Antiviral Agents

Question 1

Amantadine (Rimantadine) MOA

Answer 1

Inhibition or delay uncoating process → interferes with the early stage of viral mRNA transcription
NMDA receptor antagonist

Question 2

Side effects of Amantadine

Answer 2

Fever, and CNS effects
Aerosol administration reduces toxicity

Question 3

Amantadine uses

Answer 3

Prophylaxis in Equine Influenza
Chronic pain for small animals

Question 4

Acyclovir (Acycloguanosine) MOA

Answer 4

Selective for viral cells
Phosphorylated by viral thymidine kinase (not by host cell enzyme)

Question 5

Alternatives to Acyclovir

Answer 5

Valacyclovir and deoxyacyclovir
prodrugs with higher bioavailability

Question 6

Acyclovir uses in humans

Answer 6

Herpes simplex 1 & 2
Varicella Zoster virus (chicken pox)

Question 7

Acyclovir uses in animals

Answer 7

Ocular herpesvirus infections in dogs and cats
Neonatal equine herpes, equine herpes myeloencephalopathy
Pacheco’s dz (parrots)

Question 8

Adverse effects of acyclovir

Answer 8

BM suppression
Nephrotoxic

Question 9

Idoxuridine, vidarabine and trifluridine MOA

Answer 9

Potent inhibitors of herpesvirus DNA synthesis
Inhibits DNA polymerase (misinterpretation of genetic code)

Question 10

Idoxuridine, vidarabine and trifluridine toxicity

Answer 10

Anemia, neutropenia, loss of hair

Question 11

Opthalmic idoxuridine uses

Answer 11

ELDU for K9 herpes1 and ulcerative keratitis
Ocular feline herpes1 infections

Question 12

Vidarabine uses

Answer 12

Topical ophthalmic use for herpetic keratitis

Question 13

Ophthalmic trifluridine uses `

Answer 13

Ulcerative keratitis associated with K9 herpes
Most potent drug for feline herpes1

Question 14

Ribavirin (virazole) MOA

Answer 14

Activated by viral phosphorylation and prevents the formation of mRNA and translation of viral genome → inhibitor of reverse transcription

Question 15

Ribavirin has broad antiviral activity against ______________

Answer 15

RNA and DNA viruses

Question 16

Ribavirin uses

Answer 16

Aerosol- resp. syncytial virus
Influenza, parainfluenza, bovine herpes, K9 distemper, bluetongue, Marek’s, feline calicivrius

Question 17

Zidovudine (ZDV)/ azidothymidine (AZT) MOA

Answer 17

Inhibitor of reverse transcriptase and inhibits viral replication

Question 18

Uses of Zidovudine (ZDV)/ azidothymidine (AZT)

Answer 18

FIV infected cats (delays onset of immunodeficiency)
Inhibits feline leukemia virus

Question 19

Oseltamivir (tamiflu) MOA

Answer 19

Neuraminidase inhibitor → prevents the release of new viral particles from infected cells

Question 20

Oseltamivir uses

Answer 20

K9 parvo enteritis- improves clinical condition
Prevention and tx of equine influenza A

Question 21

Adverse of oseltamivir

Answer 21

Needs to be given early (24-72 hr= peak replication)
Reduce efficacy of vx (live- avoided 2w before and 48hr after)

Question 22

Interferon

Answer 22

Cytokines
No cross-species protection
Alpha, beta and gama

Question 23

Interferon alpha, beta and gamma

Answer 23

A & B= broad range
G= activity against intracellular pathogens

Question 24

IF alpha

Answer 24

Resp. viruses in cats

Question 25

Omega interferon (feline)

Answer 25

Recombinant feline interferon alpha
Improve clinical condition for FeLV or FIV
Atopic derm and parvo enteritis in dogs

Question 26

Omega interferon contraindication

Answer 26

Don’t use in dogs <1m or cats <9w

Question 27

The following antiviral agent is used only topically (due to systemic toxicity) for ulcerative keratitis associated with K9 herpesvirus 1:

Answer 27

Trifluridine

Question 28

Which of the following drug is used in adjunct therapy in chronic pain in dogs, although it’s classified as antiviral agent?

Answer 28

Amantadine

Question 29

Which of the following drug is a neruaminidase inhibitor used to improve clinical condition of K9 parvo enteritis and prevent equine influenza A?

Answer 29

Oseltamivir