Medications used to boost the levels of other HIV antiretrovirals are the most likely out of all ARVs to have dangerous interactions with common illicit drugs, as well as with erectile dysfunction drugs and tranquilizers, aidsmap reports. Publishing their findings in the journal AIDS, researchers conducted a review of available literature and considered pooled expert opinion about the interaction between ARVs and recreational drugs common among British HIV-positive gay men.

The two booster ARVs, Norvir (ritonavir) and Tybost (cobicistat), are both processed by liver enzymes that also metabolize numerous recreational drugs considered in the study. The result of this mutual use of a metabolic pathway may be that the recreational drugs are metabolized more slowly and may reach dangerous levels in the body.

Norvir and Tybost are included in the combination tablets Kaletra (lopinavir/ritonavir), Stribild (elvitegravir/cobicistat/tenofovir/emtricitabine), Evotaz (atazanavir/cobicistat) and Prezcobix (darunavir/cobicistat).

The researchers found that these two boosters are most likely to interact dangerously with crystal meth, MDMA (ecstasy) and mephedrone (bath salts). There is a moderate level of potential danger of Norvir and Tybost interacting with ketamine (K), erectile dysfunction drugs such as Viagra, and benzodiazepines (tranquilizers such as Xanax).

The study authors recommend that physicians treating HIV-positive individuals who are using such drugs consider switching them to a different ARV regimen that does not include a booster.

A separate recent study recently found that people with HIV who use recreational drugs commonly skip doses of ARVs in anticipation of such consumption.

To read the aidsmap article, click here.

To read the study abstract, click here.