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Microbiology ` microbiology—aNtimicrobials Microbiology ` microbiology—aNtimicrobials SEcTioN ii 201

Antiviral therapy
HIV ANTIVIRAL OTHER ANTIVIRAL
ENTRY
THERAPY
ATTACHMENT
Maraviroc – REVERSE Receptor
TRANSCRIPTASE binding
PENETRATION
Enfuvirtide – Uncoatingg
NRTIs Endo-
Abacavir (ABC) cytosis
Didanosine (ddI)
Emtricitabine (FTC)
Reverse – Lamivudine (3TC)
transcription Stavudine (d4T)
DNA Tenofovir (TDF) NUCLEIC ACID
integration Zidovudine (ZDV, SYNTHESIS
INTEGRASE formerly AZT)
NNRTIs Replication Guanosine analogs
Dolutegravir – ranscription Delavirdine – Acyclovir, etc (HSV, VZV)
Ganciclovir (CMV)
Elvitegravir Efavirenz Prottein
Raltegravir Nevirapine synthesist Viral DNA polymerase
Bictegravir inhibitors
Virion Cidofovir HSV*,
assembly Foscarnet CMV
Translation Guanine nucleotide
PROTEASE synthesis
HUMAN
Proteolytic CD4+ T CELL CELL Ribavirin (RSV, HCV)
processing
Atazanavir *Acyclovir-resistant
Darunavir
Fosamprenavir
Indinavir – RELEASE OF PROGENY VIRUS
Lopinavir ackaging
Ritonavir and assembly
Saquinavir Neuraminidase inhibitors
Budding Oseltamivir
– Influenza A, B
Releeasasee Zanamivir

Oseltamivir, zanamivir
mecHaNism Inhibit influenza neuraminidase Ž  release of progeny virus.
cliNical Use Treatment and prevention of influenza A and B. Beginning therapy within 48 hours of symptom
onset may shorten duration of illness.

Acyclovir, famciclovir, valacyclovir

mecHaNism Guanosine analogs. Monophosphorylated by HSV/VZV thymidine kinase and not phosphorylated
in uninfected cells Ž few adverse effects. Triphosphate formed by cellular enzymes. Preferentially
inhibit viral DNA polymerase by chain termination.
cliNical Use HSV and VZV. Weak activity against EBV. No activity against CMV. Used for HSV-
induced mucocutaneous and genital lesions as well as for encephalitis. Prophylaxis in
immunocompromised patients. No effect on latent forms of HSV and VZV. Valacyclovir, a
prodrug of acyclovir, has better oral bioavailability.
For herpes zoster, use famciclovir.

aDVerse eFFects Obstructive crystalline nephropathy and acute kidney injury if not adequately hydrated.
mecHaNism oF resistaNce Mutated viral thymidine kinase.

FAS1_2019_03-Microbiology.indd 201 11/14/19 12:22 PM