Antiretrovirals Flashcards
How is Zidovudine administered?
Oral
Short acting; given 5X per day
What is the MOA for NRTIs?
Nucleoside analogue
Inserts itself into growing chain and inhibits viral reverse transcriptase leading to DNA termination
What is significant about the penetration of Zidovudine?
Good CNS penetration
What are the uses for Zidovudine?
Maintain CD4 count; lessen opportunistic infections
DOC:
HIV in Pregnancy (+ Lamivudine)
AIDS dementia
What are toxicities of Zidovudine?
- Lactic acidosis or hepatoxicity
- Myelosuppresion: neutropenia, anemia (caution when bone marrow compromised or using ganciclovir, ribavirin)
- HA, nausea, vomiting, insomnia
What are the uses of Tenofovir and Emtricitabine?
DOC:
HIV (given together)
What are the toxicities of Tenofovir and Emtricitabine?
- Flatulence
- Lactic acidosis or hepatoxicity
What drug should you not use with Tenofovir and Emtricitabine?
Do not use with Lamivudine as similar mechanism and resistance profiles
What are the uses of Lamivudine?
DOC:
- Co-infection of HIV and Hep B
- HIV in pregnancy (+ Zidovudine)
Monotherapy in HBV
What are the toxicities of Lamivudine?
- Lactic acidosis or hepatoxicity
- HA, fatigue, insomnia, GI
What drugs must you combine with Abacavir?
Lamivudine or Zidovudine
What are toxicities of Abacavir?
- Serious hypersensitivity (screen for HLA-B-5701 as if positive for this allele, has higher chance for SJS)
- Lactic acidosis or hepatoxicity
What are special considerations for Abacavir?
Screen for HLA-B-5701 as if positive for this allele, has higher chance for SJS
If hypersensitivity occurs, stop drug and do not restart it as it could be fatal
What is the MOA for NNRTIs?
Bind directly to inhibit viral reverse transcriptase and prevent conversion of RNA to DNA (no phosphorylation)
What are the uses for Efavirenz?
DOC:
Initial HIV treatment
What are toxicities of Efavirenz?
- Drug interactions – induces CYP3A4
- Decreases effectiveness of oral birth control and methadone
- Teratogenic!
What are contraindications to Efavirenz?
Pregnancy
What are the uses for Rilpivirine?
DOC:
Initial HIV therapy in pregnant patients
What are contraindications for Rilpivirine?
Patients with hepatitis co-infection as may increase liver enzymes
What is the MOA of all protease inhibitors?
Inhibit proteases which inhibits the production of smaller proteins and ultimately decreases viral loads as they cannot replicate
What are the drug reactions associated with protease inhibitors?
Protease inhibitors are metabolized by CYP3A4 and have interactions with drugs that induce CYP3A4 such as Rifampin and Rifabutin
What protease inhibitor is given with other protease inhibitors and why?
Ritonavir is often given in combination because it is a potent inhibitor of CYP3A4 which increases PI levels for lower dose/less frequent dosing
What should you not use with protease inhibitors and why?
Should not use St. John’s Wort as it increases the metabolism of protease inhibitors
Should not combine with statins as protease inhibitors already increase serum cholesterol
What are common toxicities associated with all protease inhibitors?
- Altered body fat distribution
- Insulin resistance
- Increase in serum cholesterol (do not combine with statins)
- Spontaneous bleeding
