Switching from Descovy to Biktarvy After HIV Seroconversion
Yes, a patient taking Descovy (emtricitabine/tenofovir alafenamide) for pre-exposure prophylaxis who becomes HIV positive can be safely switched to Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide) without problems, provided that resistance testing is performed first. 1
Rationale for Switching to Biktarvy
Biktarvy is a recommended initial regimen for HIV treatment according to current guidelines:
- Biktarvy is listed as a "Generally Recommended Initial Regimen" with an evidence rating of AIa 1
- It contains bictegravir (an integrase strand transfer inhibitor) plus the same components found in Descovy (emtricitabine and tenofovir alafenamide)
- The patient is already taking two of the three components in Biktarvy (through Descovy)
Important Steps Before Switching
Before switching from Descovy to Biktarvy, the following steps should be taken:
Perform resistance testing: Genotypic testing for reverse transcriptase and protease resistance mutations is recommended prior to treatment initiation (evidence rating AIIa) 1
Laboratory evaluation: Conduct baseline laboratory tests including:
- CD4 cell count
- Plasma HIV-1 RNA level
- Hepatitis B and C serologies
- Complete metabolic panel
- Estimated creatinine clearance
- Complete blood count
- Sexually transmitted infection screening 1
Start treatment promptly: ART should be initiated as soon as possible after diagnosis 2
Benefits of Biktarvy
Biktarvy offers several advantages for a newly diagnosed HIV patient:
- High efficacy: Demonstrated virologic suppression in >94% of treatment-naïve patients 3
- High genetic barrier to resistance: Bictegravir has an improved resistance profile compared to earlier integrase inhibitors 4
- Convenient single-tablet regimen: Once-daily dosing promotes adherence 5
- Well-tolerated: Low discontinuation rates due to adverse events (only 2% through 96 weeks) 6
- No HLA-B*5701 testing required: Unlike abacavir-containing regimens 5
Monitoring After Switch
After switching to Biktarvy, monitoring should include:
- HIV RNA level every 4-6 weeks until virus is undetectable 1
- Once suppressed, monitor HIV RNA every 3 months for the first year, then at least every 6 months thereafter 1
- Check viral load 1 month after switching regimens to ensure virologic suppression is maintained (evidence rating BIII) 1
Potential Concerns and Contraindications
- Renal function: Biktarvy is not recommended in patients with estimated creatinine clearance below 30 mL/min 7
- Hepatic impairment: Not recommended for patients with severe hepatic impairment (Child-Pugh Class C) 7
- Drug interactions: Review all medications for potential interactions, particularly rifamycin drugs which are contraindicated 1
Common Side Effects
The most common adverse reactions with Biktarvy (occurring in ≥5% of patients) include:
- Diarrhea (3-6%)
- Nausea (3-6%)
- Headache (4-5%) 7
Most adverse events associated with Biktarvy are Grade 1 (mild) and rarely lead to discontinuation 7.
In conclusion, switching from Descovy to Biktarvy after HIV seroconversion is an appropriate and recommended strategy, provided that resistance testing is performed and no contraindications exist.