dolutegravir + darunavir + ritonavir

The combination of dolutegravir (DTG) plus darunavir/ritonavir (DRV/r) represents a dual antiretroviral regimen that has gained attention for its high genetic barrier to HIV-1 resistance. This makes it particularly valuable for salvage therapy in treatment-experienced patients or as a simplification strategy for complex antiretroviral regimens. ## Pharmacology and Mechanism of Action This combination brings together two powerful antiretroviral drug classes: - **Dolutegravir**: An integrase strand transfer inhibitor (INSTI) that works by binding to the active site of HIV integrase and blocking the strand transfer step of retroviral DNA integration into the host cell genome. It has a mean EC50 value of 0.5 nM to 2.1 nM in peripheral blood mononuclear cells and MT-4 cells. - **Darunavir/ritonavir**: Darunavir is a protease inhibitor that prevents viral replication by binding to the active site of HIV protease. Ritonavir serves as a pharmacokinetic enhancer (booster) that increases darunavir concentrations by inhibiting its metabolism. ## Clinical Efficacy Studies have demonstrated the effectiveness of this combination: - In an Italian observational study involving 130 HIV-1-infected subjects followed for a median of 56 months, switching to DTG plus DRV/r proved effective for both salvage therapy and simplification of more complex regimens. - The proportion of subjects with undetectable viral load increased from 38.5% to 76.2% after treatment with this combination. - The D²EFT study showed that dolutegravir plus darunavir/ritonavir was superior to a standard-of-care boosted protease inhibitor regimen for second-line treatment of people experiencing failure of a first-line regimen containing a non-nucleoside reverse transcriptase inhibitor. ## Safety Profile The combination has demonstrated a favorable safety profile: - In the Italian study, only one subject discontinued due to liver enzyme elevation, while 90 out of 283 baseline laboratory alterations returned to normality by week 48. - The D²EFT study reported that treatment was well tolerated, with serious adverse events evenly distributed between study arms. - Common side effects associated with darunavir/ritonavir include diarrhea, nausea, vomiting, headache, rash, and abdominal pain. - Potential serious adverse effects include liver problems, severe skin rash, and allergic reactions, particularly in patients with a history of hepatitis B or C. ## Advantages of the Combination This dual regimen offers several benefits: 1. **High genetic barrier to resistance**: Both components have robust resistance profiles, making this combination particularly valuable for heavily treatment-experienced patients. 2. **Simplification**: The regimen allows for simplification of more complex antiretroviral combinations while maintaining virologic suppression. 3. **Metabolic profile**: Studies have shown that switching to DTG plus DRV/r can be accomplished without negative metabolic impacts. 4. **Once-daily dosing**: Both medications can be administered once daily, improving convenience and potentially enhancing adherence. The combination of dolutegravir plus darunavir/ritonavir represents an important treatment option for HIV-infected individuals, particularly those with treatment experience or resistance concerns.

Brand names

Prezista (darunavir)Norvir (ritonavir)Tivicay (dolutegravir)

Other names

DTG + DRV/rDTG plus DRV/r