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20 Cards in this Set
- Front
- Back
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Nucleoside vs Nucleotide
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Nucleotide has 1 Pi group
Nucleoside has no Pi group |
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What are the two mechanisms by which nucleoside and nucleotide analogues work?
What is their target? |
Competitive inhibition: competes with dTTp (for example)--deoxythymidine-triphosphate
Chain termination: once it's incorporated into growing DNA chain, natural dNTP cannot be added Target = viral reverse transcriptase |
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Acyclovir: uses
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(Guanine analogue)
HSV>VZV Poor bioavailability |
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Valacyclovir: uses
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(oral prodrug of acyclovir)
HSV>VZV 3.5x greater bioavail |
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Famciclovir: uses
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HSV/CSV
(HSV much more common than cytomegalovirus) |
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Ganciclovir: uses
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(NuecleoSIDE analogue)
CMV Low bioavail |
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Valganciclovir: uses
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oral prodrug of ganciclovir
CMV |
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Foscarnet: uses
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pyrophosphate analogue
CMV, acyclovir-resistant HSV and VZV IV only, BM supression (anemia) |
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How many drugs should be used against a patient infected with HIV?
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3 drugs active against HIV
start and stop all at once simple regimens = better adherence BEST REGIMEN IS ONE PATIENT WILL TAKE |
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What is the preferred initial therapy for HIV-1 infected patients?
Alternatives? |
Preferred: tenofovir + emtricitabine
(two nucleoside analogues needed for cornerstone of triple combn tx) Alternatives: abacavir + lamivudine zidovudine + lamivudine |
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Tenofivir: uses
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(NucleoTIDE analogue)
v. long 1/2-life (10-50 hrs) Renal excretion inc'd creatinine, proteinuria, dec'd bone density Use: M184V HIV, HBV/HIV coinfected pts |
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Lamivudine + Emtricitabine: uses
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Few side effects
Rapid resistance (M184V) Use: HIV, HBV/HIV |
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Effect of K65R mutation in HIV?
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Sensitizes virus to AZT
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Abacavir: uses
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Metab'd by Alcohol DH
Hypersensitivity rxn in 5% HIV (questionably less active with higher viral loads) |
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Zidovudine: uses
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BID administration
Excellent CNS penetration Important for prevention of mother to child transmission (IV available) |
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Non-nucleoside reverse transcriptase inhibitors: uses
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Potent inhibitors of HIV-1, NOT HIV-2:
Efavirenz Nevirapine Etravirine |
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Efavirenz: class, uses
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Non-nucleoside reverse transcriptase inhibitor
CNS/psych syx in 50% pts DO NOT GIVE IN FIRST TRIMESTER OF PREGNANCY Rash in 27% part of Atripla tx---preferred for tx naive pts |
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Tenofovir + Emtricitabine + Efavirenz
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Tenofovir: nucleotide analogue
Emtricitbaine: ... Efavirnez: NNRTI 1 pill once a day Preferred regiment for tx naive pts!! |
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Nevirapine: class, uses
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NNRTI for HIV
used with Zidovudine, Lamivudine as alternative to atripla (Tenof, Emtric, Efavirenz) Induces p450 metabolism |
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Etravirine: class, uses
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2nd Gneeration NNRTI
BID admin INduces some p450 enzymes Resistance requires mulrtiple NNRTI mutations (Y181C is KEY MUTATION) |
