Unit 4 Viruses and Antiviral Medication Flashcards
1
Q
respiratory syncytial virus (rsv)
A
- incubation: 3-5 days
- enveloped
- transmission: large droplets, invades conjuntiva and nasopharynx
- ss RNA neg
- causes lower resp. tract infection, esp. in young children
- tx: ribavirin, vaccine failed, prophylaxis with respigam or synagis
2
Q
herpes simplex virus (hsv)
A
- incubation: 2-12 days, avg is 4
- dsDNA, enveloped
- transmission: skin to skin contact
- primary: may be silent, gingivostomatitis, herpatic whitlow, karatitis (eye), encephalitis
- can establish latency in neural ganglia
- reactivation of hsv 1 and 2 can be symptomatic or asymptomatic, but is most commonly asymptomatic
- reactivation can begin with tingling sensation followed by blister
- tx: acyclvir/valacyclovir/penciclovir, docosonol, gangcyclovir, c section for women with active lesions, no vaccine
3
Q
varicella zoster virus (vzv)
A
- dsDNA, enveloped
- incubation: 10 - 21 days
- transmission: close contact or respiratory
- primary infection= chicken pox acute systemic infection
- can establish latency in neural ganglia- shingles
- tx: acyclovir at high dose, gancyclovir
- vaccine: live attenuated, do not give to pregnant or immunocomrompised pts
4
Q
cytomegalovirus (cmv)
A
- dsDNA, enveloped
- incubation: 2 weeks to 2 months, asymptomatic in health people
- transmission: bodily fluids, birth
- can establish latency within monocytes and lymphocytes
- reactivation is associated with pneumonia, colitis, & retinitis
- tx: cidofavir, foscarnet, gancyclovir, no vaccine
- IgG present if had infection previously
- IgM present if current active infection
5
Q
influenza virus
A
- neg ssRNA (8 pieces), enveloped, RdRp, H and N structure, A, B, C types
- incubation: 1-3 days
- transmission: enters mucus membranes, aerosolized droplets, respiratory
- it is safe to administer inactivated flu vaccine to pregnant pts
- tx: amantiadine/rimantadine, oseltamivir, zanamivir, peramivir
6
Q
ebola virus
A
- enveloped neg ssRNA, VP40 budding structure, VP24 budding structure & defense, VP35= RdRp
- incubation: 2-21 days
- transmission: mucus membrane contact with an infected person
- severe infection associated with: diarrhea, 5-10L fluid loss/day, DIC
- tx: no approved tx, some in trials
7
Q
pneumocystis jiroveci
A
-tx with pantamidine
8
Q
acyclovir/vancyclovir/penciclovir
A
- MOA: phosphorylated by viral thymidine kinase- inhibits viral DNA
- pharmacokinetics: [A] topical, oral, IV (bioavailability greater in VAL/PEN, A=15-30%, VAL/PEN= 80%), P has renal excretion
- spectrum: HSV1, HSV2 (and VZV* at higher doses)
- adverse: MINOR TOXICITIES (high levls with valacyclovir may inc. risk of CNS/renal side effects)
- preferentially targets viral DNA polymerase
9
Q
palivizumab
A
- monoclonal antibody
- can be used to protect high risk infants from RSV
10
Q
amantidine/rimantidine
A
- targets the viral uncoating stage of influenza life style
- spectrum: INFLUENZA A
- A*- eliminated renally
- R*- eliminated hepatically
11
Q
docosanol (OTC)
A
- MOA: inhibits fusion between plasma membrane and HSV envelope
- pharmacokinetics: TOPICALLY applied 5x daily
- spectrum: HSV1 labialis
- adverse: well tolerated
12
Q
ganciclovir/valganciclovir
A
- MOA: phosphrylated by viral thymidine kinase to active form that inhibits viral DNA polymerase
- pharmacokinetics: poor oral absorption (good with val), distributes to CNS, renal excretion
- spectrum: HSV, VXV, CMV, SIGHT-THREATENING CMV retinitis
- adverse: BONE MARROW DEPRESSION, CNS
13
Q
cidofovir
A
- MOA: NUCLEOTIDE ANALOG, phosphorylated to active form by host kinases, inhibits viral DNA polymerase
- pharmacokinetics: long intracellular half life, given IV weekly/biweekly
- spectrum: many DNA viruses, CMV INFECTIONS (if resistant to ganciclovir/foscarnet)
- adverse: NEPHROTOXICITY (dec by probenecid use), rash in HIV pts
14
Q
foscarnet
A
- MOA: pyrophosphate analog (NO ACTIVATION STEP), inhibits viral DNA/RNA polymerase and RT
- pharmacokinetics: poor oral bioavailability, requires continuous infusion
- spectrum: CMV INFECTIONS (Gan resistant), acyclovir resistant HSV infections, HIV (second line)
- adverse: RENAL IMPAIRMENT, severe n/v electrolyte imbalance (esp. HYPOCALCEMIA)
15
Q
ribavirin
A
- MOA: triphosphorylated to active form, inhibits IMP dehydrogenase, inhibits viral RdRp, NUCLEOSIDE ANALOG
- pharmacokinetics: aerosol administration, well-absorbed ORALLY, long intracellular half life
- spectrum: RSV* (inh), hep C (oral) (w/ interferon)
- adverse: LOW AEROSOL TOXICITY, teratogen, systemic toxicity includes ANEMIA, bone marrow depression
