TABLE 9.
Antiretroviral drug resistance mutations.
| Drug | Key mutations selected |
|---|---|
| 3TC or FTC | Selects for M184V, which compromises both 3TC and FTC and slightly impairs the activity of ABC but increases susceptibility to AZT and TDF. |
| TDF | Selects for K65R, which compromises TDF and ABC but increases susceptibility to AZT. Tenofovir disoproxil fumarate also selects for K70E, which causes low-level resistance to TDF, ABC and possibly 3TC/FTC. |
| ABC | Selects for L74V, which compromises ABC. May also select for K65R, which compromises TDF and ABC but increases susceptibility to AZT. Selects for Y115F, which decreases its susceptibility. |
| AZT | Selects for TAMs, which may ultimately compromise all NRTIs. |
| d4T | Selects for TAMs, which may ultimately compromise all NRTIs. |
| EFV or NVP | Selects for K103N, which causes high-level resistance to EFV and NVP. Also selects for Y181C and other NNRTI mutations, which cause resistance to EFV, NVP, RPV and ETR. |
| RPV | Selects for several mutations, including E138K, which compromise its susceptibility. |
| PIs | Multiple mutations are usually required before seeing a decrease in susceptibility, especially for LPV and DRV, and cross-resistance between the PIs is common. ATV selects for I50L, which causes high-level resistance to ATV but not to other PIs. |
| RAL | Selects for Q148H/K/R, Y143C and N155H, which cause resistance to RAL and, in certain combinations, to DTG too. |
| DTG | Very rarely selects resistance if InSTI-naive, provided that it is coupled with at least one other fully active drug. In patients with prior RAL exposure, mutations such as Q148H may cause decreased DTG susceptibility when combined with additional mutations. |
3TC, lamivudine; ABC, abacavir; ATV, Atazanavir; AZT, zidovudine; d4T, stavudine; EFV, efavirenz; ETR, etravirine; DTG, dolutegravir; FTC, emtricitabine; InSTI, integrase strand transfer inhibitor; LPV, lopinavir; NVP, nevirapine; PIs, protease inhibitors; RAL, raltegravir; RPV, rilpivirine; TAMs, thymidine analogue mutations; NRTIS, nucleoside reverse transcriptase inhibitors; NNRTI, non-nucleoside reverse transcriptase inhibitor; TDF, tenofovir disoproxil fumarate.