antivirals Flashcards
viral particles (virions) characteristics
- outer coating with protein spikes
- lipoprotein envelope
- inner proteins (specific to virus)
- nucleic acid core (RNA/DNA)
- coat/capsid
what is a virus
tiny microorganism that infects and replicates inside host cell
- uses host machinery to make proteins
- cannot replicate on its own
covid virus name
severe acute respiratory syndrome coronavirus 2 (SARS-CoV2)
covid disease name
coronavirus disease 2019 (covid 19)
- disease gives symptoms
problems of viral treatments
- viruses live inside host cells
- viral infections initially asymptomatic
what is the best response to a viral infection
healthy immune system
- immunocompromised patients have frequent viral infections
viruses controlled by antiviral therapy
- cytomegalovirus
- hepatitis viruses
- herpes virus
- HIV
- influenza viruses
- respiratory syncytial virus
what do antiretroviral drugs treat
treat HIV
what do antiviral drugs treat
viral infections
HIV
human immunodeficiency virus
- attack helper T cells
- long term leads to AIDs (lack of T cells)
- transmitted by fluids
- RNA –> DNA with reverse transcriptase
AIDs
helper T cells diminished and body likely to develop other infections
- opportunistic infections
- no symptoms until other infections show up
types of opportunistic infections from AIDs
- protozoal
- fungal
- viral
- bacterial
- opportunistic neoplasias (kaposi’s sarcoma)
antiretroviral types
- reverse transcriptase inhibitors
- protease inhibitors
- integrase inhibitors
reverse transcriptase inhibitors (RTI)
block activity of reverse transcriptase
RTI subclasses
- nucleoside RTI (nucleoside drug into chain)
- non-nucleoside RTI (drug binds to enzyme and stops it)
nucleoside RTI example
zidovudine (AZT: azidothymidine)
RTI adverse effects
bone marrow suppression (anemia and neutropenia)
protease inhibitors
inhibit protease enzyme which makes protein chains into functional proteins
protease inhibitors adverse effect
- hyperglycemia
- new/exacerbate diabetes
protease inhibitor example
ritonavir
ritonzavir interactions
- many drug-drug interactions
- CYP inhibitor (metabolism reduced)
integrase inhibitors
inhibits insertion of HIV DNA into t cell DNA
- HIV integrase strand transfer inhibitors (INSTIs)
what is HIV combination therapy called
highly active antiretroviral therapy (HAART)
why combination therapy?
hiv mutates often (mistakes in dna which cause drug resistance)
types of drug combinations
- 2 NRTIs = 1 NNRTI
- 2 NRTIs = 1 or 2 protease inhibitors
- BIKTARVY: integrase inhibitor + 2 NRTIs
pre exposure prophylaxis
HIV prevention for people at risk of being exposed
- daily drug regime
- 2 RTI combination
post exposure prophylaxis
drugs taken soon after possible HIV exposure to prevent possible infection
- start within 3 days
- lasts 28 days
- integrase inhibitor and 2 RTIs
most common influenza virus
influenza A (96%)
- H & N surface proteins
chronic hepatitis strains
B and C
herpesvirus group
varicella zoster virus
- chickenpox (varicella)
- shingles (herpes zoster)
herpes simplex virus
- HSV-1 (oral)
- HSV-2 (genital)
cytomegalovirus
drugs for influenza virus
neuraminidase inhibitors
- prevents release of virus from host cell
- can be used prophylactically
neuraminidase inhibitor example
oseltamivir (Tamiflu)
newer flu drug
baloxavir
- single dose
- equal effectiveness to oseltamivir
drugs for herpes virus (VZV & HSV)
DNA polymerase inhibitors
- stops viral DNA synthesis
- synthetic nucleosides
DNA polymerase example for HSV and VZV
acyclovir
- oral, topical, parenteral
drugs for herpesvirus (CMV)
DNA polymerase inhibitor
- Ganciclovir
- oral and parenteral
- surgically implanted ophthalmic form
CMV
- high risk in immunocomproised
- common in AIDs
- loss of vision
ribavirin
- synthetic nucleoside
- PO or nasal inhalation
- for RSV and hepatitis C
