Summarize HIV prophylaxis and treatment regimens, including PREP, CYP450 inducers, treatment failure criteria, and second-line regimens.

Here is a summary of the information from your notes:

Step 1: HIV Prophylaxis and Treatment Regimens

• PREP (Pre-Exposure Prophylaxis):
  • $\text{TDF} + \text{FTC}$
  • $\text{TDF} + \text{3TC}$
• CYP450 Inducers:
  • Phenytoin
  • Carbamazepine
  • Rifampicin
  • Phenobarbital
• Treatment Failure Criteria:
  • Viral load $> 1000$ copies/$\text{mL}$
  • $\text{CD4}$ cell count $< 200$ cells/$\text{mm}^3$
  • Rule out poor adherence.
• Recommended 2nd Line Regimens:
  • $\text{AZT} + \text{3TC} + \text{DTG}$
  • $\text{AZT} + \text{3TC} + \text{DRV/r}$
  • $\text{TDF} + \text{3TC} + \text{DRV/r}$
  • $\text{TAF} + \text{FTC} + \text{DRV/r}$
• Alternative 2nd Line Regimens:
  • $\text{AZ