antivirals Flashcards
effective against
HSV, HZV, flu A and B, RSV, hepatitis, HIV, CMV
acyclovir
lots of routes
3 moa: interfere with viral nucleic acid synthesis, its regulation, or both (DNA and RNA); prevent virus from binding to cells so virus cannot get into cells thus preventing replication; stimulates body’s immune system to kill virus
acyclovir - herpes
I: HSV1, HSV2, VZV
decrease symptom severity and freq of outbreaks, not a cure
used for initial and recurrent infection - may require multiple treatments
reduce viral shedding and decrease local S
decrease severity and duration of illness
disease can reoccur again, not a cure
SE: GI distress, renal impairment, seizures, ITP; IV form = tissue necrosis if IV not patent or use central line
oseltamivir
flu - mostly A but some B
moa: inhibit neuraminidases in influenza viruses
I: prophylaxis and active disease (48hr of s onset), mostly elderly and immunocompromised after KNOWN exposure, also swine flu
PO only
SE: n/v, seizures, renal impairment
ganciclovir
CMV (really only concern for AIDS, immunocompromised, transplants)
controls but doesn’t cure
moa: inhibit viral DNA polymerases resulting in chain termination
IV and PO (dont crush or split - irritate skin)
blackbox: hematologic toxicity (pancytopenia, thrombocytopenia), fertility impairment, fetal toxicity (brain defects), carcinogenesis (animals)
dont give with imipenem-cilastatin (seizure potential)
watch kidneys if given with other nephrotoxic drugs
so few antivirals
virus only replicates after entering cell, antiviral must enter cell to work
often done replicating by time s/s show
only work during cell replication
also kill healthy cells
non HIV
virus is parasitic microbe, no cell wall, insert own RNA/DNA into healthy cell
antivirals inhibit replications -> immune system destroys
herpes
genital: HSV1 = above waist; HSV2 = below waist
zoster: shingles, vaccine -> >50yr, lower rink and reduce severity of outbreaks
