6/11- Antiviral Therapy Flashcards Preview

Term 5: Behavioral Science > 6/11- Antiviral Therapy > Flashcards

Flashcards in 6/11- Antiviral Therapy Deck (64):
1

Options for the Control of Viral Infections (broad)?

- Antivirals

- Isolation/quarantine (depends on pathogenesis and transmission route)

- Immunization (active; passive*)

- Immunomodulators

- Other: drug/alcohol use, physical activity, risky behaviors...

* e.g. Hep B in babies born to chronic Hep B mothers given Hep B Ig

2

Potential targets for antiviral agents?

- Adsorption

- Penetration

- Uncoating

- Early transcription

- Early translation

- Genome replication

- Late transcription

- Late translation

- Assembly

- Release

Want to target unique viral functions (limits toxicity)

3

What is key for the treatment of acute viral infections?

Early initiation of therapy (similar to Abx)

4

What are the most common causes of viral respiratory infections?

- Influenza

- RSV

5

Disease course of influenza?

Typical treatment?

What are some complications of influenza?

(Outbreaks each year)

Course of disease:

- Uncomplicated influenza typ gets better w/ or w/out treatment (symptomatic treatment- rest, OTC meds, fluids)

Complications:

- Bacterial infections

- Viral pneumonia

6

Treatment for influenza (1 method...oldish)? Mechanism?

Route?

Indications?

Resistance?

Amantidine and Ramantidine (trycyclic amines)

(not used anymore)

- Mechanism: interferes with uncoating

- Indications: prevention and treatment of influenza A virus infections

- Resistance: associated with mutations in the M2 protein (why these aren't used so much)

**not effective for Influenza B

7

How many strains of influenza circulate in a year?

Three:

- A (H1N1)

- A (H3N2)

- B

8

Efficacy of amantadine/rimantidine for influenza?

- Drugs decreased fever and virus shedding

- More rapid improvement in symptoms and activity levels

9

What other drugs (not targeting uncoating) can be used to treat Influenza?

- Mechanism:

- Route:

- Adverse effects:

- Indications:

- Neuraminidase inhibitors (sialic acid analogs)

- Mechanism: inhibit viral neuraminidase

- Route: oral (oseltamivir) or inhaled (zanamivir)

- Adverse effects: nausea/vomiting with oral oseltamivir; bronchospasm with inahled zanamivir

- Indications: Influenze A AND B infections (treatment and prophylaxis)

10

Which are preferred for the routine prevention of influenza: vaccines or antivirals?

Vaccines!

11

Which strains of influenza are resistant to Amantadine? (those that inhibit uncoating)

Alternative?

- A: H3N2

- A: H1N1

Alternatively use Oseltamivir or Zanamivir

12

Those at high risk for influenza complications?

- Children or adults > 65

- Chronic pulmonary (asthma), cardiovascular (not just HTN), renal, hepatic, hematological (sickle cell), metabolic (DM), or neurologic/neurodevelopment conditions

- Immunosuppression

- Pregnant/postpartum women (within 2 wks)

- < 19 and receiving long-term aspirin

- American Indians/Alaskan natives

- Morbidly obese (BMI > 40)

- Residents of nursing homes and other chronic-care facilities

13

What is Tamiflu?

Oseltamivir

14

What is Ribavirin?

- Mechanism

- Route

- Adverse effects

- FDA Indications

- Uses

Guanosine analog

- Mechanism: multifactorial; alters nucleotide pools and mRNA formation

- Route: aerosol (RSV), oral (HCV), IV

- Adverse effects: anemia, bronchospasm, teratogenic and mutagenic

- FDA Indications:

----Severe RSV dz in infants

----Chronic HCV (with PEG-IFN)

(also Lassa fever and Hantavirus infections)

Treatment for bronchiolitis: allowed earlier termination of ventilation

15

What are some common herpes viruses to consider?

- Herpes simplex

- Varicella-zoster

- CMV

16

What can be used to treat herpes viruses?

Acyclovir (guanasine analog; anti-viral)

17

What is acyclovir?

- Mechanism

- Route

- Adverse effects

- Indications

Guanosine analog (anti-viral)

- Mechanism: inhibits VIRAL TK, DNA pol; results in DNA chain termination

- Route: oral, IV, and topical form

- Adverse effects: phlebitis, headache, nausea, CNS toxicity, and crystalluria

Indications:

- Genital, perinatal, and CNS HSV

- Varicella and zoster

- HSV infections in immunocompromised hosts

18

What is one of the worst complications of HSV?

What can be used to prevent this?

HSV Encephalitis

(high morbidity/mortality rate)

Acyclovir

- Better results than older methods for all Glasgow levels

- Should start IV acyclovir for anyone who presents with altered mental status who may have HSV encephalitis until diagnostics come back

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19

Who should be treated for Varicella?

- Immunocompromised

- Possibly pregnant women

- Adolescents and adults

- Patients at high risk for complications

(Acyclovir for normal toddlers and children under 10 is efficacious but often not necessary)

20

What are some "off-label" uses of acyclovir?

Herpes simplex viruses:

- Gingivostomatitis

- Cold sores (penciclovir)

- Whitlow

- Ocular infections*

- Proctitis

- Eythema multiforme

*topical therapy is approved for use; other drugs available

Varicella-zoster virus

- Pneumonia

- Encephalitis

21

How do famciclovir and valacyclovir differ from acyclovir?

They are prodrugs and have greater oral bioavailability than acyclovir

22

What are famciclovir and valaciclovir used for?

Treatment of shingles

Suppression of genital HSV

Valacyclovir: primary genital HSV

Famciclovir: mucocutaneous HSV in immunocompromised

23

What is a drawback of acyclovir? Which form?

If given orally, have to take many times a day (poor compliance)

24

Valacyclovir has been associated with what in certain types of patients? Which patients?

TTP/HUS (hemolytic uremic syndrome)

- Pts with advanced HIV infection

- Bone marrow and renal transplant recipients

25

What drugs can be used to treat/suppress CMV infections? Routes of administration?

- Ganciclovir (IV)

- Valganciclovir (PO)

- Cidofovir (IV)

- Foscarnet (IV)

26

What is the major toxicity associated with ganciclovir?

Neutropenia

27

What is the major toxicity associated with valganciclovir?

Thrombocytopenia

28

What is the major toxicity associated with Cidovir? What kind of drug is it?

- Hematologic

- Renal

- Eye

- Neurologic

- GI

(nucleotide analog)

29

What is Foscarnet?

What is the major toxicity associated with it?

Pyrophosphate analog (IV for CMV)

- Renal (careful in pts with renal insufficiency)

- Neurologic

- Mineral/electrolyte abnormalities

30

T/F: if you are vaccinated for varicella (rather than contracting the disease) you are not at risk for Herpes zoster (reactivation)

False! Live vaccine, so can later get reactivation (just as if contracted the disease in the first place)

31

What an be used to treat chronic HBV infections (broadly)?

- Interferon alpha (cytokine), including PEG-IFN

- Nucleoside/tide analogs (DNA/Pol RT inhibitors)

32

Interferon alpha?

- Mechanism:

- Route:

- Adverse effects:

- Indications:

- Mechanism: induces antiviral state via induction of cellular genes

- Route: parenterally (only)

- Adverse effects: flu-like symptoms (feel crappy, fatigue, malaise), hematologic, neurologic, hepatic, and renal toxicity

- Indications: chronic HBV and HCV, HPV, and HHV8 infections

33

What are some nucleoside/tide analogs that can be used to treat chronic HBV?

Most commonly used?

- Lamivudine (S)

- Adefovir (T)

- Entecavir (S)

- Telbivudine (S)

- Tenofovir (T)

(Tide/Side)

Most common (if no HIV): Entecavir and Tenofovir

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34

T/F: Acyclovir can be used to treat CMV

False; must use ganciclovir or falganciclovir (or cidofovir or foscarnet)

35

What are the adverse events/toxicity associated with chronic HBV treatment with: Lamivudine?

Many people develop resistance, so never used by itself to treat HBV

- Fatigue

- HA

- Abdominal pain

- Myalgia

- Nasal symptoms

- Pancreatitis

36

What are the adverse events/toxicity associated with chronic HBV treatment with: Adefovir?

- Fatigue

- HA

- N

- Abdominal pain

- Nephro and hepatotoxicity

37

What are the adverse events/toxicity associated with chronic HBV treatment with: Entecavir?

- Lactic acidosis

- HA

- Diarrhea

- Arthralgia

- Insomnia

38

What are the adverse events/toxicity associated with chronic HBV treatment with: Telbivudine?

- Lactic acidosis

- Myopathy

- Neuropathy

39

What are the adverse events/toxicity associated with chronic HBV treatment with: Tenofovir?

Hepato and nephrotoxicity (biggest worry is renal insufficiency; monitor phosphorous levels)

(No reported resistance)

40

What are the preferred treatments for chronic HBV invection?

- Tenofovir and entecavir preferred for initial treatment

- Combo therapy for HIV/HBV coinfection, ts with drug resistance, and with decompensated cirrhosis

(e.g. Tenofovir + Lamivudine)

41

What are the endpoints of therapy in HIV negative pts treated for chronic HBV

- HBeAg, seroconversion

- Elimination of detectable virus

- ALT < 0.5 ULN

42

What is Hep C?

