Exam 2: Lecture 12: Adjunct drugs and reactions Flashcards
What are adjunct drugs to anesthesia and
analgesia?
Drugs that may or may not be common for clinical use, but
play a supportive role by the benefit that they provide the
patient
Define Balanced anesthesia
simultaneous use of multiple drugs &
techniques to produce anesthesia
Define Multimodal analgesia
using 2 or more different drugs
or techniques to manage pain
Which drug is a neurokinin-1 receptor
antagonist, often used for motion sickness
Maropitant AKA Cerenia
Maropitant (trade name: Cerenia) is a neurokinin-1 receptor
antagonist, often used for motion sickness. Benefits in perioperative
period include:
- Reduced incidence of vomiting from certain premedication drugs
- Improvement in recovery quality and a faster return to feeding
- Potential MAC lowering effects (when administered as a CRI)
What is an important clinical note for Maropitant
mportant clinical note – does not prevent gastroesophageal reflux (GER)
Which drug is FDA approved for use in dogs for motion sickness and acute vomiting
- Common side effects of higher doses of _____ is excessive drooling
Maropitant AKA cerenia
Is vomiting passive or active?
active
Is regurgitation passive or active?
Passive
Does the following describe Vomiting or regurgitation?
- Forceful ejection of stomach and upper intestinal contents
- Can contain yellow bile or partially digested dog food
- Usually smells sour and involves heaving
vomiting
Does the following describe Vomiting or regurgitation?
- Mild ejection of undigested food from the esophagus
- Does not involve abdominal heaving
- Tends to happen just after eating
Regurgitation
Which drug is a 5HT3 receptor antagonist?
Ondansetron
Which drug is antimetric that works at the level of the vomiting center in the brain, particullary useful for prevention of vomiting due to chemotherapy drugs or from anesthetic drugs that induce vomiting
Ondansetron
- Less effective than maropitant in prevention of vomiting, but
oral administration can reduce incidence of nausea.
How is Ondansetron available?
Available in tablet form, oral solution and injectable solution
Which drug Blocks dopamine D2 receptors in chemoreceptor trigger
zone and also blocks serotonin receptors to contribute to
antiemetic effects
Metoclopramide
Which drug has prokinetic effects reduce amount of gastric fluid (via
increasing the rate of gastric emptying) and increase lower
esophageal sphincter tone
Metoclopramide
What drug fits the following description:
❖May increase CNS depressant effects of anesthetic
drugs
❖Do NOT give if GI obstruction suspected, history of
seizures or pheochromocytoma is present
Metoclopramide
Which drug class can be Given to decrease acid production in the stomach (H2 antagonists
such as famotidine or ranitidine)
Histamine receptor antagonists
Which drug is commonly given prior to mast cell tumor removal
to competitively counter the effects of histamine (H1 antagonist)
Diphenhydramine
An eight year olf female spayed boston terrier is presented with a solitary well circumscribed mass two cm in diameter on the left hip area. The owner reports that the mass occasionally appears inflamed and the dog has a history of allergies
- A fine need aspirate of the mass stained with Diff Quick is also shown
- What pre-operative treatment is indicated?
H1 histamine receptor antagonist - corticosteroids
What drug Decreases gastric acid production by
irreversibly blocking H+/K+ ATPase
Proton pump inhibitor
Omeprazole and pantoprazole most
commonly used. Long-acting drugs
ACVIM consensus statement: judicious use of
acid suppressants warranted for long-term
administration. Routine use for treatment of
acute, nonerosive gastritis not
recommended.
Prefer to give _______ postoperatively in case hypovolemia or
hypotension occurs during anesthetic period, leading to decreased
renal blood flow. But many practitioners give them before surgery.
