A majority of people taking antiretrovirals (ARVs) to treat HIV could switch to newer regimens with improved side effect profiles, according to an analysis of Australians living with the virus, aidsmap reports. Publishing their findings in PLOS ONE, researchers analyzed the treatment history and drug resistance information of 120 people taking two or more of four commonly used, relatively older ARVs that come with notable safety and tolerability concerns.

The researchers dubbed the four ARVs in question the “RATE” drugs after their generic names: Norvir (ritonavir), which has drug interaction problems; Ziagen (abacavir), which can cause an allergic reaction, is less potent when viral loads are higher and may elevate the risk of cardiovascular disease; Viread (tenofovir), which may reduce bone density and cause kidney dysfunction; and Sustiva (efavirenz), which is linked to neuropsychiatric disturbances and raised lipid levels.

By comparison, the following drugs have been approved more recently and boast improved tolerability: Edurant (rilpivirine), Intelence (etravirine), Reyataz (atazanavir), Isentress (raltegravir) and Selzentry (maraviroc). And then there is the older Epivir (lamivudine), which also has a better side effect profile.

Genetic testing of the virus, necessary to determine if Selzentry would be a viable option, was not available for 54 percent of the participants and was not successful for 8 percent of them.

If all the participants were indeed susceptible to Selzentry, then the researchers estimated that 98 percent of them could feasibly switch to at least one ARV regimen with two safer active drugs. Eighty-nine percent could switch to a regimen with three of the safer options. These percentages dropped to a respective 94 percent and 87 percent when factoring in the unknown Selzentry susceptibility.

After conducting an analysis of the Australian HIV Observational Database (AHOD), the investigators found that 57 percent of Australians were on ARV regimens including two or more RATE drugs and could potentially switch to newer therapies.

To read the aidsmap story, click here.

To read the study, click here.