- Factors affecting adherence and drug exposure, including tolerability/toxicity issues, drug–drug interactions/food interactions, ARV potency, signiﬁcant renal/liver disease and mental health/drug dependency problems are evaluated.
- Resistance testing should be performed while on failing therapy or within 2-4 weeks of discontinuation.
- Past ART and resistance tests should be reviewed for archived mutations.
- Tropism testing should be performed if MVC is being considered.
- Intensification with an additional active ARV is not recommended.
- Once virological failure is confirmed and a resistance result available, the regimen should be changed as soon as possible to avoid accumulation of resistance mutations.
The choice of the new ART regimen will primarily depend on the results of resistance testing and the patient’s preference. Additional considerations include the results of tropism and HLA-B*5701 testing, DDIs/food interactions, co-morbidities and future therapy options. The goal of the new combination is to re-establish a VL <50 copies/mL.