Chapter 14 Antimicrobials

Question 1

Cell Wall Agents: Natural Penicillins

penicillin G

Answer 1

Narrow spectrum

Distribute to most body fluids and bone

Parenteral

V/D, hypersensitivity reactions

Question 2

Cell Wall Agents: Broad Spectrum Penicillin

amoxicillin

ampicillin

Answer 2

Broader spectrum than natural penicillin

Some gram-negative bacteria

Semi-synthetic

Oral

Parenteral

Question 3

Cell Wall Agents: Beta Lactamase Resistant Penicillins

cloxacillin

Answer 3

Narrow Spectrum

Bacteria produce beta lactamase

Enzyme destroys beta lactam structure

Used for:

• dry cows

Intramammary

Question 4

Cell Wall Agents: Potentiated Penicillins

amoxicillin and clavulanic acid (Clavamox)

Answer 4

Chemically combined with another drug to enchance effects

Beta lactam ring protector

Beta lactamase resistance

Oral

Question 5

Cell Wall Agents: Cephalosporins

cephalexin

cefazolin

cefovecin (Convenia)

Answer 5

Broad spectrum antibiotic

Bactericidal

Semi-synthetic

Beta lactam ring

Used for:

• respiratory
• bone
• skin
• soft tissue infections

V/D

Oral

IV

SC q 14 days

Question 7

Cell Wall Agents: Bacitracin

bacitracin

Answer 7

Bactericidal

Gram-positive

polypeptide - no beta lactam ring

Topical

Question 8

Cell Membrane Agents

polymyxin B

Question 9

Protein Synthesis Agents: Aminoglycosides

gentamycin

Answer 9

Bactericidal

Gram-negative

Used for:

• serious systemic infections

Parenteral

Nephrotoxic and ototoxic

Question 10

Protein Synthesis Agents: Aminoglycosides

neomycin

Question 11

Protein Systhesis Agents: Tetracyclines

doxycycline

Answer 11

Braod spetrum

Used for:

• tick borne rickettsial organisms
• Lyme disease and leptospirosis
• toxoplasmosis and UTI
• pneumonia
• shipping fever
• calf scours
• pink eye

CNS- crosses BBB

Oral

V/D

Question 12

Protein Synthesis Agents: Florfenicol

florfenicol

Answer 12

Used for:

• bovine respiratory disease

Parental

Question 13

Protein Synthesis Agents: Macrolides

tylosin

Question 14

Protein Synthesis Agents: Lincosamides

pirlimycin

Answer 14

Used for:

• lactating dairy cows with mastits

Intramammary

Question 15

Protein Synthesis Agents: Aminocoumarins

novobiocin

Answer 15

Narrow spectrum

Some gram-positive cocci

Used for:

• dairy cattle to treat or prevent mastitis

Intramammary

Question 16

Antimetabolites: Sulfonamides

S-125

S-250

Answer 16

Local action; not absorbed from GI tract

Small animals used for:

• coccidia
• protozoa

Oral

Question 17

Nucleic Acid Agents: Fluoroquinolones

enrofloxacin (Baytril)

marbofloxacin (Zenequin) (Pfizer)

Answer 17

Broad spectrum

Bactericidal

Large animal used for:

• respiratory infections

Small animal used for:

• serious systemic and CNS (BBB) infections
• local ear infection

Injectable

Injectable, Oral, Topical

Not in youngs animals, blindness in cats

Extral label used in food animals is prohibited

Question 18

Nucleic Acid Agents: Nitroimidazoles

metronidazole

Answer 18

Bactericidal

Antibacteral and antiprotozoal

Used for:

• diarrhea caused by bacterial overgrowth

Neurologic signs in cats

Oral or Parenteral

Question 19

Polyene Antifungal Agents

nystatin

Question 20

Imidazole Antifungal Angents

itraconazole

Answer 20

Cause leakage of fungal cell membrane

Favoured for small animals; less hepatotoxic

Used for:

• dermatophytes
• systemic

Oral

Question 21

Imidazole Antifungal Angents

miconazole

clotrimazole

Question 22

Antiviral Drugs

trifluridine

Answer 22

Used for:

• feline herpes

Topically in eye

Question 23

Antiviral Drugs

interferon

Answer 23

Used for:

• feline ocular herpes virus
• feline leukemia virus

Oral