Antivirals Flashcards
what is the Mechanism of action of :
Glecaprevir and pibrentasvir
- Glecaprevir block protein NS3 / 4A protease, while pibrentasvir block NS5A
- This inhibits protease enzymes and prevents hepatitis C viral RNA replication.
Glecaprevir
blocks the protein NS3 / 4A protease
Pibrentasvir
works by blocking NS5A in HCV
Remdesivir
RNA polymerase inhibitor
Disrupts the production of viral RNA, preventing multiplication of SARS-CoV-2
Ribavirin side effect?
-Haemolytic anaemia.
-Teratogenicity.
-Minor issues with liver and renal function, but is uncommon.
(Dose adjustment is required in AKI)
When to offer HNIG in addition to hep A vaccine as PEP?
Any Contacts with:
-Chronic liver disease.
-pre-existing chronic hepatitis B or C
- >60 years old
-Immunosuppressed including HIV with CD4<200
T/F: Pregnant and breastfeeding women Should receive HNIG and vaccination for HAV PEP ?
F
should be managed the same as non-pregnant
contacts
what is the exclusion period for hepatitis A infected pt from childcare, preschool, school and work?
7 days after the onset of jaundice (if present) or 2 weeks from the onset of illness if there is no jaundice.
How to eradicate liver hypnozoite ?
primaquine :
- P. vivax requires 30 mg daily (0.5 mg/kg) for 14 days
- P. ovale does 15mg daily for 14 days to
HIV-2 is innately resistant to:
-NNRTIs e.g efavirenz, rilpivirine
- Fusion inhibitors e.g. enfuvirtide
-Some PIs:
atazanavir, amprenavir, nelfinavir
first line in HIV 2 with NRTI Backbone?
INSTI or Lopinavir /r
indications of VZIG as PEP in pregnancy (mum and neonate)?
1- For mums who are unable to take oral antivirals( hyperemesis , AKI, malabsorption )
2-for susceptible neonates exposed
within one week of delivery (in utero or post-delivery).
HIV resistance :
K65R
2- High level resistance to tenofovir (TDF/TAF) and abacavir (ABC)
——–
3- intermediately reduced susceptibility to emtricitabine (FTC) and lamivudine (3TC)
—————–
4- Increased susceptibility to zidovudine (ZDV)
HIV resistance :
L74V/I
Abacavir (ABC)
HIV resistance :
M184V/I
1- Selected by emtricitabine (FTC) or lamivudine (3TC) and significantly reduces susceptibility to them >100-fold
2- causes low level resistance to abacavir (ABC)
3- Conversely increases susceptibility to tenofovir (TDF/TAF) and zidovudine (ZDV)
HIV resistance :
T215Y/F
1- Zidovudine (ZDV)
2- Reduced susceptibility to abacavir (ABC) and tenofovir (TDF/TAF) in conjunction with other mutations
HIV resistance :
Y115F
Abacavir (ABC) and tenofovir (TDF/TAF)
What is the UL97 mutations?
Mutation in CMV UL97 kinase gene are a major mechanism of viral resistance to two anti-CMV drugs:
1- ganciclovir (GCV)
2- maribavir (MBV).
T/F: Rilpivirine should not be co-administered with rifampicin or rifabutin
T
HIV Resistance profile :
L100I
K101P/E/H
M230L
Nevirapine (NVP), efavirenz (EFV), etravirine (ETR) and rilpivirine (RPV)
HIV Resistance profile :
K103N/S
Nevirapine (NVP) and efavirenz (EFV)
HIV Resistance profile :
Y181C/I/V
Nevirapine (NVP), etravirine (ETR) and rilpivirine (RPV)
what is the commonest brain MRI finding of Progressive Multifocal Leukoencephalopathy /JC ? and HIV Encephalopathy.
PML : white matter lesion with no contrast enhancement
HIV encephalopathy :no white matter lesions but there is significant atrophy.
What is Progressive outer retinal necrosis ? and how to treat ?
It is a rapidly progressive viral retinitis, most often due to VZV, that involves the deepest layers (“outer” layers) of the retina and in HIV-positive patients with CD4+ < 100/mm3
Tx: very poor prognosis.
IV Ganciclovir +foscarnet plus intravitreal Ganciclovir.
Must be differentiated from Acute retinal necrosis most commonly occurs due to VZV ( rarely : EBV but occurs in pt with higher CD4 - Tx: aciclovir /valaciclovir
What are the negative sense ssRNA viruses ?
1-Orthommyxoviridae
2-Paramyxoviridae
3- Rhabdovirus
4-Filovirus
5- Bunyavirus
