Anti-Virals Flashcards
MOA of Acyclovir/Cidofovir?
inhibition of viral DNA polymerase
MOA of Amantadine/Rimantadine?
Inhibition of viral entry or uncoating
MOA of Ribavirin?
Inhibition of viral nucleic acid synthesis
MOA of Oseltamavir/Zanamivir?
Inhibition of release of influenza virus from infected cells
How is acyclovir metabolized?
Viral cells (not host) transform acyclovir to its active triphosphate form
How is Amantadine metabolized?
Systemic elimination unchanged by glomerular filtration and tubular secretion
How is cidofovir activated?
Metabolized via pyrimidine nucleoside monophosphate kinase to mono- & thendiphosphate analogs and finally to the monophosphate-choline
How is cidofovir metabolized?
Systemic elimination unchanged by glomerular filtration and tubular secretion
How is Oseltamavir activated?
Hepatically metabolized to the carboxylate active form of the drug
How is Oseltamavir metabolized?
Systemic elimination by glomerular filtration and tubular secretion
How is Ribavirin metabolized?
Undergoes non-CYP metabolism in nucleated cells with systemic elimination ofdrug and products in the urine
How is Rimantadine metabolized?
Extensive hepatic metabolism with renal elimination of drug & metabolites
How is Zanamivir metabolized?
Renally eliminated unchanged
AEs of acyclovir?
Headache, nausea, neurotoxicity (confusion, seizures)
How to give acyclovir correctly
Maintain hydration to prevent renal precipitationUse cautiously in renal impairment or with reno-toxic drugs
When is amantadine contraindicated?
Contraindicated in narrow angle glaucoma and with breastfeeding
BBW of Cidofovir?
Renal impairment/toxicity
As of Oseltamavir?
Minimal adverse effectsPotential for fatal neuropsychiatric adverse effects in flu patients; serious skin reaction reported rarely
BBW of Ribavirin?
hemolytic anemia & M/F teratogenicity
Added AE of Valacyclovir?
Thrombocytopenia
AEs of Zanamivir?
Headache, throat/tonsil pain, cough, viral infection
Contraindications of Zanamivir?
pulmonary disease – fatal bronchospasm! especially in asthma patients
T or F. Amantadine and Rimantadine are good for Flu A AND B
F. Just A
When does treatment need to be initiated for effective treatment of Flu?
48 hours maximum
If a patient had influenza A and Amantadine was used, what should the physician consider?
-eliminated unchanged in kidneys (renal failure)-accumulation would exacerbate neurologic toxicity
If you give zanamivir to an asthmatic, what else should be given?
pre-treatment with albuterol inhaler
AEs of amantadine?
-behavioral changes (seizures, agitation)
How does amantadine cause behavioral changes?
alteration of dopamine neurotransmission
Behavioral changes from amantadine are more common in which patients?
-seizure disorders-renal insufficiency-advanced age
What concurrent drugs can increase risk of behavioral changes from amantadine?
-antihistamines-anticholinergic drugs-HCTZ-Bactrim
Acute Amantadine overdose can cause what?
clinical manifestations of anticholinergic activity (GI stasis, urinary retention, dry mouth)
Common AE of Amantadine? Very important
livedo reticularis (progression to ilceration possible, but usually resolves with drug withdrawal)
