Antiviral & Antifungal Drugs Flashcards
What are the targets of viruses? (3)
lipoprotein envelope
protein capsid
DNA or RNA core
What are the general approaches to attack viruses? (3)
Vaccination
Chemotherapy
Stimulation of host resistance mechanisms
Viral drugs work by acting on different phases of viral attachment to the host. Name them. (5)
Phase 1: Attachment/penetration into host cell
Phase 2:Uncoating of the virus
Phase 3:Synthesis of viral DNA
Phase 4: Protein synthesis by host cell
Phase 5,6: Assembly and release of virus
What phase does gamma globulin (IgG) work upon?
What is its mechanism of action?
Phase 1
It blocks the attachment of the virus to the host.
What phase does amantadine (Symmetrel) work upon?
What is its mechanism of action?
Phase II: uncoating
It targets M2 protein and inhibits the acidification of the virus.
What 2 drugs are given orally for prevention and treatment of early infection of influenza A virus?
amantadine (Symmetrel)
rimantadine (Flumadine)
What drugs are neuraminidase inhibitors? (2)
Oseltamivir (Tamiflu)
Zanamivir (Relenza)
What phase does Oseltamivir (Tamiflu) and Zanamivir (Relenza) which are neuramidase inhibitors work?
What is the mechanism of action?
Phase 1,6 drug: attachment and assembly/release
Inhibit neurominidase (sialidase) of influenza A and B.
What drugs catalyze the cleavage of a sugar residue, preventing the spread of the virus in the respiratory tract?
neuramidase inhibitors
Oseltamivir (Tamiflu), Zanamivir (Relenza)
What drug blocks viron release?
Tamiflu
What drug requires herpes viral thymidine kinase for activation and is given for a variety of herpes infections?
Acyclovir (Zovirax)
What phase does acyclovir (Zovirax) work upon?
What is its mechanism of action?
Synthesis of DNA/RNA
It competitively inhibits viral DNA polymerase.
What drug is effective against herpes simplex virus strains that are deficient in thymidine kinase?
Foscarnet (Foscavir)
What drug is used for the treatment of cytomegalovirus retinitis in pts with AIDS?
Foscarnet (Foscavir)
What drug is used for the treatment of acyclovir-resistant mucocutaneous herpes simplex?
Foscarnet (Foscavir)
What drug is used as an aerosol for severe lower respiratory tract infections due to respiratory syncytial virus?
Ribavirin (Virazole, Rebetol)
What drug is used in conjunction with interferon alpha for the treatment of chronic hepatitis C?
Ribavirin (Virazole, Rebetol)
What are the sites of action for HIV drugs? (2)
reverse transcriptase inhibitors (nucleoside and non-nucleoside)
protease inhibitors
What was the was the first drug licensed for use in HIV treatment?
zidovudine (AZT)
What HIV drug forms this combination?
zidovudine + lamivudine
Combivir
What HIV drug forms this combination?
abacavir + lamivudine + zidovudine
Trizivir
What drug interferes with the entry of HIV-1 into cells?
Fuzeon (enfuvirtide)
What HIV drug inhibits the fusion of viral and cellular membranes?
Fuzeon (enfuvirtide)
What antiviral drugs work on the attachment and penetration (Phase 1) site? (3)
Gamma globulin
Fuzeon
Tamiflu
What are the sites of action for antifungal drugs? (4)
Damage cell membrane
Block cell division
Inhibit nucleic acid synthesis
Inhibit cell wall biosynthesis
What antifungal drugs damage the cell membrane as their site of action? (2)
Amphotericin B
Azoles
What antifungal drug blocks cell division?
Griseofulvin
What antifungal drug inhibits nucleic acid synthesis?
5-Flucytosine
What antifungal drug inhibits cell wall biosynthesis?
Caspofungin
What are 2 key points to remember about the antifungal drug Ampohtericin B?
It is a broad spectrum agent.
It is a polyene antibiotic.
What antifungal drug:
has both hydrophilic and hydrophobic regions
binds to sterols in the fungal membrane
prefers ergosterol over cholesterol
Amphotericin B
What is the premier antifungal drug used to treat the most severe systemic mycoses (e.g. blastomycosis, histoplasmosis, cryptococcal meningitis)?
Amphotericin B
Note: This is the gold standard.
What antifungal drug is also known as “amphoterrible”? Why?
Amphotericin B because it causes renal toxicity (80%)!!
What antifungal drug is:
similar to amphotericin B
used topically/orally for candida
NYstatin
Note: NY= NY state
What antifungal drug binds to microtubules to prevent mitotic spindle formation?
Griseofulvin
What antifungal drug:
NARROW spectrum
treats athlete’s foot
can cause GI upset and headache
otherwise minimal side effects
Griseofulvin
What are synthetic antifungal agents called?
Azoles
What antifungal agent inhibits ergosterol synthesis, leading to a damaged and leaky membrane?
Azoles
What are key points to know about fluconazole (Diflucan)? (5)
Broad spectrum
Treats most candida species
Single oral dose
Treats fungal meningitis
Reaches high concentration in the CNS
What antifungal drug:
is a derivative of Diflucan
primary treatment for invasive aspergillosis
Voriconazole
What are key points to remember for the antifungal drug Itraconazole (Sporanox)? (3)
Broad spectrum
Hydrophobic
Low gastric pH for absorption
What new antifungal drug prevents Candida and Aspergillus infections in immunocomparomised patients?
Posaconazole (Noxafil)
What antifungal drug treats dandruff?
Ketoconazole
