Antivirals Flashcards
6 classes of antiretrovirals
NRTI
NNRTI
Protease inhibitors
Entry inhibitors
Fusion inhibitors
Integrase inhibitors
Common ending to NRTIs
-dine (not all)
Common ending to protease inhibitors
-navir
ONLY NRTI that doesn’t have to be phosphorylated and why
Tenofovir
It is a nucleoTide
NRTI mechanism of action
Inhibit diester bond formation
—> viral DNA premature termination
Main side effect of all NRTIs
Mitochondrial toxicity
Lactic acidosis
Lamivudine
NRTI
Also used for hepatitis B
Peripheral neuropathy
One of the less toxic
Tenofovir uses
HIV
Hepatitis B
Zidovudine
NRTI
Pregnancy and breastfeeding
Infant prophylaxis
Myelosuppression
Lipodystrophy
Stavudine
NRTI
Children and adults
Peripheral neuropathy
Lipodystrophy
Didanosine
NRTI
Pancreatitis dose-dependent
Peripheral neuropathy
Abacavir
NRTI
Hypersensitivity: HLA-B57:01
—> type IV, delayed rash
NNRTI MOA
Binds allosterically —> inhibits reverse transcriptase
—> halt DNA polymerase
NNRTI 3 main side effects
Hepatic failure - life-threatening within 6 weeks
CNS: hallucinations, dizzy, ache, insomnia
Teratogenic
NNRTIs (inhibit/induce) P450.
Induce ++++
Nevirapine
NNRTI
Infants and children
Rash
Efavirenz
NNRTI
Only in combination!
Very effective and tolerable except psychiatric effects
NNRTIs are more effective versus HIV 1 or 2?
HIV 1
NRTIs are more effective versus HIV 1 or 2?
Both <3
Protease inhibitors are more effective versus HIV 1 or 2?
Both <3
What gene are proteases encoded by? Why are they needed?
POL
To create virions into mature versions
How do strains of HIV obtain resistance?
POL mutations
Protease inhibitors main side effects
METABOLIC
- Insulin resistance —>hyperglu —> diabetes
- Dyslipidemia
- Lipodystrophy
Inhibit P450
Indinavir
Protease inhibitor
Nephrolithiasis within days - give H2O
Least protein-bound
Ritonavir
Protease inhibitor
BOOSTS other drug duration by inhibiting P450
GI effects
Atazanavir
Protease inhibitor
Darunavir
Protease inhibitor
FAST
Fosamprenavir
Protease inhibitor
Long half-life
Tipranavir
Protease inhibitor
ONLY if resistant to other meds, can cause hepatotoxicity or intracranial bleeding
Given with ritonavir
Lopinavir
Protease inhibitor
Pediatric with ritonavir
Saquinavir
Protease inhibitor
Rarely used
Which medication is used to boost effect duration of protease inhibitors?
Colbistat
Also ritonavir
Which drug is contraindicated with protease inhibitors?
Rifampin!!!
(Induces P450)
Maraviroc
Entry inhibitor
Binds to CCR5, can’t bind to gp120
Gene in charge of structure proteins in HIV
Env gene —> gp41, gp120
Enfuvirtide
Fusion inhibitor in HIV
Inhibits gp41
ONLY HIV 1
Subcutaneous
Raltegravir
Integrase inhibitor in HIV
Prevents mRNA formation after DNA
Well tolerated, rare rhabdomyolysis
Both HIV 1 and 2
Threshold for HBV treatment
> = 10,000 copies/mL AND high ALT
3 possible drugs for HBV
Entecavir
Tenofovir TDF
IFN
IFN can only be given if cirrhosis is (compensated/decompensated)
Compensated
What is important about pegylated interferons?
Longer half-life
Steady concentrations
1 weekly dose
IFN why are they not recomended?
Flu-like symptoms
Neurotoxicity
Myelosuppression
Lupus
Tinnitus
Retinopathy
Etc.
AND EXPENSIVE
IFN uses
Hepatitis B and C
Cancers
Multiple sclerosis (beta)
Chronic granulomatous disease (gamma)
Treatment of choice for decompensated cirrhosis by hepatitis virus
Nucleoside analogues
Which is the cheapest anti-hepatitis? Why isn’t it given as monotherapy?
Lamivudine
High resistance, 71% mutation
First line treatment for HBV
ENTECAVIR
TDF —> tenofovir
TDF is prodrug, cleaved by esterases
Entecavir side effects
Nausea, fatigue, headache
Lactic acidosis
Hepatomegaly
Entecavir
Guanosine analogue
FIRST line for HBV
Adefovir
Adenosine monophosphate analogue for HBV
Inhibits viral DNA polymerase
Why is entecavir preferred over adefovir?
Adefovir —> resistance and NEPHROTOXICITY
Lamivudine
Nucleoside analogue for HBV
High resistance, add tenofovir or adefovir
HCV genotypes and most common one
6 total
1 is the most common, followed by 3
NS5B enzyme
RNA-polymerase inhibitors for HCV
In ALL GENOTYPES
Ex. Sobosfuvir
NS3/4A
Protease inhibitors for HCV
Inhibit P450
Ex. Simeprevir for genotype 1 or 4
Ribavirin
Nucleoside analogue
Inhibits RNA polymerase of HCV
Given with PEG-IFN
Ribavirin main side effects (2)
Hemolytic anemia dose-dependent 20%
Teratogenic category X
First-line treatment for HCV
Ribavirin + PEG-IFN
HSV first line treatment
Acyclovir
Acyclovir
Guanosine nucleoside for HSV
1. +P by VIRAL thymidine-kinase
2. +2p by cellular enzymes
Triphosphate —| DNA synthesis
Acyclovir indications
HSV encephalitis
Neonatal
Acyclovir side effects
Interstitial nephritis
Crystalline nephropathy
Can be avoided by drinking H2O
Ganciclovir
Guanosine nucleoside for HSV
1. +P by VIRAL thymidine-kinase
2. +2p by cellular enzymes
Triphosphate —| DNA polymerase
Valganciclovir
Ganciclovir prodrug
More bioavailability
(Val)ganciclovir side effect
Myelosuppression —> possible leukemia
Oseltamivir
Sialic acid analogue
Inhibits neuraminidases in influenza
—> no virion release
GI effects
First line of treatment for influenza
Oseltamivir
Zanamivir
Neuraminidase inhibitor
Why is oseltamivir preferred over zanamivir?
What other difference is there between both?
Zanamivir can cause severe side effects if there is a pre-existent airway disease.
Oseltamivir: oral
Zanamivir: inhaled
First line treatment for CMV
(Val)ganciclovir
Safest antiretroviral
Lamivudine
NRTIs = La Zebra Anda TENsa, Es Season De VIH
Lamivudine
Zidovudine
Abacavir
Tenofovir
Emcitrabine
Stavudine
Didanosine