17 Antibiotics

Question 1

What are the two types of percutaneous drug administration?

Answer 1

Topical (local) and transdermal (systemic)

Question 2

Regarding the skin, what is the biggest barrier for drug absorption?

Answer 2

Stratum corneum

Question 3

How do polar compounds travel through the skin?

Answer 3

Intracellular (straight through cells)

Question 4

How do lipophilic compounds travel through the skin?

Answer 4

Intercellular (weaving in between cells)

Question 5

T or F: the epidermis contains enzymes that may metabolize pharmaceuticals

Answer 5

True

Question 6

What classes of antibiotics are B-lactam antibiotics?

Answer 6

Penicillins and cephalosporins

Question 7

Are B lactam antibiotics time or concentration dependent?

Answer 7

Time

Question 8

What is the MOA of B-lactam antibiotics?

Answer 8

Disruption of the synthesis and integrity of the peptidoglycan cell wall

Question 9

What is the function of clavulanic acid?

Answer 9

Beta-lactamase inhibitor

Question 10

What is an example of a lincosamide?

Answer 10

Clindamycin or lincomycin

Question 11

Are lincosamides time or concentration dependent?

Answer 11

Time dependent

Question 12

What is the MOA of lincosamides?

Answer 12

Interferes with protein synthesis by binding to the 50S ribosomal subunit

Question 13

Which class of antibiotics is contraindicated in horses and why?

Answer 13

Lincosamides, due to enterocolitis

Question 14

Are potentiated sulfonamide antibiotics time or concentration dependent?

Answer 14

Time dependent

Question 15

What is the MOA of sulfonamides?

Answer 15

Inhibition of folic acid synthesis

Question 16

Why are sulfa antibiotics mixed with ormetoprim or trimethoprim?

Answer 16

Alone these compounds are all bacteriostatic, but when combined they are synergistic and become bacteriocidal

Question 17

What is the MOA of tetracyclines?

Answer 17

Inhibits protein synthesis by binding to the 30S ribosomal subunit

Question 18

Are tetracyclines time or concentration dependent?

Answer 18

Time dependent

Question 19

What antibiotic class can cause esophageal strictures in cats?

Answer 19

Tetracyclines

Question 20

What is the MOA of chloramphenicol?

Answer 20

Inhibition of protein synthesis by binding to the 50S ribosomal subunit

Question 21

When are fluoroquinolones indicated?

Answer 21

Complicated bacterial infections

Question 22

Are fluoroquinolones time or concentration dependent?

Answer 22

Concentration dependent

Question 23

What is the MOA of fluoroquinolones?

Answer 23

Inhibition of DNA replication/transcription by inhibiting DNA gyrase

Question 24

What is the MOA of aminoglycosides?

Answer 24

Inhibits translation by binding the 30S ribosomal subunit

Question 25

Are aminoglycosides time or concentration dependent?

Answer 25

Concentration dependent

Question 26

What factors effect percutaneous absorption?

Answer 26

Hydration (more hydrated = better absorption), stratum corneum thickness/integrity, cutaneous blood flow

Question 27

What are the mechanisms of beta lactam resistance?

Answer 27

-Reduced penetration through cell wall -Efflux via pumps -Altered penicillin binding proteins -Production of beta lactamases

Question 28

What are the adverse effects of beta lactam antibiotics?

Answer 28

-Intestinal flora disturbance -Hypersensitivity -CNS effects at high concentrations

Question 29

What are the adverse effects of lincosamides, and which species are they typically observed in?

Answer 29

Bacterial overgrowth, enteritis/enterocolitis in ruminants and horses

Question 30

What are the adverse effects of potentiated sulfonamides?

Answer 30

-Crystalluria -Keratoconjunctivitis sicca -Hypersensitivity -Anemia & thrombocytopenia

Question 31

What are the adverse effects of tetracyclines?

Answer 31

-GI flora changes -Esophageal strictures in cats -Binding to bone and teeth

Question 32

What are the adverse effects of chloramphenicol?

Answer 32

-Anemia -GI disturbances

Question 33

What are the adverse effects of fluoroquinolones?

Answer 33

-Retinal degeneration in cats -GI disturbance -Developmental arthropathy

Question 34

What are the adverse effects of aminoglycosides?

Answer 34

-Ototoxicity -Nephrotoxicity