Antimicrobials

Question 1

Antifungals are…

Answer 1

Chemicals used to treat diseases caused by fungi (mold or yeast)

Question 2

Superficial vs Systemic fungal diseases

Answer 2

Superficial: ringworm
Systemic: blastomycosis

Question 3

Categories of antifungal agents (4)

Answer 3

1. Polyene
2. Imidazole
3. Anti-metabolic
4. Superficial

Question 4

Polyene Antifungals
1. Work by
2. Examples (2)

Answer 4

1. Binding to the fungal cell membrane
2. Examples:
   - Nystatin (used orally for Candida albicans infections)
   - Amphotericin (used IV for systemic mycoses)

Question 5

T/F: Amphotericin, a polyene antifungal, is extremely nephrotoxic, light sensitive, and can precipitate out of solution.
It should only be used for life-threatening systemic fungal infections.

Answer 5

True

Question 6

Imidazole Antifungals
1. Work by
2. Examples (3)
3. Precautions

Answer 6

1. Causing leakage of the fungal cell membrane
2. Examples
   - Ketoconazole
   - Itraconazole
   - Fluconazole
3. Precautions:
   - Liver or kidney damage is a major concern with this class of drugs, especially because they are usually given for months to years.

Question 7

Griseofulvin (antimetabolic)
1. What kind of agent? What is it?
2. Precautions (2)
3. How it should be given

Answer 7

1. Systemic drug given to treat dermatophytes (ringworm). Accumulates in keratin; prevents fungal mitosis.
2. Precautions
   - Potential for liver and/or bone marrow damage especially in cats.
   - Teratogenic! Don’t use in pregnant animals.
3. Best absorption if given with fatty meal

Question 8

Nystatin
What kind of agent? What is it?

Answer 8

Superficial agent given orally to treat yeast infections of the mouth or GI tract (thrush).
- Not absorbed systemically

Question 9

Nystatin topical ointments
Common antifungal ingredients include (4)

Answer 9

1. Ketoconazole
2. Clotrimazole (in Otomax)
3. Nystatin (Panalog)
4. Thiabendazole (Tresaderm)

Question 10

Viruses are…

Answer 10

Intracellular invaders that alter the host cell’s metabolic pathways

Question 11

Antiviral drugs act by preventing viral ___ of the host cell or by ___ the virus’s production of ___ or ___.

Answer 11

1. Penetration
2. Inhibiting
3. RNA or DNA

Question 12

Antiviral drugs used are (5)

Answer 12

1. Acyclovir
2. Interferon
3. Lysine
4. Oseltamivir (Tamiflu)
5. Zidovudine (AZT)

Question 13

Acyclovir
1. Interferes with…
2. Treats (1)

Answer 13

1. The virus’s synthesis of DNA.
2. Treats feline herpes virus infections.

Question 14

Interferon
1. Protects….
2. Used to treat (3)

Answer 14

1. Host cell from a number of different viruses
2. Treats
   - Ocular feline herpes
   - FeLV
   - Canine papillomavirus

Question 15

Lysine is an ___ acid that might be helpful in suppressing feline ___. It competes with arginine in virus ___ building (recently controversial).

Answer 15

1. Amino
2. Herpes
3. Structure

Question 16

Oseltamivir (tamiflu)
1. Prevents…
2. Treatment use in…

Answer 16

1. Infected cell from releasing virus
2. Possible use in canine & equine influenza

Question 17

Zidovudine (AZT)
1. Commonly used in what species?
2. Helpful in…

Answer 17

1. Cats!
2. FIV
   - Not so much FeLV

Question 18

T/F: In general, anti-viral drugs are expensive but are overall safe to use in cats & poultry

Answer 18

False! While they are expensive, they are TOXIC in cats and ILLEGAL to use in poultry.