HIV/HCV Coinfection, Regimen Complexity, and Response to Treatment

Investigators in Spain have identified a relationship between higher-complexity medication regimens and a lower likelihood of sustained viral response (SVR) after treatment for hepatitis C virus (HCV) infection.

For reasons that are not fully understood, new treatments against hepatitis C virus (HCV) infection are less effective in patients with HCV/HIV coinfection than in patients with HCV infection alone. The growing complexity of medication regimens for patients with HIV/HCV coinfection makes these patients good candidates for medication counseling programs. Identifying the correct patients that might benefit most from counseling services may help patients attain a better response to treatment.

In a recent paper, researchers in Spain investigated some of the factors associated with lower rates of sustained viral response (SVR). The investigators intended to find a relationship between the complexity of each patient's regimen with the likelihood of SVR. Investigators found that the likelihood of response was lower in patients with more complex regimens.

The complexity of treatment was measured using an index that takes into account convenience factors such as the complexity of special instructions, and the number of doses taken daily. The lowest index of medication complexity was 7.25, and the highest score was 13.5.

In the retrospective analysis, most patients (75%) were men and just under half (45%) of the 156 patients had HIV/HCV coinfection. Patients with HIV/HCV coinfection were 64% less likely to experience SVR than patients with HCV infection alone. Greater medication regimen complexity further reduced the likelihood of SVR. Patients with high-complexity medication regimens were 33% less likely to experience a cure than patients treated with less complex regimens.

Complicated medication regimens were more common among patients with HIV/HCV coinfection than in patients with HCV infection alone. More than half (60%) of patients with HCV infection who were not infected with HIV used low-complexity regimens (complexity score: 7.25 to 7.75). Fewer than 15% of patients with HIV/HCV coinfection had a medication regimen complexity score in this low range, and almost 70% of patients with HIV/HCV coinfection used high-complexity regimens (complexity score: 9.5 to 12).

Connecting greater complexity with reduced clinical response, the investigators found that HIV/HCV coinfection is not only an independent risk factor in reducing the likelihood of treatment response, but regimen complexity may further reduce the likelihood of attaining SVR among coinfected patients. Selecting patients who have more complicated regimens using a scoring tool (available at www.farmaciavalmecpv.com/consulta/actividad/indice-de-complejidad) may help identify patients in need of assistance to attain better medication regimen adherence. Although the scoring tool is only available in Spanish at this time, the names of the medications on the list are recognizable, and the scoring tool is based on an index devised by Martin et al in 2007.