Why are antiretroviral regimens changed in treatment-experienced patients with HIV infection?

Updated: Apr 18, 2019
  • Author: R Chris Rathbun, PharmD, BCPS (AQ-ID), AAHIVP; Chief Editor: John Bartlett, MD  more...
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With increased knowledge of resistance development and improvements in tolerability and potency of antiretroviral agents, altering therapy in patients with virologic suppression has become a more common practice. Some primary reasons for regimen change include [8] :

  • simplification to decrease pill burden or frequency of administration
  • tolerability/adverse effect profile
  • avoidance of drug-drug interaction
  • elimination of dosing requirements (food/fluid, timing)
  • pregnancy or future pregnancy planning
  • regimen cost

The over-arching goal when switching therapy is to maintain virologic suppression without endangering future options through resistance development. When considering therapy changes, a thorough patient history should be completed reviewing the patient’s previous antiretroviral exposure including response to therapy, tolerance, and previous resistance development. As previous resistance mutations may not show up on current testing, it is important to note all previous resistance testing and results. [8]

In general, switches can be made within antiretroviral classes or among classes. For most patients, maintaining a 3-drug regimen is advised; though in some select cases, patients may be maintained on a 2-drug regimen. [8] Currently, only dolutegravir plus rilpivirine or a boosted-PI plus emtricitabine or lamivudine combination are recommended for dual therapy regimens. Monotherapy regimens are not recommended for any patient at this time. Monitoring should be increased following an ART switch to assure tolerance and maintenance of viral suppression. The guidelines recommend patient contact within 1-2 weeks of switch to evaluate regimen adherence and tolerance, and laboratory monitoring 4-8 weeks following the switch for viral suppression and other lab concerns. [8]

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