Table 1.
Frequency of Samples with High or Intermediate or Low Resistance Levels among 58 Patients Treated at the Moment of Genotypic Resistance Testa,b
| |
|
Levels of resistance |
||
|---|---|---|---|---|
| Antiretrovirals used in clinical practice | Samples from experienced patients (N) | High/Intermediate n (%/N) | Potential low/Low n (%/N) | Susceptible n (%/N) |
| NRTIsc | 57 | 26 (45.6) | 6 (10.5) | 25 (43.9) |
| 3TC | 45 | 24 (42.1) | 2 (3.05) | 31 (54.4) |
| AZT | 37 | 17 (29.8) | 6 (10.5) | 34 (59.6) |
| D4T | 27 | 17 (29.8) | 6 (10.5) | 34 (59.6) |
| DDI | 25 | 14 (24.6) | 8 (14.0) | 35 (61.4) |
| ABC | 16 | 15 (26.3) | 15 (26.3) | 27 (47.4) |
| FTC | 0 | 24 (42.1) | 2 (3.05) | 31 (54.4) |
| TDF | 0 | 5 (8.8) | 15 (26.3) | 37 (64.9) |
| NNRTIsd | 14 | 6 (42.9) | 2 (14.3) | 6 (42.3) |
| EFV | 14 | 6 (42.9) | 1 (7.1) | 7 (50.0) |
| NVP | 1 | 6 (42.9) | 2 (14.3) | 6 (42.3) |
| PIse | 46 | 21 (45.7) | 0 (0.0) | 25 (54.3) |
| SQV | 25 | 16 (34.8) | 3 (6.5) | 27 (58.7) |
| IDV | 24 | 13 (28.3) | 5 (10.9) | 28 (60.9) |
| NFV | 9 | 21 (45.7) | 0 (0.0) | 25 (54.3) |
| ATV | 0 | 13 (28.3) | 6 (13.0) | 27 (58.7) |
| DRV | 0 | 3 (6.5) | 10 (21.7) | 33 (71.7) |
| FAPV | 0 | 10 (21.7) | 9 (19.6) | 27 (58.7) |
| LPV | 0 | 8 (17.4) | 11 (23.9) | 27 (58.7) |
| TPV | 0 | 9 (19.6) | 5 (10.9) | 32 (69.6) |
The analysis was performed on 57 samples. The genotype results were interpreted for each drug using the Stanford algorithm 1.4.4. (http://hivdb.stanford.edu), for which levels of resistance are ranked as susceptible, potential low-level resistance, low-level resistance, intermediate resistance, and high-level resistance.
NRTIs, nucleoside reverse transcriptase inhibitors; 3TC, lamivudine; AZT, zidovudine; d4T, stavudine; DDI, didanosine; ABC, abacavir; FTC, emtricitabine; TDF, tenofovir. NNRTIs, non-NRTIs; EFV, efavirenz; NVP, nevirapine. PIs, protease inhibitors; SQV, saquinavir; IDV, indinavir; NFV, nelfinavir; ATV, atazanavir; DRV, darunavir; FAPV, fosamprenavir; LPV, lopinavir; TPV, tipranavir.
The level of resistance for each NRTI used in clinical practice was calculated on N = 57 samples from NRTI-experienced patients.
The level of resistance for each NNRTI used in clinical practice was calculated on N = 14 samples from NNRTI-experienced patients.
The level of resistance for each PI used in clinical practice was calculated on N = 46 samples from PI-experienced patients.