Antiprotozoals & Antivirals

Question 1

Monensin (“Reumensin”)
- 3 uses
- Toxic to what species?

Answer 1

• Antiprotozoal
  1. Anticoccidial - lipophilic drug that complex with cations and then transport these into the coccidium. Osmolarity is altered and coccidia are incapable of osmoregulation to death or reduced replication
  2. Growth promotants - improves ruminal efficiency by increasing propionic acid relative to acetic and butyric acid - main use in growing dairy cows and feed lot finishers
  3. anti-bloat - decreases methane production

**Toxic in horses

Question 2

Potentiated sulphonamides
- stats or cides?
- MOA
- primarily used for in production animals and small animals

Answer 2

• Antiprotozoal
• anticoccidial - coccidiostats or coccidiocides depending upon which TMS - coccidia combination
• MOA protozoa must synthesize their own folate - sulphonamides and trimethoprim affects this synthesis and conversion
• primary use in production animal coccidiosis & small animal toxoplasmosis

Question 3

Toltrazuril (“Baycox”)
- stat or cidal?
- used primarily for what
- important in what industry?

Answer 3

• Antiprotozoal
• coccidiocidal - inhibits nucellar division and mitochondrial activity during INTRAcellular stages of lifecycle
• used primarily for coccidiosis in intensively raised animals
• Important in the poultry industry!!

Question 4

Clindamycin
- MOA
- used for treating

Answer 4

• Antiprotozoal (also a antibiotic (other))
• MOA - inhibits protozoal protein synthesis
• used for treating feline and canine toxoplasmosis

Question 5

Metronidazole “Flagyl”
- MOA
- effective against

Answer 5

• Antiprotozoal
• MOA metabolized within the parasite to produce toxic metabolites which attack DNA
• effective against tri(trichomonas) - avian, bovine, cats
• effective against giardia - dogs

Question 6

Aciclovir
- MOA
- effective against what virus?
- toxic to cats when given via what route of administration?

Answer 6

• Antivirals
• MOA
  > Creates a defective nucleotide that the virus needs to replicate (instead of the virus using the non-defective one our body needs) = terminates DNA synthesis
  > Is also an inhibitor of viral polymerase (which builds DNA) - required by the virus
  SO means the virus cannot replicate
• Eg. against herpesvirus
• toxic to cats when given systemically - so only topical!

Question 7

Famciclovir
- only safe and effective antiviral for what?

Answer 7

• Antiviral
• only safe and effective oral antiviral for feline herpesvirus in the eye

Question 8

L-Lysine
- MOA

Answer 8

• Antiviral
• MOA - blocks the availability of arginine necessary for herpesvirus replication

Question 9

Remdesivir
- Game changer for what?
- MOA

Answer 9

• Antiviral (parenteral, IV, SC)
• Game changer for feline infectious peritonitis (FIP) - caused by feline coronavirus (FCoV)
• MOA Inhibitor of viral polymerase (which builds the RNA) = virus cannot replicate

Question 10

G2-441524
- Game changer of what?
- MOA

Answer 10

Anti-viral (oral)
- Game changer for feline infectious peritonitis (FIP) - caused by feline coronavirus (FCoV)
- MOA Inhibitor of viral polymerase (which builds the RNA) = virus cannot replicate

Question 11

Isospora and eimeria (C)

Answer 11

common in poultry

Question 12

Cryptosporidium (C)

Answer 12

common in production animals - GIT
oral azithromycin or oral tylosin used for dog/cat infections

Question 13

Trichomonas & Tritrichomonas

Answer 13

avian - GIT
production animals - GIT

Question 14

Toxoplasma & Neospora (C)

Answer 14

small animal - musculoneurological

Question 15

Giardia

Answer 15

not universally accepted as a significant vet pathogen

Question 16

coccidia life cycle

Answer 16

oocysts in faeces –> sporulate –> sporulated oocysts ingested –> usually GIT disease –> faecal oral transmission