HIV prevention strategies + Drug interactions Flashcards
(34 cards)
What is PrEP used in conjunction with other HIV prevention strategies? (3)
- Safer sex
- UTI screening and treatment
- Using sterile needles
What lab evaluation should be checked for PrEp
- HIV test
- Hep C (HCV) antibody (Q12 months)
- STIs: gonorrhea, chlamydia, syphilis
Clinical evaluation:
- HIV symptoms
- PrEP adherence
- indication for PrEP
- use of other prevention strategies, syndemic conditions (2+ diseases affecting each other)
Can PrEP be taken indefinitely?
Yes
- However, only dispense 3 month supply at a time to ensure they get testing q3months
What PrEP options do we have available (2)
Which is preferred
- TDF 300mg/ FTC 200mg daily:
- ODB covered
- TDF formulation is generally PREFERRED over TAF - TAF 25mg/ FTC 200mg daily:
- NOT covered by ODB
- Only approved for: MSM
- Trans-women
- Heterosexual men (biological men)
**Any bioloigcal women can’t take TAF
What is the on-demand PrEP dosing? Who is it for?
For MSM, Transgender women (off-label)
- 2-24 hours before sex: double dose
- 24 hours after 1st dose: 1 dose
- 48 hours after 1st dose: 1 dose
What is time to optimal drug concentration level for the following population on tenofovir
MSM
Non-pregnant women
Pregnant women
MSM
- 7 DAYS to reach max intracellular concentration of tenofovir in anal tissues
Non-pregnant women
- Up to 20 DAYS for tenofovir and/or FTC
Pregnant women
- At least 20 DAYS
* DHHS guidelines recommend continued use of condoms until PrEP is taken for 20+ days in pregnancy or post-partum
What is the likely cause for PrEP failure?
What is a good recommendation to make
When patient is exposed to a drug-resistant HIV strain
Thus, we recommend the use of condoms while on PrEP
Cabotegravir for PrEP
Superior/inferior to TDF/FTC?
Dosing?
In a non-inferiority study, Q2monthly Cabotegravir was shown to be SUPERIOR to DAILY TDF/FTC for prep
- Study was done in Cis-men and trans-women (who have sex with men)
Dose: Single-agent Cabotegravir (CAB) 3mL injection into gluteal region
- 1st injection, 2nd @1 month then Q2months onward
Lenacapavir for PrEP
Dosing?
Trial efficacy?
DOSING Lenacapavir (LEN) for PrEP:
Day 1: First injection + 2 PO tabs
Day 2: 2 PO tabs
Injections Q6months!!!
Trial:
- 0 HIV transmissions with Lenacapavir used for PrEP (in Cisgender women)
For PEP, what does the exposure significance and transmission risk depend on? (4)
- Type of body fluid involved
- Type of injury or exposure that occurred
- Size of the inoculum
- Attributes of the source + patient (i.e STI)
What is the % chance of getting HIV, Hep B, Hep C transmission from a needle stick injury
HIV: 0.23%
Hep B: 6-30%
Hep C: 3-10%
What baseline testing do you need to do for the individual source? (3)
HIV antigen/antibody (4th gen test)
Hep B (HBsAG)
Hep C (HCV Ab)
What baseline testing does the EXPOSED individual have to do? (6)
HIV antigen/antibody (4th gen test),
Hep B (HBsAg, anti-HBs, anti-HBc)
Hep C
- If starting on HIV PEP: CBC, SCr, ALT
- Pregnancy test
- If sexual exposure: STI testing
What is the cut-off start for PEP and duration of therapy
WHEN to start:
- within 72 hours of exposure
HOW LONG to be on PEP
- 4 weeks, if tolerated
What is the 1st line regimen for PEP for needle stick injury (occupational injury)
TDF 300mg / FTC 200mg + RALTEGRAVIR 400mg
What is the 1st line regimen for PEP for sexual assault exposure
TDF 300mg / FTC 200mg + DOLUTEGRAVIR 400mg
In the absence of any intervention, what is the risk of HIV transmission from mother to baby
25%
What choice of therapy is given to mother to prevent neonatal transmission
Dose?
When should be given?
When should you stop?
Give even if Resistance?
Zidovudine (NRTI)
Dose
- 2mg/kg IV loading dose 1 hour
- 1mg/kg/hr continuous infusion
When
- Give at the beginning of labour
- 3 hours before C-section
Stop
- when umbilical cord is clamped
Resistance
- still give medication
When should a women with HIV have a c-section (2)
- Women with high viral load (>1000 copies/mL)
- Unknown HIV VL during birth:
get C-section at 38 weeks (not the usual 39 weeks)
How long should newborn babies receive HIV medication for?
Should they breastfeed or get formula
2-6 weeks after birth
Formula
What is the rationale of giving IV Zidovudine regardless of Viral load count during labour
BC found that 9% of women with undetectable HIV VL had detectable HIV VL at delivery
When should the baby receive prophylaxis for HIV
Within 6 hours of delivery
Differentiate between low risk vs high risk of children getting HIV
Low
- Mother got ARV during pregnancy (antepartum) with sustained virologic suppression (<50 copies/mL) near delivery
- and no concerns with ARV adherence
High
- mother did not get ARV antepartum
- only got ARV intrapartum
- had detectable viral loads near delivery
- have acute/primary HIV infection
Treatment options for HIV prophylaxis for babies who are
Low risk
High risk
Low risk
- Zidovudine (NRTI) PO for 4 weeks
High risk
- Zidovudine PO + Lamivudine (3TC) + RalteGRAVIR (INSTI) or Nevirapine (NNRTI) PO for 6 weeks
