Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ID Pharm > Antivirals > Flashcards

Antivirals Flashcards

1
Q

6 Steps in viral infection and replication

A
  1. Adsorption
  2. Penetration
  3. Viral Genome Replication
  4. Assembly
  5. Maturation
  6. Release
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What do the guanine nucleoside analogs do and what are they?

A

Anti-HSV and Anti VZV
Acyclovir (Zovirax)
Valacyclovir (Valtrex)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Guanine nucleoside analog MOA

A

Drugs phosphorylated by viral thymidine-kinase, then metabolized by host cell kinases to nucleotide analogs
The analog inhibits viral DNA-polymerase
Only actively replicating viruses are inhibited

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Acyclovir (Zovirax) Indications and ROA

A 
Topical, oral, IV
HSV1 and 2
VZV
Maybe EBV
DOC for HSV lesions, HSV encephalitis, HSV infx in immunocompromised or pregnant
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Acyclovir (Zovirax) PK, Saftey, and monitoring

A 
20-30% oral bioavailability
Wide distribution including CNS
Renal excretion > 80%
Half-life: 2-5 hrs
Preg Cat B
Lactation Safe
IV: CrCl 20-25 give q12h, CrCl <25 q24hr
Hepatic: no change needed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Acyclovir (Zovirax) MOA

A

Inhibits viral synthesis of DNA
Phosphorylated to acyclovir monophosphate
Cellular enzymes convert to acyclovir triphosphate
Competes with viral deoxyguanosine triphosphate for viral DNA polymerases
Lacks 3’ hydroxyl group to prevent further nucleoside attachment - chain termination
Inactivates viral DNA polymerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Acyclovir (Zovirax) Dose

A 
Varies with infection and severity
200, 400, 800 mg tablets, 200/5mL liquid, IV
VZV: 800 mg PO 4-5/day x 7-10 days
HSV:
1st: 400 mg PO 3-4/day x 7-10 days
Recurrence: 400 mg PO TID x 5 days
Suppression: 400 mg PO BID
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Acyclovir (Zovirax) Adverse Effects

A

Reversible renal toxicity - crystallization in tubules
Neuro Sx: encephalopathic somnolence, halluc, confus, coma
TTP/HUS in immunocompromised
GI, HA, rash, photosensitivity, Anemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Acyclovir (Zovirax) Resistance

A 
Defined as MIC >2-3 mcg/mL
Mostly occurs in immunocompromised
Reduced or absent thymidine kinase
Altered TK substrate specificity
Alterations in DNA polymerase
Cross resistance to famciclovir and valacyclovir
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Famciclovir (Famvir) MOA

A

Converted to penciclovir triphosphate in liver and intestines, which has a lower affinity for viral DNA polymerase, but a longer intracellular half-life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Famciclovir (Famvir) Use and Spectrum

A

PO only

HSV 1 & 2, VZV, lesser EBV, invitro HBV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Famciclovir (Famvir) PK

A

77% oral bioavailability
1st pass = conversion to penciclovir
renal excretion > 80%
Half-life 2-3 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Famciclovir (Famvir) Saftey and Monitoring

A

Preg Cat B
Lactation: safety unknown
Renal: adjust if CrCl < 40
Hepatic: no adjustment needed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Famciclovir (Famvir) Dose

A 
125, 250, 500 mg tablets
Zoster: 500 mg TID x 7 days
HSV: 
1st: 250 mg PO TID x 7-10 days
Recurrence: 1000 mg PO bid x 1 day w/in 6 hrs of Sx
Suppression: 250 mg PO bid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Famciclovir (Famvir) Adverse Effects

A

Neutropenia, thrombocytopenia
Neuro Sx: somnolence, halluc, delirium
GI, HA, fatigue
elevated LFTs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Famciclovir (Famvir) Resistance

A

Mutations in TK or DNA polymerase
Cross resistance with acyclovir in TK negative strains - may still have activity
Resistance to HBV due to L528M point mutation in viral DNA polymerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Valcyclovir (Valtrex)

A

Prodrug of Acyclovir
rapidly and almost completely converted to acyclovir via 1st pass metabolism
Same MOA, SOA, and mech of resistance as acyclovir

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Valcyclovir (Valtrex) Advantage

A

better oral bioavailabiltiy = 55%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Valcyclovir (Valtrex) PK

A 
55% oral bioavailability
1st pass metabolism to acyclovir
Food does not affect absorption
> 50% renal excretion
Half-life 2-3 hours
ORAL
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Valcyclovir (Valtrex) Safety and Monitoring

A

Preg Cat B
Lactation Safe
Renal: adjust if CrCl < 30
Hepatic: none

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Valcyclovir (Valtrex) Dose

A 
500, 1000 mg tabs
Zoster: 1000 mg PO tid x 7-10 days
HSV:
1st: 1000 mg PO bid x 7-10 days
Recurrence: 500 mg PO bid x 3-5 days
Suppression: 1000 mg PO qday
22
Q

Valcyclovir (Valtrex) AE

A

Reversible renal toxicity - crystallization in tubules
Neuro Sx: encephalopathic somnolence, halluc, confus, coma
TTP/HUS in immunocompromised
GI, HA, rash, photosensitivity, Anemia

23
Q

Topicals for HSV

A

Penciclovir (Denavir 1% cream) - HSV1
Docosanol (Abreva OTC) - HSV1
Trifluridine (Viroptic) - HSV keratoconjunctivitis

24
Q

Penciclovir (Denavir 1% cream)

A

For orolabial HSV
topical guanine analog similar to acyclovir
apply every 2 hrs while awake

25
Q

Docosanol (Abreva OTC)