NSAID’s
What is the MAC spraing effect for Carprofen?
decreased MAC of Sevo to 2.10% in dogs
What is the MAC sparing effect of meloxicam?
decreased MAC of Sevo to 2.06% in dogs
NEVER give _______ concurrently with NSAIDs
Glucocorticoids
_______ is Used for anti-inflammatory, analgesic,
immunosuppressive, and for physiologic
support of Addisonian patients
Glucocorticoids
give Cefazolin _______ IV
Slowly - over 5 minutes
give Unasyn (Ampicillin/Sulbactam) _______ IV
slowely - over 15-30 minutes
You can give gentamicin if……
Given IV
- administer slowely
give K-pin ______
slowly through IV
T/F: You can give PPG both IV and IM
FALSE!!!!!
never give IV
Which antibiotic is used in food animals
- Genatmicin
- K - pen
- PPG
- Naxcel
Naxcel
How do you administer Aminocaproic acid?
Oral and injectable formulations available. Give slowly IV
(over 30 minutes) after diluting in saline to prevent CV
effects.
Which drug is an Anti-fibrinolytic agent
Aminocaproic acid
Define anti-fibrinolytic agent Aminocaproic acid
– Can be given to Greyhounds to decrease postoperative
bleeding by enhancing clot formation and increasing clot
strength (2012 studies by Marin et al)
– Greyhounds typically have higher than normal rates of
bleeding 24-48hrs post op → see bruising around surgical
site
Which Hormone given to temporarily increase von
Willebrand factor in dogs with a deficiency prior to
surgery. Promotes vWf secretion from endothelium
storage sites.
Desmopressin
_________ is a synthetic replacement for
vasopressin → hormone that reduces urine
production
Desmopressin
How is desmopressin typically available?
Available as a nasal spray typically
- Expensive! Usually have the owner purchase at
human pharmacy.
Which drug is a Peripherally acting muscle relaxant
– Works on skeletal muscle, but cardiac depression reported at higher
doses
Dantrolene
MOA of Dantrolene
ryanodine receptor antagonism → reducing Ca2+
release from the SR into the cytoplasm
Which drug is used for the treatment and prevention of malignant
hyperthermia and exertional rhabdomyolysis
Dantrolene
– Pigs, humans, dogs, horses
– Injectable solution and oral capsules available
– Dose is species dependent (dogs, cats, pigs: 1-3 mg/kg IV for
treatment and 5 mg/kg PO once daily for prophylaxis)
T/F: Doxapram is a CNS stimulant
true
Which drug cases arousal from sedation/anesthesia (this use is
controversial), stimulation of respiration in neonates, and
assessment of laryngeal function (dogs & horses)
Doxapram
What is the MOA for Doxapram
likely due to both central and peripheral effects →
increased activity of the respiratory nuclei of the medulla. But
full understanding of MOA is not clear.
– Significant increase in minute ventilation through an increase in RR
and tidal volume
Which drug can cause Increased dosages can lead to convulsions due to cortical
stimulation. Dosages cause differing effects among species.
– Avoid in epileptic patients
Doxapram
Which drug is Central acting muscle relaxant with sedative properties
– Unknown MOA, but likely works both in the brain and spinal cord
Guaifenesin - GG
Which drug can be Co-administered with IV anesthetics (e.g. ketamine) in
horses and ruminants
– To induce anesthesia
– To maintain anesthesia
Guaifenesin - GG
Which drug fits these characteristics
› No known analgesic properties
› Wide therapeutic margin, with mild cardiorespiratory
effects when given at therapeutic doses
› Commonly prepared in 5-15% solution with 0.9% saline or
5% dextrose solution.
– Perivascular injection may cause necrosis
Guaifenesin - GG
_______ is an amide local anesthetic drug used to provide
locoregional analgesia and also used systemically to treat
ventricular arrhythmias.
Lidocaine
Which drug shows Body of evidence in many species (humans, dogs, horses) that
shows MAC sparing, anti-inflammatory, and analgesic effects.
Also has prokinetic effects on the GI tract by stimulating
intestinal motility
Lidocaine
T/F: Lidocaine is typically not used in cats
true!!!
Not typically used in cats as a CRI due to potential for toxicity!
Lidocaine us used in equine for the treatment of?
