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In specific circumstances, DRV/r + 3TC (lamivudine) regimens have been shown to maintain viral suppression in ART naïve patients without baseline resistance as well as patients with viral suppression. The most commonly studied regimens, LPV/r + 3TC and ATV/r + 3TC have been shown to be noninferior to 1 PI + 2 NRTI regimens in studies. However, some experts recommend a regimen of DRV/r + 3TC because it has a more favorable safety profile due to the reduced pill burden, higher efficacy, and better tolerance of DRV as compared to LPV or ATV.

Recommendations for treatment-naïve patients

DHHS:  DRV/r + 3TC is considered to be a reasonable option when regimens containing TDF, TAF, or ABC are either contraindicated or cannot be used, based on success with a regimen of LPV/r + 3TC, which is recommended by the DHHS as a "recommended regimen in certain clinical situations" when TDF, TAF, and ABC cannot be used. These regimens have achieved virologic suppression in ART-naïve individuals without baseline mutations as well as maintain virologic suppression in virally suppressed patients in studies[1]. Generally speaking, regimens containing DRV are recommended over those containing LPV/r, given that LPV/r is poorly tolerated.

IAS: 2-drug regimens have limitations and are only recommended in cases where they offer cost or toxicity advantages over 3-drug regimens. Another 1 PI + 1 NRTI regimen, LPV/r + 3TC (lamivudine) was found to be noninferior to LPV/r + 2 NRTIs in one study and can be considered as a possible regimen[2].

Recommendations for treatment-experienced patients

DHHS: In virally suppressed patients, the DHHS notes that switching to a regimen of a boosted PI plus 3TC may be considered as it has been seen to maintain viral suppression in virally suppressed patients who cannot be on regimens containing TDF, TAF, or ABC. A regimen of DRV/r + 3TC is thought to be promising, given the positive results of recently completed study[1]. In cases of virologic failure, the DHHS does not currently recommend a regimen of a single NRTI with a boosted PI.

IAS: The IAS does not specifically recommend any regimens for treatment-experienced patients in cases of both virologic failure or suppression. However, they recommend to consider switching patients on older regimens to a variety of simplified regimens (i.e. from use of old NRTIs as they have long-term toxic effects, or older PIs that have higher pill burdens and are more metabolically toxic than DRV or ATV).

Other Considerations


  • Must be taken with food
  • Low risk of resistance with virologic failure, even with intermittent adherence
  • PI booster (ritonavir) interacts with many other drugs
  • Possible side effects include rash, severe rash with fever, and elevated transaminases
  • Caution advised when administering to patients with severe sulfonamide allergy


Efficacy in Clinical Trials






ATV/r+3TC vs ATV/r+2NRTI

266 tx-experienced

90% of patients who switched to ATV/r + 3TC maintained virologic suppression vs. 80% of patients who remained on ATV/r +2NRTI[3].


ATV/r+3TC vs ATV/r+2NRTI

286 tx-experienced

The dual-treatment regimen was found to be noninferior to the triple-treatment regimen. At week 48, 112 (84%) of the dual-treatment group had virological response versus 105 (78%) in the triple-treatment group. Treatment discontinuations were also less frequent in the dual-treatment group as compared to the triple-treatment group [4].


LPV/r+3TC vs 2NRTI+LPV/r

426 tx-naive

At week 48, 189 patients (88.3%) in the dual-therapy group and 169 (83.7%) in the triple-therapy group had viral suppression[5]


LPV/r+3TC vs LPV/r+2NRTI

250 tx-experienced

The dual-treatment group was found to be noninferior to the triple-treatment group as 110 (86.6%) of triple-treatment patients responded to treatment versus 108 (87.8%) of dual-treatment patients [2].



94 tx-experienced

In a retrospective analysis of patients with at least six months of virological suppression switched to 3TC plus DRV/r demonstrated continued virological suppression with a favorable safety profile[1]

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  1. Citekey 142 not found
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  5. Citekey /180 not found