Stable Virologic Suppression during Raltegravir plus Atazanavir Dual-Therapy Taken Every other Day: A Case Report

Adherence to Highly Active Antiretroviral Therapy can be affected by a number of factors limiting the outcome of the treatment. We report the case of a 39 year-old HIV-HCV co-infected woman in stable virologic suppression and immune recovery during a raltegravir plus unboosted atazanavir dual-therapy taken every other day. Measurement of HIV-1 RNA plasma levels (viral load), CD4+ T-cell counts and the therapeutic drug monitoring through validated high-performance liquid chromatography methods, were performed to assess the effectiveness of this regimen. Our data on raltegravir pharmacokinetics in association with atazanavir show adequate minimum effective concentrations of raltegravir throughout 36 and 48 hours despite the every other day intake of the drug. Further studies are recommended in order to identify the determinants that could enable a reduction in antiretroviral dosing frequency in case of difficult management of HIV-infected patients due to low adherence to therapy. By reporting our medical experience, we focused on the utility of performing therapeutic drug monitoring especially in cases of poor adherence, drug and/or alcohol abuse, co morbidities and co-administration of other drugs.