– Ileus → stimulates intestinal muscle contraction (in vitro) + analgesia
– Impactions
– Duodenitis-jejunitis
– Inflammation → preserves microvascular integrity, prevents neutrophil migration, and inhibits cytokine production
– Laminitis
– Post-operative pain
Often given for 1 to 3 days, but must be carefully monitored
What are the signs of lidocaine toxicity?
– Muscle fasciculations, weakness, recumbency
– Discontinue lidocaine immediately → signs should quickly disappear
Which drug is a NMDA receptor antagonist given as an intraoperative CRI
binds at the CNS receptors and prevents “wind up”
Ketamine
Which drug is Best used to manage neuropathic types of pain → especially if
the pain is chronic and the patient has not responded well to
other analgesic options
Ketamine
Always combine _______ with an opioid and/or lidocaine infusion
Ketamine
Provide some examples of opioids that can be used as a CRI?
– Fentanyl
– Remifentanil
– Morphine
– Hydromorphone
– Butorphanol
– Buprenorphine
T/F: opioids are Typically a loading dose is given first, followed by CRI
True
Why give a loading dose?
Get the drug into the theraputic windown and stay there rapidly
- Best way to prevent pain
What is a MLK CRI
Morphine - Lidocaine - Ketamine (MLK) CRI
- found morphine, lidocaine, ketamine, and MLK
significantly lowered isoflurane MAC by 48, 29, 25, and 45%,
respectively. Not associated with adverse CV effects. - found infusion of dexmedetomidine, MLK, and
DMLK decreased the MAC of isoflurane from baseline by 30%, 55%, and
90%, respectively.
What should you add to an MLK bag after you add the drugs?
Label
Date
Initials
Define Drug Interactions
› Some are harmful, some are beneficial
› Can occur in vitro (in syringe or vial) vs. in vivo (in patient)
› In vitro (pharmaceutical interactions) → drug precipitate, toxic
product, or inactivate one of the drugs
– Acid-base interactions
– Chemical incompatibilities
› In vivo → PK and PD can be affected
– Absorption
– ABCB1
– Hepatic clearance
– Drug protein binding
What is a MDR1 gene mutation (AKA ABCB 1 mutation)
Some herding-breed dogs have a single mutation in a gene
coding for a protein (P-glycoprotein) that drastically affects
absorption, distribution, metabolism and excretion of drugs
____________ is an important part of the blood-brain barrier
→ protects body from toxic accumulations of substances
P-glycoprotein
Anesthesia drugs affected by MDR1 gene mutations are?
- Butorphanol
- acepromazine
MDR1 gene mutation
- why does this matter???
– Dog with this mutation may have more serious side effects,
such as CNS and/or respiratory depression, from certain
anesthetic drugs.
– Recovery may take longer and patient may still appear
sedate long after the drugs should have normally worn off.
– Generally recommend reducing normal dose by 25-50% in
dogs that are homozygous for the mutation.
___________ – precipitation will occur with aqueous solutions
and significant absorption into soft plastic (i.e. fluid bags or
tubing) within 24 hours. Also incompatible with heparin flush
Diazepam
Epinephrine, dobutamine, and dopamine are incompatible
with _______ solutions
Alkaline
Which drug precipitates with aqueous solutions
Phenylbutazone
Which drugs do not mix with solutions that contain
calcium (ex. LRS) because precipitation may occur
Sodium bicarbonate
Define Addition
simple additivity of fractional doses of two or more
drugs
Define synergism
response to fractional doses is greater than the
response to the sum of the fractional doses
Define Potentiation
enhancement of action of one drug by a second
drug that has no detectable action of its own
Define Antagonism
opposing action of one drug toward another.
Can be competitive (drugs compete for same receptor site) or
noncompetitive ( drugs act via different receptors)
What is defined as when you can give lower amount of each drug
Synergism
What is defined as the higher amounts of each drug because they are antagonizing each other
Antagonism
What is an Isobologram
Shows the connection when you give two drugs together and how they effect one another
