The United States Department of Health and Human Services (HHS) has released an updated version of its “Guidelines for the Use of Antiretroviral Agents in HIV Infected Adults and Adolescents.”

The guidelines include updated information on initial combination regimens for previously untreated (treatment-naïve) people with HIV.

According to the guidelines, antiretroviral regimens may be classified as preferred regimens, alternative regimens, or acceptable regimens. Preferred regimens are recommended as the best treatment regimens for most people starting antiretroviral therapy.

Alternative regimens, while effective, have potential disadvantages when compared with preferred regimens. Acceptable regimens decrease the amount of HIV virus activity but lack data from large clinical trials on efficacy or might have greater side effects or potential for drug interactions.

The guidelines are intended for use by HIV care practitioners when treating HIV-positive adults and adolescents in the U.S. They were last updated in January.

Updates on antiretroviral initiation in HIV-positive people are summarized below.

Non-Nucleoside Reverse Transcriptase Inhibitor (NNRTI)-Based Regimens

The updated guidelines list Edurant (rilpivirine) as an alternative NNRTI option for initial therapy in treatment-naïve patients (see related AIDS Beacon news). Edurant was approved by the U.S. Food and Drug Administration in May.

Information on Edurant has also been added to the guide’s tables on drug interactions, drug characteristics, and dosing recommendations for people with kidney or liver problems.

In addition, all Viramune (nevirapine)-based regimens have been reclassified in the updated guidelines as acceptable treatment options for patients beginning antiretroviral therapy. Previously, Viramune plus zidovudine/lamivudine (Combivir) was classified as an alternative regimen, while Viramune plus Epzicom (abacavir/lamivudine) and Viramune plus Truvada (emtricitabine/tenofovir) were classified as regimens that were acceptable but required caution when used.

Protease Inhibitor-Based Regimens

The updated guidelines now list Norvir (ritonavir)-boosted Prezista (darunavir) plus Epzicom as an alternative regimen. This regimen was previously listed as an acceptable regimen that required more data.

Regimens with unboosted Lexiva (fosamprenavir) are no longer listed as protease inhibitor options for treatment-naïve patients because these regimens are less effective than other protease inhibitor-based regimens. In addition, patients who experience virologic failure (failure of antiretrovirals to control HIV replication) while taking Lexiva may develop resistance to Prezista.

Isentress-Based Regimens

The new guidelines reclassify Isentress (raltegravir) plus Epzicom as an alternative regimen. The regimen was previously classified as acceptable but in need of additional data.

Dual-Nucleoside Reverse Transcriptase Inhibitor (NRTI) Options

The updated guidelines list zidovudine/lamivudine as an acceptable dual-NRTI option. This option was previously listed as an alternative option, but was reclassified because the combination is associated with greater side effects compared with Truvada and Epzicom and requires twice daily dosing. Zidovudine/lamivudine, however, is still the preferred dual-NRTI for pregnant women receiving antiretroviral therapy to avoid mother-to-child HIV transmission.

Didanosine (Videx) plus Epivir (lamivudine) is no longer listed as a dual-NRTI option for initial treatment because the combination has the least data from clinical trials and has more side effects compared with other dual-NRTI options.

In the updated guidelines, the authors point out that Ziagen (abacavir), which is also a component of Epzicom and Trizivir (zidovudine/lamivudine/abacavir), may increase the risk of heart attack; however, they note that this association is not definitive.

For more information, please see The Guidelines for the Use of Antiretroviral Agents in HIV-Infected Adults and Adolescents (pdf).