Adverse Effects

Question 1

T/F: Penicillins relatively safe, but adverse effects are common, especially hypersensitivity reactions.

Answer 1

False - Adverse effects are rare

Question 2

What is a “procaine reaction”?

Answer 2

Procaine is a sodium channel blocker
Can lead to CNS excitement, convulsions, and seizures if given IV

Question 3

Aminoglycosides are _________

Answer 3

Nephrotoxic

Question 4

T/F: If we give a higher dose once daily of aminoglycosides, we are more likely to reach trough concentrations and lower risk of developing nephrotoxicity

Answer 4

True

Question 5

What factors might increase risk of nephrotoxicity with aminoglycosides?

Answer 5

Dehydration
Fever
Pre-existing renal disease
Neonates
Co-admin with other nephrotoxic drugs

Question 6

Discuss some mechanisms that we can limit nephrotoxicity (aside from dosing) when giving aminoglycosides

Answer 6

Administration of calcium is protective (competes with active transport on renal cells)

Fluid administration will decrease reabsorption

Question 7

In addition to being nephrotoxic, aminoglycosides are also _____

Answer 7

Ototoxicity - drug accumulates in tehe perilymph and the organ of corti

Increased risk with topical administration in the ear (avoid if eardrum ruptured)

Question 8

When should you NEVER use aminoglycosides?

Answer 8

In diseases of the NMJ (ex. Botulism)

Question 9

___________ toxicity is most commonly associated with fluoroquinolones. Who is most susceptible?

Answer 9

Cartilage toxicity

Puppies and foals

Question 10

Mechanism of fluoroquinolones resulting in cartilage toxicity

Answer 10

Chelation of magnesium in the cartilage leads to a decreased cell matrix interaction in the chondrocytes

Question 11

What factors increase risk of cartilage toxicity following fluoroquinolone administration?

Answer 11

Age - younger (immature cartilage/bone)

Weight - heavier

Activity level - more active

Number of doses - more doses

Question 12

What toxicity do fluoroquinolones cause in cats?

Answer 12

Ocular - retinal degeneration, blindness

Question 13

Ocular toxicity in cats is associated with enrofloxacin given at doses of ______mg/kg or higher

Answer 13

5

Question 14

Mechanism of ocular toxicity with fluoroquinolones

Answer 14

Changes in efflux pump allows accumulation of photoreactive FQs in feline retina

With exposure to light, ROS are produced leading to retinal degeneration and blindness

Question 15

Why is pradofloxacin not FDA approved for dogs in the US?

Answer 15

Caused bone marrow suppression

Question 16

Nephrotoxicity is associated with THIS specific drug

Answer 16

Oxytet - high doses or prolonged use of

Question 17

Doxycycline + Cat =

Answer 17

Esophageal stricture

Follow up with water or food to ensure that pill is completely swallowed

Question 18

IV Doxy + Horse =

Answer 18

Death

Question 19

Dental discoloration and inhibition of long bone growth are associated with _____. This is due to the __________.

Answer 19

Tetracyclines

Chelation of calcium

Question 20

Why are adverse effects seen commonly in dogs given potentiated sulfonamides?

Answer 20

Decreased ability for acetylation

Instead of acetylating to non-toxic metabolite, they use a different pathway that creates toxic metabolites that lead to hypersensitivity reactions

Question 21

What breed is especially sensitive to potentiated sulfonamides?

Answer 21

Dobermans (and Rottweilers?)

Question 22

T/F: Potentiated sulfonamides can cause severe cutaneous reactions known as Steven’s-Johnson syndrome (toxic epidermal necrolysis)

Answer 22

True - considered to be a dermatological emergency

Question 23

How can prolonged potentiated sulfonamide administration affect the eye?

Answer 23

KCS - toxic to lacrimal gland

Question 24

Avoid giving _______ to animals with _____thyroidism

Answer 24

Potentiated sulfonamides

Hypothyroidism

Block formation of thyroxine and thyronine

Question 25

What are macrolides most commonly used for in horses? What group? What are the potential side effects?

Answer 25

Rhodococcus
2-4mo
Diarrhea (especially in older horses)

Question 26

Macrolides have ________ properties and can be used to increase GI motility.

Answer 26

Pro-kinetic

Question 27

Why drugs do we often give macrolides with?

Answer 27

Rifampin!

Question 28

Macrolides are capable of causing anhidrosis in foals. What does this mean? Why is this bad?

Answer 28

Cannot sweat
Bad b/c horses thermoregulate thru sweat
Leads to hyperthermia, respiratory distress, and death

Question 29

Lincosamides can cause fatal antibiotic-induced diarrhea in what two species?

Answer 29

Horses and rabbits

Question 30

What species is most susceptible to the dose-dependent hematologic toxicity see with chloramphenicol? Why?

Answer 30

Cats - lack of glucuronyl transferase

Question 31

Metronidazole is associated with _________

Answer 31

Neurotoxicity - severe ataxia, vertical or rotary nystagmus, seizures