sedatives used before surgery (4)
- Phenothiazines
- Benzodiazepines
- Alpha2 agonists
- Opiates
Phenothiazines should not be given to patients… (7)
With…
1. Epilepsy or Hx of seizures
2. Liver disease
3. Heart disease
Who are…
4. Geriatric or pediatric
5. In dehydration/hypotension/shock
6. Breeding stallions (penile prolapse)
7. Receiving eye exams
Benzodiazepines
The drugs (4)
Action (3)
- Drugs:
- Diazepam (valium)
- Midazolam (versed)
- Alprazolam (xanax)
- Zolazepam (part of telazol) - Action:
- Tranquilizer
- Muscle relaxant
- Antiseizure by enhancing GABA effects in brain
Benzodiazepines
Advantages: (4)
Possible side effects: (4)
- Advantages:
- Reversal agent (flumazenil)
- Min depression of resp or cardio systems
- Short-acting (20min)
- Can be combined with ketamine or tiletamine - Side effects:
- Appetite stim
- Liver failure if given orally to felines
- Hypotension if IV inj too rapid
- Diazepam is painful & not well absorbed if given IM
Alpha2 Agonistis
The drugs: (3)
Actions: (2)
- Drugs:
- Xylazine (rompun)
- Dexmedetomidine (dexdomitor)
- Medetromidine (domitor) - Action:
- Sedative that decreases norepinephrine release (inhibits sympathetic nerve system)
- Analgesia (shorter than sedation)
Alpha2 Agonist
1. Possible side effects: (5)
2. Reversal agent: (2)
- Side effects:
- Profound bradycardia; AV heart block
- Maintains BP thru vasoconstriction
- Vomiting (esp cats)
- Risk of bloat in deep chested dogs
- Cattle very sensitive - Reversal:
- Yohimbine
- Atipamezole
T/F: Use of Alpha2 Agonist is mostly limited to healthy, young dogs & horses being closely monitored
True
Opioids
The drugs: (7+)
Action: (1)
- Drugs:
- Butorphanol
- Morphine
- Buprenorphine
- Hydromorphone
- Oxymorphone
- Hydrocodone
- Codeine
- Etc - Action
- Sedation & analgesia by binding to opiate receptors of CNS
Opioids
Possible side effects: (5)
Reversal agent: (1)
- Side effects:
- Resp depression
- Excitement if given rapidly IV
- Excitement if used alone in cats or horses
- Vomiting
- Impaired thermoregulation - Reversal
- Naloxone (narcan)
Induction Agents are drugs used to…
They are sometimes used alone for…
- Facilitate smooth & rapid transition from consciousness to unconsciousness
- Short anesthetic procedures
Injectable vs Mask Down
FYI: Quiz question!!
Induction agents (5)
- Alfaxalone
- Propofol
- Barbiturates
- Dissociative agents (ex keta)
- Guaifenesin
Alfaxalone (Alfaxan)
Actions: (3)
Advantages: (3)
- Actions:
- Neuroactive steroid: anesthesia by GABA enhancement
- IV inj should be administered slowly over 60sec
- Short acting anesthetic for both procedures & induction (IV & IM) - Advantages:
- Metabolized rapidly by liver
- Cardiovascular sparing: heart safe
- Safe to use as a continuous rate infusion
Alfaxalone
Disadvantages: (3)
Controlled substance or not?
- Disadvantages:
- Apnea
- Hyperexcitability on recovery (minimal)
- Not analgesic - Controlled substance
- Schedule IV drug
Propofol
Actions: (3)
Advantages: (3)
- Actions:
- Phenolic compound unrelated to any other general anesthetics
- Not water soluble: soybean oil, egg lecithin, & glycerol
- IV use only!! - Advantages:
- Good muscle relaxation
- Quality of anesthesia good
- Quality of recovery is excellent
Propofol
Disadvantages: (5)
- Disadvantages:
- No analgesia
- If given rapidly, can cause apnea: pre oxygenate!!
- Contains no preservative (except propofol28 - 28day it’ll last)
- Only licensed for dogs
- Use with caution in cats
Barbiturates
Drugs: (3)
Action: (1)
Advantages: (3)
- Drugs
- Thiopental (ultra-short)
- Pentobarital (short)
- Phenobarbital (long) - Action: Unknown
- Advantages
- Least expensive inj anesthetics
- No specialized equipment for administration
- Rapid onset of action, provide predictable response, & rapid recovery following single dose administration.
Barbiturates precautions when using ultra-short acting:
The drug must be given ___ because of its high alkaline pH and perivascular inj will cause tissue ___.
There is a small margin of safety between ___ and ___ dose, especially in debilitated patients.
___ and profound ___ depression following IV bolus inj often occur.
- IV
- Only give with secured IV access - Necrosis
- Effective
- Lethal
- Apnea
- Respiratory depression
Barbiturates should not be used in ___ & ___ patients.
They are all ___ substances.
- Sighthounds
- Hypoproteinemic animals
- Redistribution in brain vs fat stores
- Poor liver metabolism - Controlled
Dissociative agents (2)
Ketamine
Tiletamine (telazol)
Ketamine & Tiletamine
Action: (5)
In dogs, what is it often combined with? Horses?
- Action:
- N-methyl-D-aspartate (NMDA) antagonist
- Anesthesia
- Amnesia
- Catalepsy
- Analgesia - Combined with
- Dogs: diazepam or midazolam
- Horses: Xylazine or detomidine
Ketamine & Tiletamine
Advantages: (3)
Disadvantages: (5)
- Advantages
- Tend to maintain normotension
- Analgesia achieved
- Amnesia - Disadvantages
- Eyes open (w/nystagmus)
- Hallucination or delirium w/o sedative used WITH it
- Hypo-/hyperthermia
- Can be hypertensive
- Sting IM inj
Guaifenesin is an intravenous central-acting ___ that potentiates anesthetic agents, commonly used in ___ animals.
It is also used as an ___ in small animals & humans.
This should be given through an ___ ___ because of risk of perivascular tissue ___.
- Relaxant
- Large
- Expectorant
- IV catheter
- Necrosis
