Localized therapy and shipping fever

Question 1

What are 4 ways to localize antimicrobial therapy in a patient?

Answer 1

• Intramammary infusion
• Nebulization
• Regional limb perfusion
• Bead therapy

Question 2

To treat mastitis, what are some considerations in choosing an agent?

Answer 2

• Environmental or Contagious mastitis
• Severity of clinical signs, local vs systemic
• Culture results
• Banned agents
• Withdrawl time
• Reserve systemic antibiotics for only SEVERE clinical mastitis cases

Question 3

What are the advantages and disadvantages of nebulization?

Answer 3

Advantages
– Direct delivery of drug to affected tissue
– Lower drug dose required
– Rapid onset of action
– Avoid systemic side effects
– Alter particle size to maximize delivery to appropriate site (upper vs lower tract)
Disadvantages
– Irritation of airway
– Bronchoconstriction
– Lung contamination if drug delivery device is contaminated
– Difficult to administer in some patients
– Duration and frequency of administration
– Access to blocked peripheral airway

Question 4

What are the advantages and disadvantages of regional limb perfusion?

Answer 4

Advantages
– Achieve high local concentrations, especially in difficult to penetrate and low vascularized tissues
– Decrease systemic toxicity
Disadvantages
– Requires maximal sedation or general anesthesia
– Potential for iatrogenic infection

Question 5

What are the advantages and disadvantages of localized PMMA bead therapy?

Answer 5

Advantages
– Great for refractory orthopedic sepsis
– Prolonged release of antibiotics in infected site
– No systemic effects
Disadvantages
– Allergic reaction, carcinogenicity, toxicity at site
– Beads are NOT absorbable
– Typically need surgery to remove beads

Question 6

How are antimicrobial beads made?

Answer 6

PMMA: antibiotic impregnated polymethylmethacrylate beads, Aminoglycosides used most commonly, concentration-dependent

Question 7

What factors should you consider when choosing an agent for inclusion in beads?

Answer 7

PMMA SOLIDIFICATION CAUSES AN
INTENSE EXOTHERMIC REACTION! Must use heat-stabile agents

Question 8

Which antimicrobials are limited for use in food animals?

Answer 8

• Chloramphenicol
• Fluoroquinolones (except label use)
• Dimetridazole, ipramidazole, other nitroimidazoles (Metronidazoles)
• Sulfonamides in dairy cattle over 24 months old (except specifically labeled)
• trimethoprim-sulfa – banned
• Aminoglycosides – voluntary ban

Question 9

What are the criteria that are required in order to use a drug in a way that is not on the label (extra-label usage)?

Answer 9

• Valid veterinarian-client-patient relationship
• No effective approved drug
• Health/well being is jeopardized
• Animal is properly identified
• Adequate withdrawal times are established
• No residue violations result