Pharm9

Question 1

Vomit

Answer 1

a protective mechanism designed to remove irritating substances from the GI tract

Question 2

Triggered by four types of stimuli:

Answer 2

1. Irritation of tissues innervated by vagus nerve
2. Stimulation of the chemoreceptor trigger zone
3. Stimulation of vestibular nerve
4. Stimulation of cerebral cortex

Question 3

Emesis

Answer 3

• Induction of vomiting is sometimes indicated in animals to remove toxic substances from GI tract
• Vomiting must be induced w/in 2 hrs. for liquids, w/in 4 hrs. for solids

Question 4

Do not induce vomiting if

Answer 4

o caustic substance was ingested
o gasoline or other petroleum products were ingested
o animal is unconscious or extremely depressed
o animal cannot normally vomit

Question 5

Drugs used to induce vomiting

Answer 5

• Two types available:
o Centrally acting emetics- stimulate dopamine receptors in the CNS
o Locally acting emetics- cause irritation of the GI tract

Question 6

Apomorphine

Answer 6

Stimulates dopamine in the CRTZ chemoreceptor trigger zone
IM, IV subconjuctivly
 centrally acting emetic
 rapid onset of effect
 given IV, IM, or subconjunctivally
 adverse effects include CNS depression, prolonged vomiting

Question 7

Xylazine

Answer 7

Works at the CRTZ
o	centrally acting emetic 
o	used mostly in cats
o	dose is lower than preanesthetic or sedation dose
o	effect can be reversed with yohimbine

Question 8

Locally acting Emetics

Answer 8

•	Hydrogen peroxide, warm concentrated salt water, mustard and water
o	locally acting emetic solutions 
o	may not work consistently 
o	H2O2= 1-2mls per kg
Max dose is 30mls

Question 9

Antiemetics

Answer 9

Antiemetics
• Drugs used to decrease or prevent vomiting
• Phenothiazine tranquilizers
o Examples: acepromazine, chlorpromazine, prochlorperazine

Question 10

General characteristics of Antiemetics

Answer 10

 block dopamine receptors in the CNS

 do not prevent vomiting caused by GI irritation

Question 11

Antihistamines

Answer 11

• Examples: diphenhydramine (Benadryl), dimenhydrinate (Dramamine)
o transmission of nerve impulses from vestibular nerve by blocking histamine receptors
o can produce a sedative effect and affect allergy testing

Question 12

Phenothiazine tranquilizers

Answer 12

o Examples: acepromazine, chlorpromazine, prochlorperazine
 block dopamine receptors in the CNS
 do not prevent vomiting caused by GI irritation- vagus nerve

Question 13

Anticholinergics

Answer 13

• Examples: aminopentamide (Centrine), isopropamide (Darbazine), atropine (short lasting)
o block nerve conduction through vagus nerve when there’s GI irritation (block acetylcholine receptors)
o may decrease GI secretions and GI motility
may be more effective

Question 14

Serotonin receptor antagonists

Answer 14

• Examples: ondansetron (Zofran) dolasetron (Anzemet)
o block nerve transmission through vagus nerve when there is GI irritation
o prevent simulation of CRTZ
o seldom used in animals

Question 15

Metoclopramide (Reglan)

Answer 15

o blocks dopamine receptors in the CNS in the CRTZ
o also acts locally in GI tract by:
 increasing lower esophageal muscle tone
 causing relaxation of pylorus
 increasing GI motility
o may cause sedation in dogs, excitement in cats

Question 16

Maropitant

Answer 16

o Newest, widely used antiemetic
o Prevents vomiting centrally and locally
o Labeled for used in dogs to prevent vomiting and motion sickness

Question 17

Anticonvulasants

Answer 17

Drugs used to prevent seizure activity

Question 18

Seizure

Answer 18

periods of altered brain function due to recurrent abnormal electrical impulses

Question 19

Epilepsy

Answer 19

recurrent seizures caused by a brain abnormality

Question 20

Convulsion

Answer 20

seizure characterized by spastic muscle movement

Question 21

Preictal phase

Answer 21

before seizure occurs

 pacing, panting, anxiety, apprehension

Question 22

Ictal phase

Answer 22

seizure occurs, lasts 1-2 minutes

Question 23

Postictal phase

Answer 23

after seizure subsides

Question 24

Partial Seizure

Answer 24

animal may exhibit spastic muscle contraction in a limb, facial muscles; animal may experience hallucinations, develop apparent blindness or behavioral abnormalities.
Not as common as grand Mal
Fly cacthing behavior, aggressive, restlessness pawing or biting at a limb for no reason

Question 25

Grand Mal Seizure

Answer 25

animal unconscious, exhibits spastic muscle contraction over the entire body; salivation, chewing, defecation, urination may occur, Fall to side, stiff, extension of the neck, repeated muscle contractions

Question 26

Status Epilepticus

Answer 26

a continual seizure

Question 27

Causes of seizures

Answer 27

* Idiopathic * Hypoxemia * Hypoglycemia * Hypocalcemia * Toxins * CNS infections * CNS tumors

Question 28

Phenobarbital

Answer 28

Phenobarbital Most popular anticonvulsant drug for long-term control of seizures The therapeutic dosage varies between individuals Therapeutic drug concentration monitoring necessary

Question 29

Phenobarbital Side effects

Answer 29

* sedation, incoordination, lethargy (common) | * liver disease and anemia (rare)

Question 30

Phenobarbital | General characteristics:

Answer 30

Distribution • Highly protein bound • Aspirin and sulfonamides displace it from proteins Biotransformation • Metabolized in the liver by the same enzymes that metabolize other veterinary drugs (e.g. glucocorticoids, phenylbutazone, estrogens, chloramphenicol)

Question 31

Potassium Bromide

Answer 31

• Commonly used in conjunction w/ phenobarbital to control seizures • Has a narrow therapeutic index GI irritation, sedation seen w/ toxicity • Eliminated by the kidney • Available as a powder that is mixed w/ dextrose or corn syrup for oral administration • Loading dose and therapeutic drug concentration monitoring necessary

Question 32

Diazepam

Answer 32

(Valium) • Drug of choice for emergency treatment of convulsing animals • Very effective when given intravenously • Drug is rapidly metabolized by the liver o Short duration o Poor effect if given orally to dogs • Also used as an appetite stimulant, for urine marking and anxiety in cats

Question 33

Loading dose

Answer 33

Higher amount of drug being given to the animal at the beginning of the treatment period. Establish higher drug concentration level in the circulating blood.

Question 34

Levetiracetam (Keppra)

Answer 34

(Keppra) | o Used on dogs (cats) when phenobarbital and/or potassium bromide aren’t controlling seizures adequatel

Question 35

Zonisamide

Answer 35

Used on dogs with refractory seizure activity

Question 36

Primidone

Answer 36

Drug is metabolized into phenobarbital by the liver

Question 37

Doxapram

Answer 37

• (Dopram) o Stimulates the respiratory center in the brainstem o Used to counteract apnea, slow breathing o Used w/ caution in animals prone to seizures - CNS Stimulants