Physician Awareness of Drug-Drug Interactions in HIV/HCV Coinfection

Potentially harmful drug-drug interactions (DDIs) can occur between combination antiretroviral therapy (cART) and non-cART comedication in patients with HIV being concurrently treated for hepatitis C virus (HCV) with direct-acting antivirals (DAAs). An analysis of physician prescription patterns published in HIV Medicine suggested physicians were aware of potential DDIs between comedication and DAAs, but greater awareness is still required concerning category 3 interactions.

Evidence has previously existed for DDIs occurring in patients with HIV being simultaneously treated for HCV; however, questions remained about how physicians handle these risks and the consequences for HCV and HIV treatment outcomes.

Data from 423 coinfected Dutch patients with HIV/HCV were obtained from the ATHENA database. Median age at time of DAA initiation was 50 years, and the majority of patients (68%) were infected with HCV genotype 1. Of the patients, 99% received treatment with cART, and 59% also used non-cART medication. Treatment with non-cART medication that could cause potential category 2/3 DDIs was discontinued in 20% of patients before starting DAA treatment. Overall, 47% of patients had a category 2/3 DDI between their DAA regimen and cART. “Category 2/3 DDIs were prevented by switching cART in 78 of 147 (53%) and 47 of 49 (98%) patients,” respectively, and sustained virologic response was achieved in 87% of patients after 12 weeks of treatment.

The data indicated that Dutch physicians were aware of DDI risks and adjusted prescriptions accordingly, although non-cART drugs were less often discontinued. Specifically, researchers found 6 cases involving the use of drugs with category 3 DDIs, and in 4 of these cases, the drugs were not discontinued.

Although overall awareness of conflicts was adequate and sustained virologic response was achieved in the majority of patients, the investigators stated there is still “room for improvement in relation to modifying potentially interacting non-cART co-medication.”

Reference

Smolders EJ, Smit C, de Kanter C, et al; ATHENA National HIV Observational Cohort. Management of drug interactions with direct-acting antivirals in Dutch HIV/hepatitis C virus-coinfected patients: adequate but not perfect [published online December 1, 2017]. HIV Med. doi: 10.1111/hiv.12570