Pharm4

Question 1

Precautions of Aminoglycosides

Answer 1

• Use with caution in animals w/ renal disease or poor renal blood perfusion
• Gentamicin, amikacin, kanamycin, and tobramycin should not be mixed w/ penicillin
• Inactivated by organic debris
• Not to be used in adult food animals

Question 2

Quinolones

Answer 2

• Newest antibiotic group
• Reserve use for treatment of more serious infections
• Examples: enrofloxacin, marbofloxacin, orbifloxacin, ciprofloxacin

Question 3

Mechanism of action of Quinolones

Answer 3

Disruption of bacterial DNA molecule

Question 4

Absorption of Quinolones

Answer 4

• Well absorbed after oral or parenteral administration
• GI absorption poor in mature ruminants- absorption in abomasum
• Absorbed more slowly in the presence of food

Question 5

Distribution, Metabolism, Elimination of Quinolones

Answer 5

• Distribution– penetrates most tissues, except CNS
• metabolized in by liver
• Elimination– metabolites excreted through urine and bile

Question 6

Spectrum of activity of Quinolones

Answer 6

• Proven efficacy against most G- and some G+ bacteria

- not effective vs. anaerobic bacteria

Question 7

Precautions of Quinolones

Answer 7

• May cause damage to articular cartilage of growing dogs and horses (<3yrs).
• Not recommended for pregnant animals- harmful to fetus
• Vomiting, nausea, diarrhea observed in some animals
• May cause crystal formation in urine

Question 8

Tetracyclines

Answer 8

• One of the oldest group of antibiotics
• Use mostly in large animals
• Examples: tetracycline, oxytetracycline, doxycycline

Question 9

Mechanism of action of Tetracyclines

Answer 9

• Bind to bacterial ribosomes and disrupt protein synthesis

* Bacteriostatic

Question 10

Absorption of Tetracyclines

Answer 10

-Absorbed well after oral or parenteral administration
-These products interfere with absorption of tetracyclines from the GI tract:
 dairy products
 antidiarrheal agents
 antacids

Question 11

Distribution and Elimination of Tetracyclines

Answer 11

• Distribution– Distributed to most tissues, except CNS
• Elimination:
-Excreted through bile but most reabsorbed from intestine
-Most elimination occurs via renal excretion

Question 12

Spectrum of activity of Tetracyclines

Answer 12

Effective vs. G+ and G- bacteria (rickettsia, spirochetes, Chlamydia, Mycoplasma, salmon poisoning)

Question 13

Precautions of Tetracyclines

Answer 13

• Cause yellow discoloration of teeth and bones in young, growing animals
• Cause retardation of bone growth in the fetus
• Can cause vomiting, diarrhea, and anorexia
• Do not use in animals w/ renal disease
• Do not use in combination w/ penicillins or cephalosporins

Question 14

Sulfonamides and Potentiated Sulfonamides

Answer 14

• One of the oldest group of antibiotics used in animals
• Examples: sulfadimethoxine, sulfamethazine, sulfachlorpyridazine, sulfadiazine-timethoprim, sulfadimethoxine-ormetoprim

Question 15

Potentiated Sulfonamides

Answer 15

Have a sulfonamide mixed with another antibiotic. Increase the spectrum of activity.

Question 16

Mechanism of action of Sulfonamides and Potentiated Sulfonamides

Answer 16

Interfere with the formation of folic acid by bacteria

Question 17

Absorption and Distribution of Sulfonamides and Potentiated Sulfonamides

Answer 17

Absorbed well after oral administration

Distributed well to body tissues, except CNS

Question 18

Metabolism and Elimination of Sulfonamides and Potentiated Sulfonamides

Answer 18

Metabolized by the liver

Elimination– Metabolites are excreted in urine; unchanged molecules are also excreted in urine

Question 19

Spectrum of activity of Sulfonamides and Potentiated Sulfonamides

Answer 19

Effective vs. G+ and G- bacteria, some protozoa

Question 20

Precautions of Sulfonamides and Potentiated Sulfonamides

Answer 20

• Allergic reactions have been reported: fever, facial swelling, rashes, shock
• Bone marrow suppression can occur w/ prolonged use
• Can cause KCS in some dogs
• May cause crystal formation in urine

Question 21

Metronidazole

Answer 21

• Effective vs. anaerobic bacteria (Clostridium) and some protozoa (Giardia)
• Anti-iflammatory effect in GI tract
• Toxicity possible with high dose and prolonged useà CNS abnormalities

Question 22

Lincosamides

Answer 22

• Often used to treat G+ anaerobic bacterial infections in animals
o Examples: lincomycin, clindamycin

Question 23

Mechanism of action of Lincosamides

Answer 23

Bind to bacterial ribosome and interfere w/ protein synthesis

Question 24

Absorption and Distribution of Lincosamides

Answer 24

Absorbed well after parenteral and oral administration

Good distribution to body tissues, except CNS

Question 25

Metabolism and Elimination of Lincosamides

Answer 25

Metabolized by the liver | Excreted through urine and bile

Question 26

Spectrum of activity of Lincosamides

Answer 26

Effective vs. G+ bacteria, anaerobic bacteria, protozoa (Toxoplasma)

Question 27

Precautions of Lincosamides

Answer 27

- Can cause vomiting and diarrhea - Do not use w/ antidiarrheal products - Do not use in guinea pigs, hamsters, or rabbits

Question 28

Chloramphenicol

Answer 28

* Powerful broad spectrum antibiotic used only occasionally in animals * Should not be used in food animals

Question 29

Mechanism of action of Chloramphenicol

Answer 29

Binds the bacterial ribosome and interferes w/ protein synthesis

Question 30

Absorption and Distribution of Chloramphenicol

Answer 30

Absorbed well after oral administration | Distribution– Penetrates all tissues, including the CNS!!

Question 31

Metabolism and Elimination of Chloramphenicol

Answer 31

Metabolized by liver | Excreted in urine and bile

Question 32

Spectrum of activity of Chloramphenicol

Answer 32

Effective vs. G+ and G- bacteria (rickettsia, Chlamydia, Mycoplasma)

Question 33

Precautions of Chloramphenicol

Answer 33

- Can cause bone marrow suppression in mammals - Do not use in animals w/ liver disease - Cats have a decreased ability to metabolize chloramphenicol - Do not use in combination w/ penicillins or cephalosporins