A

For orolabial HSV
Active against broad range of lipid-envelop viruses
MOA: interferes with viral fusion to host cell
Apply 5 times/day until healed (10 days)
Shortens healing by 0.7 days

26
Q

Trifluridine (Viroptic)

A

For HSV keratoconjunctivitis
1 drop q2h (max 9 drops/day)
Active against acyclovir resistant strains
Active against vaccinia virus and smallpox

27
Q

Anti-CMV Agents

A

Ganciclovir (Cytovene)

28
Q

Ganciclovir (Cytovene) - ROA and Spectrum

A 
ROA: oral, IV, intraocular
Spectrum:
CMV/EBV - 10x potency of acyclovir
HSV/VZV - equal to acyclovir
Human Herpes Virus 6
29
Q

Ganciclovir (Cytovene) DOC

A

DOC for CMV retinitis in immunocompromised

Prevention of CMV disease in transplant pts

30
Q

Ganciclovir (Cytovene) PK

A

50% oral bioavailability
Excreted unmodified in the urine
Renal excretion >90%
Half-life: 2-4 hrs

31
Q

Ganciclovir (Cytovene) Safety and Monitoring

A

Preg Cat C
Lactation unsafe
Renal: adjust if CrCl < 50
Hepatic: not defined

32
Q

Ganciclovir (Cytovene) MOA

A

Competes with deoxyguanosine triphosphate
In CMV, viral phosphotransferase converts to ganciclovir triphosphate
Contains 3’-hydroxyl group allowing for DNA to continue

33
Q

Ganciclovir (Cytovene) Adverse Effects

A 
Reversible pancytopenia
Fever
Rash
Phlebitis (IV)
Confusion
Renaly Dysfxn
Psych disturbances
Seizures
34
Q

Influenza Agents

A

Oseltamivir (Tamiflu)
Zanamivir (Relenza)
Amantadine
Rimantadine

35
Q

Neuraminidase Inhibitors

A

Oseltamivir and Zanamivir
Neuraminidase - flu enzyme essential for viral replication
Neuraminidase inhibitors prevent release of new virions and their spread from cell to cell
Effective against flu A and B
Do not interfere with flu A vaccine
For prophylaxis and treatment

36
Q

Oseltamivir (Tamiflu) - Class and MOA

A

Oral neuraminidase inhibitor
Cleaves terminal sialic acid residue on glycoconjugates and destroys receptors
newly formed virions adhere to cell surface and limit spread

37
Q

Oseltamivir (Tamiflu) Spectrum and AE

A

Flu A and B in adults and peds
Avian influenza
H5N1 disease
AE: N/V, HA

38
Q

Oseltamivir (Tamiflu) Dosing

A

A&B Tx: 75 mg PO bid x 5 days w/in 48 hrs of Sx onset

Prophylaxis: 75 mg PO bid x 5 days w/in 48 hrs of exposure

39
Q

Zanamivir (Relenza)

A

Neuraminidase inhibitor
Given via inhalation: 2 puffs bid x 5 days
Spectrum: uncomplicated flu A&B, some avian flu
AE: nasal and throat discomfort, bronchospasm
Not recommended in pts with severe flu, asthma or COPD

40
Q

Amantadine (Symmetrel) & Rimantadine (Flumadine)

MOA, Spectrum, AE

A

MOA: prevents release of viral nucleic acid into host cell
Spectrum: Flu A (resistance is frequent)
AE: seizures, anticholinergic, CNS, edema, blurry vision
Much resistance - not recommended in US

41
Q

Amantadine PK and off-label

A

50-90% bioavailability
Crosses BBB (Rimantadine does not)
Oral administration
Used for extrapyramidal Sx and Parkinsonism

42
Q

Ribavirin Class and MOA

A

Purine nucleoside analog

MOA: inhibits RNA polymerase - not well understood

43
Q

Ribavirin Spectrum

A

DNA and RNA viruses: flu, HCV, parainfluenza, RSV, lassa virus

44
Q

Ribavirin Uses

A

DOC: RSV bronchiolitis and pneumonia in hospitalized children via aerosol
Alternative for: flu, parainfluenza, measles in immunocompromised pts
Used in combo with interferons or sovaldi for HCV

45
Q

Ribavirin ROA and Special Pops

A 
IV through CDC
Oral and inhalation
Preg Cat X
Lactation unsafe
BBW: hemolytic anemia
46
Q

Ribavirin AE

A

Resp. deterioration
Depression, suicidal ideation, psych effects, anxiety
Bacterial Infxs
Fatigue, dizziness

47
Q

Causes of Hepatitis

A 
Refers to swelling of liver in response to:
Drugs
Toxins
Excessive alcohol
Infx from bacteria or viruses
48
Q

Hep A

A

typically spreads when infected individuals improperly handle food or water

49
Q

Hep B

A

transmitted via sexual intercourse, needle sharing, or contact with contaminated blood
Vaccine since 1980’s
Chronic Tx: interferon, NRTI, liver transplant

50
Q

Hep C

A

More likely to cause permanent liver damage
Genes mutate fast
New genotypes make vaccine impossible
Tx: interferon plus ribavirin

51
Q

NRTI

A

Nucleoside Reverse Transcriptase Inhibitors
Emtricitabine
Tenofovir
Entecavir - guanosine analog - lamivudine resistant strains
Lamivudine - cytosine analog HBV

52
Q

Hepatitis Anti-viral Drugs

A 
Interferons
Lamviudine - cytosine analog HBV
Entecavir - guanosine analog - lamivudine resistant strains
Ribavirin - Hep C with interferons
Sofosbuvir (Sovaldi) - Hep C
Simeprivir (Olysio) - Hep C
Ledipasvir-Sofosbuvir (Harvoni) - Hep C

ID Pharm (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions