Non-HIV Viral Infections

Question 1

What are the components of a virus?

Answer 1

Virion, Capsid, and Envelope

Question 2

What are the 5 stages of the viral replication cycle?

Answer 2

1. Attachment
2. Penetration
3. Synthesis
4. Assembly
5. Release

Question 3

What are the challenges of antiviral therapy?

Answer 3

There is a rapid mutation rate of viruses, it is difficult to suppress viral replication without harming the host cells, and there is a narrow spectrum of activity for antivirals

Question 4

Herpes simplex virus

Answer 4

family of DNA viruses that cause blister-like lesions on the skin, genitals, and mucous membranes; usually acquired by direct physical contact w/infected individual or from mother to baby

Question 5

What are the different types of HSV?

Answer 5

HSV 1
HSV 2
CMV
VZV
EBV
HSV 6

Question 6

acyclovir (Zovirax)

Answer 6

antiviral for HSV; nucleoside analog
USE: most effective against HSV 1 & 2
MOA: prevents viral DNA replication by affecting 2 viral enzymes
AE: rash, pruritis, neurotoxicity @ high IV doses, and nephrotoxicity
Contraindications: use caution in pt’s w/CKD and increase fluid intake to prevent crystalluria

Question 7

Influenza

Answer 7

viral infection characterized by sore throat, sneezing, coughing, fever, chills, fatigue, etc; transmitted via airborne/hand-to-hand contact

Question 8

Hemagglutinin

Answer 8

an enzyme that facilitates the attachment of the influenza virus to host cells

Question 9

Neuraminidase

Answer 9

an enzyme that assists the influenza virus in escaping the host cell

Question 10

oseltamivir (Tamiflu)

Answer 10

neuraminidase inhibitor used to treat active influenza infections; must be given within 48 hours of onset of symptoms; can decrease the disease duration from 7 to 5 days

Question 11

amantidine (Symmetrel)

Answer 11

antiviral for influenza; viral replication inhibitor
USE: active influenza infection
MOA: precise action unknown; may inhibit viral uncoiling or affect assembly
AE: 33% experience CNS effects (insomnia, dizziness, nervousness, confusion, and decreased concentration)
Precautions: can have toxic effects on pt’s w/CKD & older adults; DO NOT GIVE W/ALCOHOL - CAN INCREASE CNS EFFECTS; use contraception to avoid pregnancy during therapy

Question 12

Hepatitis A

Answer 12

caused by RNA virus; transmitted through oral-fecal route; does not develop into chronic form; vaccine available

Question 13

Hepatitis B

Answer 13

caused by DNA virus; transmitted through blood/body fluids; can progress to cirrhosis and liver cancer; vaccine available

Question 14

Hepatitis C

Answer 14

transmitted through blood/body fluids; 40-50% connected w/HIV; can progress to chronic hepatitis and cirrhosis; NO vaccine available but 12 weeks of therapy can cure it

Question 15

tenofovir (Viread)

Answer 15

antiviral; reverse transcriptase inhibitor
USE: HIV infection, combined HBV/HIV infections, & chronic HBV in adults & children 12 y/o and older
MOA: inhibits viral DNA synthesis by inhibiting reverse transcriptase
AE: abd pain, n/v, insomnia, pruritis, dizziness, pyrexia, worsened kidney disease, and decrease bone density
BLACK BOX WARNING: lactic acidosis, steatosis, hepatomegaly, acute exacerbations of disease if tx is abruptly stopped

Question 16

What is the treatment goal for someone with HBV?

Answer 16

sustained suppression of HBV DNA to prevent cirrhosis or cancer; can use antivirals or immunostimulants