AFib patients most likely to discontinue dabigatran during first 6 months of treatment

Nearly three-quarters of atrial fibrillation patients taking dabigatran remain adherent to the medication two years after filling their first prescription, while just over 25% discontinue the drug for various reasons, according to an analysis published in the American Journal of Cardiology.

The analysis, spearheaded by principal supervisor Robby Nieuwlaat, PhD, of McMaster University in Ontario, Canada, found that patients on dabigatran were most likely to stop using the anticoagulant during their first six months of treatment. Oral anticoagulants (OACs) have long been recommended for stroke prevention in individuals with AFib, but Nieuwlaat and colleagues said medication adherence is still a major problem for patients, with one-year discontinuation rates exceeding 50% at certain points in time.

“While some evidence indicates discontinuation rates may be lower with non-vitamin K antagonists (NOACs) versus vitamin K antagonists, periods of risk and reasons for NOAC discontinuation remain poorly understood,” the authors wrote. “Reasons for early discontinuation may differ from reasons patients discontinue after more enduring periods of stable treatment, and this information may be informative for clinicians implementing management strategies to address the important clinical barrier of treatment persistence.”

Nieuwlaat and his team enrolled 4,859 patients in their study, all of whom were prescribed dabigatran in diverse practice settings and followed for two years. Patients were on average 70 years old and just over half were male.

The researchers reported that persistence probability in the first six-month period of treatment was the lowest in the study: 83.7%. Adherence increased with each six-month period thereafter:

  • 6-12 months: 92.5% 
  • 12-18 months: 95.1% 
  • 18-24 months: 96.3%

A total of 1,305 patients—26.9% of the study pool—discontinued dabigatran during the trial, the authors said. Of those people, 35% reported adverse events as the reason they stopped using the drug.

Patients persistent with treatment at one year were at least 90% likely to remain persistent at two years, suggesting some individuals might benefit from earlier interventions designed to improve medication adherence. Stroke incidence rates were 1.76 in patients who discontinued dabigatran without switching to another NOAC and 1.02 in those who switched.

“Patients with certain characteristics may simply be more prone to discontinue earlier, due to factors such as lifestyle, low treatment satisfaction or poor tolerance among others,” Nieuwlaat et al. wrote. “Closer clinical management in the early period could be warranted to improve commitment to treatment or to help manage side effects and identification of characteristics associated with discontinuation could support targeted interventions in these patients.”