- Genetic material

- How many "genotypes"

- Integrates into human genome (Y/N)

- Transmission

- Progression of disease

Genetic material: RNA

How many "genotypes": 6

DOES NOT integrate into human genome

Transmission:

- Blood exposure

- Sex

- Occupational

- Peri-natal

Progression of disease:

- Slow progression to liver fibrosis and cirrhosis

- Accelerated by HIV and alcohol use

43

How was HCV previously treated? Side effects?

One regimen with a complex algorithm:

- Pegylated IFN (injected once weekly with many side effects, such as depression and fatigue)

- Ribavirin (weight-based dosing 2x daily with side effects such as anemia, rash, etc.)

44

Targets for direct acting antivirals (HCV)?

- NS3/4 protease inhibitors (translation and polyprotein processing)

- NS5B polymerase inhibitors (nucleosides, non-nucleosides) to inhibit RNA replication

(- Receptor binding and endocytosis)

(- Transport and release)

45

What drugs can be used to treat HCV? Drug classes for each?

- Telaprevir (NS3/4A protease inhibitor)

- Boceprevir (NS3/4A protease inhibitor)

- Sofosbuvir (NS 5B "nucleotide' polymerase inhibitor)

- Simeprevir (NS 3/4 protease inhibitor, GT 1 only)

- Ledipasvir/sofosbuvir (Harvoni) (NS 5A replication complex inhibitor/NS 5B)

- Ombitasvir/paritparevir/r, dasabuvir (Viekira) (NS 5a, PI/r, NS5B non-nucleoside polymerase)

46

Therapy for chronic Hepatitis C?

Old: Pegylated IFN + ribavirin + protease inhibitor

New: oral protease inhibitor therapies

47

Therapy for acute Hepatitis C results in what?

Possible reduction in the frequency of chronic hepatitis

48

Treatment for advanced liver disease (cirrhotic) pts has been shown to do what?

Inhibit the development of HCC (hepatocellular carcinoma?) and improve survival

49

What is the most common serotype of HCV in the US?

Genotype I

50

What is the timeline for current treatment of chronic Hep C?

Oral therapies with direct acting agents from 12-24 weeks according to the genotype (1-4) of the virus and presence/absence of cirrhosis

51

What is Imiquimod?

Immune response modulator useful for topical treatment of genital warts and several other skin diseases (incl basal cell and actinic keratoses)

- TLR7 agonist

52

What is fomivirsen?

Antisense oligonucleotide approved for treatment of CMV retinitis when other therapies have failed

53

Characteristics of Telaprevir?

- Class:

- Mechanism:

- Route:

- Adverse effects:

- Indications:

- Class: NS3/4A protease inhibitor

- Mechanism: serine protease inhibitor

- Route: Oral

- Adverse effects: rash, pruritis, anemia, nausea and diarrhea

- Indications: HCV infection in combination with IFN and ribavirin

54

Characteristics of Boceprevir?

- Class:

- Mechanism:

- Route:

- Adverse effects:

- Indications:

- Class: NS3/4A protease inhibitor

- Mechanism: Serine protease inhibitor

- Route: Oral

- Adverse effects: Anemia, dysgeusia, N, V, D. May increase risk of myopathy in pts on statins

- Indications: HCV infection in combination with IFN and ribavirin

55

Characteristics of Sofosbuvir?

- Mechanism:

- Route:

- Adverse effects:

- Indications:

- Mechanism: NS 5B "nucleotide" polymerase inhibitor

- Route: Oral (1 pill daily)

- Adverse effects: well-tolerated

Indications: approved for use for several genotypes:

- GT 1 or 4: 12 weeks with IFN/RBV (or alternatively 24 wks with RBV for GT 1)

- GT 2: 12 wks with RBV

- GT3: 24 wks with RBV

56

Characteristics of Simeprevir?

- Class:

- Route:

- Adverse effects:

- Indications:

- Class: NS 3/4 protease inhibitor

- Route: oral (1 pill daily)

- Adverse effects: well tolerated, photosensitivity, drug-drug interactions with efavirenze, ritonavir/cobi

- Indications: GT 1 only! (12 wks with extended IFN/RBV with baseline resistance testing before); use with sofosbuvir for 12 wks if no cirrhosis or 24 wks with cirrhosis (no ribavirin, no interferon)

57

Characteristics of Ombitasvir/paritaprevir/r, dasabuvir (Viekira)?

- Class:

- Used for:

- Adverse effects:

- Dosing schedule:

- Class: NS 5A, PI/r, NS 5B non-nucleoside polymerase

- Used for: used with RBV for GTI (except in GT 1B without cirrhosis in which case RBV is not needed)

- Adverse effects: well tolerated, multiple drug-drug interactions

- Dosing schedule: 3 pills in the morning, 1 in evening + RBV if needed

58

Characteristics of Ledipasivr/sofosbuvir (Harvoni)

- First ___ regimen approved

- Class:

- Uses:

- Adverse side effects:

- Dosing schedule:

- First IFN and RBV free regimen approved

- Class: NS 5A replication complex inhibitor/NS 5B

- Uses: Approved for GT 1 only (12 wks with 94-99% cure rates!)

