The evening dose of AbbVie’s hepatitis C virus (HCV) treatment Viekira Pak (ombitasvir/paritaprevir/ritonavir; dasabuvir) may interact harmfully with HIV protease inhibitors (PIs), Medscape reports. Publishing their findings in Clinical Infectious Diseases, researchers conducted five Phase I, multiple-dose, open-label pharmacokinetic studies among 144 HIV-negative volunteers.

The participants were evenly assigned to groups in which the researchers studied the effects of Viekira Pak on HIV PIs or vice-versa. PIs studied included Norvir (ritonavir)–boosted Reyataz (atazanavir), Prezista (darunavir) and Kaletra (Norvir–boosted lopinavir).

The dasabuvir component of Viekira Pak is taken twice daily, while the remainder of the treatment is taken only once daily.

The combination of Viekira Pak with the HIV drugs was generally well tolerated. 

The morning doses of Reyataz and Prezista showed no clinically meaningful interaction with Viekira Pak. However, the evening dose of Prezista or Norvir–boosted Reyataz led to higher exposures of the paritaprevir and ritonavir components of Viekira Pak. The researchers do not recommend combining those HIV drugs with Viekira Pak as part of an evening regimen.

To read the study abstract, click here.

To read the Medscape article, click here (free registration with the site is required).