Medication Adherence Declines Steadily in Hepatitis C Patients

Patients being treated for chronic hepatitis C become less likely to take their medications over time, according to a study published in the Annals of Internal Medicine in September. In light of these findings, which also demonstrated better response to the drugs when they’re taken correctly, the researchers noted that clinicians should assess patients for barriers to medication adherence throughout their treatment, and develop strategies to help them stay on track.

“Our findings are particularly timely since many chronic hepatitis C patients are now being prescribed direct-acting antiviral drugs, which have a complex dosing regimen that may be even harder for patients to maintain than the two-drug standard therapy,” said Vincent Lo Re, MD, MSCE, of Perelman School of Medicine at the University of Pennsylvania, the study’s lead author, in a statement. “These data show us that we need to develop and test interventions to help patients be more successful at taking their medicine and have the best chance at being cured.”

In the study, the authors identified literacy issues, financial hurdles, and socioeconomic problems such as unstable living situations as factors that can affect patients’ abilities to properly maintain their drug regimen. Providers, they said, can help improve medication adherence by taking steps such as refilling patients’ pill boxes for them, creating easy-to-follow dosing and refill schedules, and helping them set alarms to remind them to take their medicine.

Dr. Lo Re and colleagues studied 570 chronic hepatitis C patients who had been prescribed the standard treatment for the virus—pegylated interferon (given as a single weekly shot) and ribavirin (a twice-daily oral medicine)—using pharmacy refill data and test results for virologic response during treatment. They found that patients who refilled their prescriptions on time had a higher likelihood of being cured of the infection. However, over the course of patients’ treatment, adherence waned—more often for ribavarin. This pattern, according to the authors, is similar to that among patients taking drugs for other chronic conditions, during which patients can develop “pill fatigue.”

The newer, more powerful direct-acting antiviral drugs, which must be taken every 8 hours, will add to the complexity, and cost, of chronic hepatitis C treatment. In addition, if the newer direct-acting antiviral drugs aren’t taken properly, the hepatitis C virus may become resistant to treatment, compromising the chance of cure, they noted.

Monitoring for and treating drug-related side effects may also be a key factor in boosting adherence, Dr. Lo Re noted. The study results showed that patients who received medication for thyroid dysfunction, anemia, or low white blood cell counts were more likely to remain adherent to their antiviral therapy. Although those drugs added more steps into their self care, the authors noted that the resulting relief for symptoms, including depression, fatigue and irritability, and more frequent visits to health care providers, typically required with administration of these drugs, may play a role in patients’ ability to maintain the regimen overall.

"We know that a major barrier to adherence is side effects of these drugs. People don’t feel good when they’re on them," Dr. Lo Re said. "If we can identify those problems and treat them when they occur, patients may be more motivated and feel well enough to continue with their prescribed regimen."