Antimicrobial Chemotherapy - Antivirals Flashcards
How do almost all anti-herpes drugs work? (Except foscarnet and cidofovir)
Nucleoside analogue - they interfere with nucleic acid synthesis
What does aciclovir work against?
HSV and VZV
What do famciclovir and valaciclovir work against?
HSV and shingles
What do ganciclovir and valganciclovir work against?
CMV - cytomegalovirus
What does foscarnet treat?
HSV, VZV and CMV when they are resistant to nucleoside analogue
What does cidofovir treat?
CMV retinitis
What must occur for aciclovir to work?
It must be converted to the active form by an enzyme coded for by the virus genome
How is aciclovir delivered?
IV for severe infection (HSV AND VZV)
For HSV - orally or topically
What are famciclovir and valaciclovir like? And how are they are administered?
They are like aciclovir but have a better bio availability - orally
What is ganciclovir used for? (Specific )
Treat life or sight threatening infection in the immunocompromised
What is VaLganciclovir a pro-drug off and how is it taken instead?
Pro drug off ganciclovir and an oral alternative for some CMV Situations (e.g treatment of prophylaxis)
when would cidofovir be used ?
when other anti-viral drugs are inappropriate.
What kind of drug is the anti-HIV drug zidovudine? (also known as AZT or ZDV)
nucleoside analogue
Tell us a bit about zidovudine and how it works.
Combination therapy - new normal practice for treatment. The different drugs act on different stages of replication.
This drug interferes with the action of reverse transcriptase.
It slows the virus down.
How does the anti- HIV Nevirapine work? and what is it used in combination with?
it is an non-nucleuosidic reverse transcriptase inhibitor. It is often used with zidovudine.
Which anti-herpes drugs cause bone marrow toxicity so must be closely monitored blood count ?
ganciclovir and valganciclovir
When may aciclovir cause neurological toxicity?
When renal impairment occurs
How is foscarnet toxic?
It is highly nephrotoxic
What are some side effects of zidovudine?
anaemia and neutropenia. It is significantly toxic.
Is nevirapine toxic?
highly toxic
Name a protease inhibitor anti-HIV drug.
Saquinavir
What can saquinavir be used with?
zidovudine
Is saquinavir toxic?
It is highly toxic
how does interferon a work?
it is a part of the host’s immune response that has been genetically altered.
what does interferon a work on?
selected chronic hep b and hep c infections.
give some details on interferon a.
They become pegylated - attach to PEG.
They have slow excretion and treatment frequency is reduced to once a week.
They are supplied subcutaneously .
why are interferon a not used much?
serious side effects
low response rate
high cost of treatment
What is interferon a combined with for a common treatment for chronic hep c?
ribeflavin
what is ribavavin used for?
chronic hep C. or serious RSV infection.
how is ribavavin used with and how is it applied?
orally - daily.
used with interferon a
what is the name a nucleoside analogue treatment that is used to treat HIV and Hep B?
lamivudine.
How is lamivudine administered?
orally
Name two drugs that can be used to treat influenza a and b ?
Zanamavir and Oseltamivir.
When should the two drugs used to treat influenza a and b be used?
within 48 hours of onset of symptoms and also post - exposure prophylaxis
Name a nucleoside analogue that treats the occasional severe RSV infections and chronic Hep C
Ribavarin
How is ribavarin administered?
Inhalation - quite hard as it is a fine spray and must reach the site of infection.
What does ribavarin reduce mortality in?
Lassa Fever
