Antiretroviral Drugs- (NRTI's) Flashcards
(51 cards)
Current anti-retroviral drugs for treatment of HIV are:
1) nucleoside reverse transcriptase inhibitors (NRTIs)
2) Nucleotide inhibitors
3) non-nucleoside reverse transcriptase inhibitors (NNRTIs)
4) Protease inhibitors
5) Fusion inhibitors
7) Integrase inhibitors
Why should monotherapy of anti-retrovirals by avoided?
Increased risk of resistance
What is HAART?
Combination therapy (Highly active anti-retroviral therapy)
What must be monitored in HAART?
viral load and CD4 cell count in case of development of resistance
In HIV diagnosis, you should look for what?
Abs against virus, not virus species
What are Nuclease Transcriptase Inhibitors (NRTI)?
Nucleoside analogs that inhibit viral reverse trancriptase (RT) and also cause chain termination during viral DNA synthesis.
NRTI’s MOA?
Require intra-cytoplasmic activation by phosphorylation by cellular enzymes including TK to the triphosphates
Name the 6Nuclease Transcriptase Inhibitors (NRTI):
1) Zidovudine
2) Didanosine
3) Lamuvudine (SULFUR RING, HEP B ALSO)
4) Zalcitabine
5) Stavudine
6) Abacavir
Zidovudine is a…
deoxythymidine analog that contains an azido group on the 3’ carbon of the dideoxyribose pentose sugar
Ziduvudine bioavailability?
Good oral bio, tissue dist and cns distribution (60-65% in cerebrospinal fluid compared to plasma) (35% plasma protein bound)
ZIduvudine undergoes what kindof elimination?
hepatic glucuroniation and renal elimination (glom filtration and tubular secretion)
Ziduvudine has increased toxicity due to?
Renal and hepatic insufficiency
What drug reduces the rate of clinical disease progression and prolongs survival in HIV infected patients?
Ziduvudine (AZT)
What drug reduces viral transmission of HIV to the fetus in pregnant women and what dosage forms?
1) Oral AZT during pregnancy
2) IV during labor
3) syrup to the new born
Ziduvudine resistance may be due to?
mutations in the pol gene, withdrawal of AZT may permit reversion to susceptible wild type strain
Adverse effects of Ziduvudine:
myelosuppression- causing anemia, neutropenia, GI intolerance, headache, and insomnia, but may resolve.
AZT co-admin with other myelosuppressive drugs may cause what?
increased hematoxicity
What other myelosuppresive therapies when co-admin’d with AZT may cause hematoxicity?
1) Ganciclovir
2) Ribavirin
3) other cytotoxic agents
Didanosine is what analog?
a deoxyadenosine analog
How should didanosine be taken and why?
It should be taken on an empty stomach bc it is unstable at a low pH
Resistance to didanosine is due to?
RT mutation at 74 and may confer cross resistance to abacavir, lamivudine, and zalcitabine.
Adverse effects of didanosine?
1) Dose dependent pancreatitis
Didanosine is contraindicated in?
cases of alcoholism and hypertriglyceridemia due to the AE pancreatitis
Patients on high dose therapy of didanosine may require what monitoring?
periodic retinal examination
