Term
| Why don't we have better drugs against viruses? |
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Definition
| Viruses work within our own cells = hard to kill |
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Term
| What are the two common types of human herpesviruses? |
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Definition
1. Herpes simples virus (HSV) - sores of mouth, face, genitals
2. Varicella zoster virus (VZV) - varicella & zoster |
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Term
| Where do the herpes viruses sequester? |
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Definition
| In the nerves and nerve ganglia |
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Term
What drugs are commonly used against herpesvirus?
Administration? |
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Definition
Acyclovir (Zovirax) - TOP, PO, IV
Famciclovir (Famvir) - PO
Valacyclovir (Valtrex) - PO |
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Term
What are anti-herpes Rxs mechanism of action?
ADRs? |
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Definition
| Inhibit viral replication, few ADRs, given prophylactically c recurrent attacks |
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Term
| What is Epstien-Barr virus? |
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Definition
*herpes virus
*up to 95% infected during childhood
*asymptomatic or mild viral s/s
*in unexposed adults can cause mono |
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Term
| What are the manifestations of mononucleosis? |
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Definition
| *Sore throat, fever, fatigue, lymphadenophathy (esp. post. nodes) - lasting 1 wk or more |
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Term
| What is Cytomegalovirus (CMV)? What site does it commonly affect? |
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Definition
*Very common "infection" - actually herpesvirus
*sequesters in dormant form
*very serious in HIV/transplant pts.
*Affects the eyes = CMV retinitis |
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Term
| What does viral hepatitis cause? Why? |
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Definition
*Inflammation of the liver
*Elevation of enzymes ALT & AST
*Lysing of hepatic cells release ALT & AST into blood |
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Term
| What two viral types cause chronic hepatitis? Can they be vaccinated against? |
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Definition
*Hep B = yes vaccine
*Hep C = no vaccine |
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Term
| What drugs are used for viral hepatitis? Administration? ADRs? |
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Definition
*INTERFERON A (for Hep C) = cytokine compound c important role in immunity.
*Give SQ (self inject 1/wk)
*ADR: flu-like sx, depression
*only works with certain viral genotypes
*RIVAVIRIN = used in conjunction c Int.A
*PO
*Long course = 24-48wks)
*ADR = severe anemias, teratogenic (Cat.x)
*LAMIVUDINE = suppress viral replication in Hep B
*PO = Qdaily
*Few ADR |
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Term
| What is HIV virus mechanism of action? |
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Definition
| Creates immunodeficiency by killing "helper" CD4 T cells |
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Term
| What are the current CDC guidelines defining AIDS? |
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Definition
*HIV infection AND
*CD4 T cell count <200 OR
*AIDS defining illness |
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Term
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Definition
| *Contain single strand RNA which must be transcribed to DNA using intrinsic enzyme reverse transcriptase |
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Term
| When does HIV replicate the quickest? What does this mean for treatment? |
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Definition
*During initial onset = no immune response yet
*Tx during onset can reduce # of long-living HIV infected cells |
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Term
| What does frequent mutations of a disease causing organism lead to? |
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Definition
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Term
| What types of drugs are used to treat HIV? |
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Definition
*Immune stimulants
*Abx
*Antifungals
*Antiviral (mainstay) = multi-drug tx |
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Term
| What are the three classes of HIV antivirals? |
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Definition
1. Reverse transcriptase inhibitors (2 types)
2. Protease inhibitors
3. HIV fusion inhibitors |
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Term
| What is the Reverse transcriptase inhibitor prototype? What does it do? ADRs? |
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Definition
*Zidovudine (Retrovir aka ZDV or AZT)
*Intrudes on RNA to DNA conversion = prevents further growth of new viral DNA strand
*Decreases viral load, increases CD4 T cell counts, delays onset of symp, reduce severity of symp.
*ADR = severe anemia, neutropenia |
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Term
| What are the ADRs of protease inhibitors? |
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Definition
| *drug induced diabetes, elevated lipids, fat maldistribution, bone mineral density |
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Term
| What is HIV fusion inhibitors mechanism of action? Administration? ADR? Cost? |
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Definition
*Enfuvirtide aka T-20
*blocks entry into T cell
*SQ
*Injection reaction
*Very expensive $20,000/yr |
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