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Flashcards in Antiviral I Deck (88)
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1

Viruses are Obligate intracellular parasites... Enter living cells and take over cell’s synthetic machinery.
________core surrounded by protein sheath or lipid-protein envelope.

Nucleic acid

2

Viral latency—

some can integrate into host chromosome allowing for recurrence of
clinical infection without re-exposure to viral agent.

3

After virus is absorbed or penetrates, it has to

uncoat proteins from nucleic acids

4

Main point of attack for antivirals

Any of the stages of the viral life cycle, so long as agent is nontoxic/ adequately specific

5

In many viral infections viral replication is at maximum when

viral replication reaches a maximum near the time clinical symptoms first appear (influenza, poxviruses)

6

Drugs are most effective if administered

before onset of symptoms, except herpes bc replication continues after appearance of clinical signs

7

Key issues of viral infections

side effects/toxicity
occurance of resistant strains
latent (dormant form) and recurrent infections
carcinogenicty
need to have competent host immune system

8

Uses of passive immunization

injection of immune globulin will block viral penetration before disease
can modify course of disease if given early enough IV or IM

9

Viral replication rate is reduced by blocking viral entry into cells; may allow for
active immunity to develop.

passive immunization

10

Prophylaxis against influenza A but not influenza B

Amantidine
~ works about 70% time

11

Amantidine is given to pts w/ influenza A and will

Reduces fever in 50% of patients and illness
duration by 1-2 days if given within first 2 days of illness

12

Issue we've seen with amantidine in the past few years

influenzas have been resistant

13

Mech for amantidine

Blocks viral uncoating by interfering with influenza A M2 protein (an ion
channel

14

Blocks viral uncoating by interfering with influenza A M2 protein (an ion
channel

Amantidine

15

Metabolism and excretion in amantidine

90% excreated unchaged in urine and REDUCE dose in RENAL disease

16

Toxicity of Amantidine

CNS effects
(slurred speech, anxiety, confusion, depression, headache)

17

inactive prodrug ...converted to active competitive inhibitor of influenza neuraminidases;

Oseltamivir

18

Oseltamivir is a prodrug that will inhibit neuramidase.. this is effective because

it interferes with viral release
from infected cells and viral penetration into respiratory epithelium

19

treatment of uncomplicated influenza A and B in patients ≥1 year old and prophy

Oseltamivir

20

Admin of Oseltamivir

2x day for 5 days with renal elimination

21

side effects in Oseltamivir

bronchitis, vomit, diahrrhea

22

decreases risk of serious influenza in 71% of adults and decrease chance of pnemonia in children

Oseltamivir

23

Interferes with DNA synthesis; thymidine analog.

Trifluridine

24

Trifluridine mech

interferes with DNA synthesis, thymidine analog

25

Uses of trifluridine

Ophthalmic herpes type 1 and 2 but not useful prophylactically

26

Ophthalmic herpes type 1 and 2 but not useful prophylactically

Trifluridine

27

guanosine derivative; inhibits DNA polymerase.
Phosphorylated form is produced 40-100x faster in infected cells by herpes thymidine kinase;
inhibits herpes DNA polymerase 10-30x more than host cell DNA polymerase; acts as a competitive inhibitor of dGTP and as a DNA chain terminator.

Acyclovir

28

acts as a competitive inhibitor of dGTP and as a DNA chain terminator

Acyclovir

29

Acyclovir mech

inhibits DNA polymerase by activing like a competitive inhibitor of dGTP and as DNA chain terminator

30

IV Drug of choice for serious systemic herpes simplex virus (HSV), including HSV encephalitis

Acyclovir