Recommended Initial Antiretroviral Therapy (ART) Regimen
For most treatment-naïve adults with HIV, start with an integrase strand transfer inhibitor (INSTI)-based regimen: either bictegravir/tenofovir alafenamide/emtricitabine (BIC/TAF/FTC) or dolutegravir plus tenofovir alafenamide/emtricitabine (DTG + TAF/FTC) as first-line therapy 1.
Initial Regimen Selection
Preferred 3-Drug Regimens
The following INSTI-based regimens are recommended as initial therapy 1:
- Bictegravir/tenofovir alafenamide/emtricitabine (BIC/TAF/FTC) - single tablet regimen
- Dolutegravir + tenofovir alafenamide/emtricitabine (DTG + TAF/FTC)
- Dolutegravir + tenofovir disoproxil fumarate/emtricitabine (DTG + TDF/FTC)
- Dolutegravir + tenofovir disoproxil fumarate/lamivudine (DTG + TDF/3TC)
Preferred 2-Drug Regimen
Dolutegravir/lamivudine (DTG/3TC) is the single recommended 2-drug regimen for initial ART 1, but has important restrictions:
Do NOT use DTG/3TC if:
- Lamivudine resistance detected on genotyping
- HIV RNA ≥500,000 copies/mL
- Hepatitis B co-infection present
- During pregnancy (limited data)
- CD4+ count <200/μL (limited data)
Critical point: DTG/3TC should not be initiated without baseline laboratory results confirming the above criteria are met 1.
Special Populations
Pregnancy
For pregnant persons or those planning pregnancy, use dolutegravir with TAF/FTC (or TDF/XTC if TAF/FTC unavailable) 1. This recommendation is based on high antiviral efficacy and low rates of adverse birth outcomes. BIC/TAF/FTC is an alternative, and persons already on this regimen who become pregnant should continue if tolerated and effective 1.
If dolutegravir is not an option, use tenofovir/emtricitabine plus darunavir 600 mg twice daily with ritonavir 100 mg 1.
Suspected INSTI Resistance
When INSTI resistance is suspected before resistance testing results return (particularly with prior long-acting cabotegravir PrEP exposure), initiate boosted darunavir-containing regimens 1. Modify to INSTI or NNRTI-based therapy once resistance testing excludes resistance to these classes.
PrEP Failure
For persons acquiring HIV while on tenofovir/emtricitabine PrEP, dolutegravir or bictegravir combined with tenofovir/emtricitabine can be started before resistance testing, but results should inform which regimen is continued 1.
Dosing Schedule
All recommended first-line regimens are once-daily dosing:
- BIC/TAF/FTC: single tablet once daily
- DTG + TAF/FTC: dolutegravir 50 mg + one TAF/FTC tablet once daily
- DTG/3TC: single tablet once daily
Exception: Darunavir-based regimens require twice-daily dosing (darunavir 600 mg + ritonavir 100 mg twice daily) 1.
Monitoring Plan
Viral Load Monitoring
Measure viral load within 4-8 weeks after starting ART, then every 3 months during the first 2 years 2. After 2 years of consistent suppression, extend monitoring to every 6 months 2.
The IAS-USA guideline specifically recommends:
- Within 6 weeks of ART initiation
- After 12 weeks, then every 3 months if suppressed
- After 12 months of suppression, then every 6 months 2
Rationale: First-line INSTI regimens achieve near-universal viral suppression (99.3% at 48 weeks) in persons remaining on therapy 2, making frequent early monitoring critical to identify the rare cases of non-suppression.
CD4 Count Monitoring
Measure CD4 count at baseline, then every 3-6 months initially 2. Once CD4 count is >250 cells/mm³ for 1 year and viral load is consistently suppressed, CD4 monitoring can be discontinued 2.
Evidence note: Meta-analysis of 20,297 persons found confirmed CD4 decline occurred in only 0.4% of persons with sustained viral suppression 2, supporting less frequent monitoring once stable.
Other Laboratory Monitoring
At baseline, obtain:
- Complete blood count
- Comprehensive metabolic panel (renal and hepatic function)
- Hepatitis B and C screening
- HIV genotype resistance testing (if not already done)
- Pregnancy test (if applicable)
Routine hematologic monitoring is not clinically useful with contemporary first-line regimens 2. Phase 3 trials showed no evidence of hematologic toxicity from modern ART regimens 2.
Common Pitfalls to Avoid
Do not delay ART initiation waiting for extensive testing - Start ART as soon as possible, preferably at diagnosis, to reduce transmission and improve outcomes 1, 3
Do not use DTG/3TC without confirming eligibility criteria - This regimen requires specific laboratory confirmation before initiation 1
Do not continue ineffective monitoring - Once virally suppressed with CD4 >250 for 1 year, extensive CD4 monitoring adds no clinical value 2
Do not overlook drug-drug interactions - Particularly important with rifampin for tuberculosis treatment; most INSTI regimens have significant interactions requiring regimen modification 1
Do not use rilpivirine, doravirine, or elvitegravir/cobicistat with rifampin - These have prohibitive drug-drug interactions 1