- Adverse side effects: well-tolerated; may interact with efavirenz, cobi or ritonavir to elevate TDF levels

- Dosing schedule: co-formulated, one pill once daily

59

Case 1:

66 y.o. male with COPD presents with a 12 hr history of fever, cough, and myalgias. Local surveillance indicates that both influenza A/H3N2 and influenza B isolates are circulating. A rapid test for influenza is positive. Which one of the following oral medications would be an appropriate treatment choice?

A. Oseltamivir

B. Amantadine

C. Ribavirin

D. Rimantadine

Case 1:

66 y.o. male with COPD presents with a 12 hr history of fever, cough, and myalgias. Local surveillance indicates that both influenza A/H3N2 and influenza B isolates are circulating. A rapid test for influenza is positive. Which one of the following oral medications would be an appropriate treatment choice?

A. Oseltamivir

B. Amantadine

C. Ribavirin

D. Rimantadine

60

Case 2:

A 6 month old boy with congenital heart disease presents with severe bronchiolitis requiring hospitalization for respiratory support during an RSV epidemic. A rapid test for RSV is positive. Which of the following is the most appropriate approach to therapy?

A. Inhaled zanamivir

B. Intravenous zanamivir

C. Inhaled ribavirin

D. Intravenous ribavirin

Case 2: 

A 6 month old boy with congenital heart disease presents with severe bronchiolitis requiring hospitalization for respiratory support during an RSV epidemic. A rapid test for RSV is positive. Which of the following is the most appropriate approach to therapy? 

A. Inhaled zanamivir 

B. Intravenous zanamivir 

C. Inhaled ribavirin 

D. Intravenous ribavirin

61

Case 3:

A healthy 23 year old female presents with diffuse, painful genital ulcerations. Primary HSV2 infection is diagnosed. One year later she reports that lesions reappear each month. Which of the following agents is NOT indicated for suppression of her recurrences?

A. Acyclovir

B. Famciclovir

C. Ganciclovir

D. Valacyclovir

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Case 3: 

A healthy 23 year old female presents with diffuse, painful genital ulcerations. Primary HSV2 infection is diagnosed. One year later she reports that lesions reappear each month. Which of the following agents is NOT indicated for suppression of her recurrences?

A. Acyclovir 

B. Famciclovir

C. Ganciclovir 

D. Valacyclovir

62

Case 4:

A healthy 16 y.o. presents with varicella. Lesions started 18 hours ago. His 7 y.o. sister had varicella three weeks earlier. Which of the following statements is TRUE?

A. Therapy is not indicated because there is no effective therapy.

B. Therapy is not indicated because it is too late.

C. Therapy is available and may provide benefit.

D. Therapy is available but it is too toxic to use for treatment of varicella in a healthy host.

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Case 4:

A healthy 16 y.o. presents with varicella. Lesions started 18 hours ago. His 7 y.o. sister had varicella three weeks earlier. Which of the following statements is TRUE?

A. Therapy is not indicated because there is no effective therapy. 

B. Therapy is not indicated because it is too late. 

C. Therapy is available and may provide benefit.

D. Therapy is available but it is too toxic to use for treatment of varicella in a healthy host.

63

Case 5:

A previously healthy 80 year-old presents with painful vesicular lesions in the ophthalmic distribution of the fifth cranial nerve of 24 hours duration; ocular involvement is apparent. HZ is diagnosed. Which one of the following is the most appropriate approach to management? 

A. Symptomatic treatment

B. IV Acyclovir therapy

C. Ganciclovir therapy

D. Famciclovir therapy

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Case 5: 

A previously healthy 80 year-old presents with painful vesicular lesions in the ophthalmic distribution of the fifth cranial nerve of 24 hours duration; ocular involvement is apparent. HZ is diagnosed. Which one of the following is the most appropriate approach to management? 

A. Symptomatic treatment

B. IV Acyclovir therapy 

C. Ganciclovir therapy 

D. Famciclovir therapy

64

Case 6:

A 40 year old male with advanced HIV infection (CD4 ct < 50) complains of loss of vision. Ophthalmoscopic exam reveals severe bilateral retinitis. The diagnosis of CMV retinitis is made. Which of the following is not effective and appropriate treatment?

A. Acyclovir

B. Cidofovir

C. Foscarnet

D. Ganciclovir

Q image thumb

Case 6: 

A 40 year old male with advanced HIV infection (CD4 ct < 50) complains of loss of vision. Ophthalmoscopic exam reveals severe bilateral retinitis. The diagnosis of CMV retinitis is made. Which of the following is not effective and appropriate treatment?

A. Acyclovir

B. Cidofovir

C. Foscarnet

D. Ganciclovir