FDA warning of drug interactions between boceprevir and some HIV protease inhibitors
The US FDA have notified health care professional and patients that drug interactions between boceprevir and certain ritonavir- boosted HIV protease inhibitors (atazanavir, lopinavir and darunavir) can significantly reduce the effectiveness of these drugs when used together. 
Merck, the manufacturer’s of boceprevir also issued a drug warning giving the pharmacokinetic data and the recommendation that “coadministering boceprevir and ritonavir-boosted PIs is not recommended”. 
Source: FDA list serve
- FDA warning. Victrelis (boceprevir) and ritonavir-boosted Human Immunodeficiency Virus (HIV) protease inhibitor drugs: drug safety communication – drug interactions, (9 February 2012).
- Merck. Dear Healthcare Professional letter. Results of pharmacokinetic study in healthy volunteers given VICTRELIS (boceprevir) and ritonavir-boosted HIV protease inhibitors may indicate clinically significant drug interactions for patients coinfected with chronic hepatitis C and HIV. (6 February 2012).