Antivirals Flashcards
What are the primary antivirals used to treat Herpes?
Acyclovir (IV/PO/Topical)
Valacyclovir (PO)
Famciclovir (PO)
What is the mechanism of action of the antivirals for Herpes?
Inhibition of viral DNA polymerase
- activation by viral thymidine kinase (TK)
How should you dose Acyclovir?
Ideal Body Weight
Name a neuraminidase inhibitor that is commonly prescribed.
Oseltamivir (Tamiflu)
What is the mechanism of action of Osteltamivir (Tamiflu)
Viral neuraminidase inhibitor
- prevents further replication
How soon should Oseltamivir be started after the onset of symptoms?
Within 2 days
By how many days does Oseltamavir decrease the duration of Influenza?
About 1 day
What type of cells does HIV attack?
CD4+ T-Helper Cells
HIV disease phase that presents as a flu-like illness with lymphadenopathy and a rash in about 50% of patients. These symptoms may last several weeks.
Acute Seroconversion (Phase 1)
HIV disease phase with few or no signs and symptoms but CD4 T-Cell count is steadily declining. May last a few years to a decade or more.
Asymptomatic HIV (Phase 2)
HIV disease phase where the immune system is damaged enough for significant opportunistic infections to develop.
OR
CD4 T-Cell count is less than 200 cells per microliter.
AIDS (Phase 3)
What class of drugs are used to treat HIV?
Antiretroviral Therapy (ART)
Highly Active Antiretroviral Therapy (HAART)
When treating a patient for HIV, what should you always be checking for in terms of treatment?
Drug Interactions
What was the first anti-retroviral drug for HIV and when was it introduced?
Zidovudine (AZT)
1987
Nucleoside/Nucleotide Reverse Transcriptase Inhibitor
(NRTIs)
Abacavir
Tenofovir
Emtricitabine
Lamivudine
Zidovudine
A present HLA B*5701 gene may result in a hypersensitivity to what NRTI?
Abacavir (Ziagen)
How are most NRTIs dosed?
Renal Dosing
What two diseases can NRTIs currently be used for?
HIV
Hepatitis B
Non-nucleoside Reverse Transcriptase Inhibitors (NNRTIs)
“All have -vir in the middle of the name”
Efavirenz
Nevirapine
Etravirine
Rilpiverine
What NNRTI is considered a Pregnancy Category D drug?
Efavirenz
Protease Inhibitors
(HAARTs)
“end in -navir”
Atazanavir
Ritonavir
Lopinavir
Why are there a lot of drug interactions with protease inhibitors?
Strong CYP450 Inhibitors
Using normally undesirable potent inhibition of drug-metabolizing enzymes of Ritonavir to increase the concentrations and half lives of other Protease Inhibitors.
Boosting
What is the only protease inhibitor that is used without a booster?
Atazanavir
HIV medication that blocks the integration of proviral genes into human DNA and is the newest class of anti-retroviral therapy and is now recommended as part of the 1st line therapy. Have very minimal drug interactions.
“all have -tegr in the middle of their name”
Integrase Inhibitors
- Raltegravir
- Elvitegravir
- Dolutegravir
Inhibits CCR5 receptors on cell membranes and prevents the entry of HIV into the cell.
Maraviroc
(CCR5 Inhibitor)
Major adverse drug reaction of Maraviroc.
Hepatotoxicity
(Black Box Warning)
What enzyme metabolizes Maraviroc?
CYP450
Genetic testing is required for all patients prior to initiating therapy with Maraviroc, what must be positive to use this drug?
CCR5 Positive
Combination drug but in separate tablets and used to treat COVID-19.
Paxlovid
(Nirmatreivir + Ritonavir)
How many days does Paxlovid reduce the symptoms of COVID-19 by?
2 - 3 days
What is the mechanism of action of Paxlovid?
Protease inhibitor that blinds to enzyme to prevent replication
RNA polymerase inhibitor used to treat COVID-19 and Ebola. Can only be administered through IV.
Remdesivir
Oral medication that must be taken within 5 days of symptom onset and is used to treat COVID-19. Acts as a ribonucleoside analog for viral RNA polymerase increase mutations.
Malnupiravir
