Predictive factors for obtaining a correct therapeutic range using antivitamin K anticoagulants: a tertiary center experience of patient adherence to anticoagulant therapy

The Role of the Pharmacist in a Patient's Care for Individuals Undergoing Anticoagulant Therapy: A Case Report

Achieving clinical effectiveness with vitamin K antagonists (VKAs) requires a Time in Therapeutic Range (TTR) above 65%. TTR is influenced by genetics (CYP2C9, VKORC1, CYP4F2), treatment adherence, and knowledge. The SAMe-TT2R2 algorithm is used to assess VKA treatment suitability. In this case report, SAMe-TT2R2 and pharmacogenetic analysis were used to improve oral anticoagulant management in a patient with poor control of INR. An 84-year-old, obese male with atrial fibrillation, undergoing acenocoumarol therapy, had a suboptimal TTR. An assessment with the SAMe-TT2R2 algorithm indicated a favorable profile for VKA use. An educational intervention on vitamin K-rich foods was conducted, and his physician was informed about the interaction between omeprazole and acenocoumarol, recommending its replacement with pantoprazole. This intervention was accepted by the physician and, three months post-intervention, the patient's TTR improved to 100%. Poor adherence and limited knowledge contributed to treatment failures in patients with a good VKA profile. Pharmaceutical interventions significantly improved TTR management. Patients with favorable genetic and clinical profiles could achieve adequate control of their anticoagulant medication through these interventions. Predictive tools may help select patients who can effectively and safely use VKAs through pharmaceutical interventions.

Therapeutic compliance with rivaroxaban in preventing stroke in patients with non-valvular atrial fibrillation: CUMRIVAFA study

OBJECTIVE

To assess compliance with treatment with rivaroxaban in patients with non-valvular atrial fibrillation.

METHODS

Prospective, longitudinal, multicenter study, developed in 160 Spanish primary or specialized care centers. We included 412 patients treated with rivaroxaban, prescribed for stroke prevention. Three visits were conducted: baseline, 6 and 12 months. Compliance was measured by using electronic monitors (MEMSs) that use a digital record in the form of a microchip in the lid of the drug container that automatically controls its opening and registers the time and date of the opening. We calculated the average compliance percentage (CP), global and daily compliance. We considered compliance to be when CP was 80-100%.

RESULTS

Three hundred and seventy patients ended the study (mean age 75.19, SD: 7.5 years). Global compliance was 84.1% (CI = 79.21-88.99%) and 80.3% (CI = 74.98-85.62%) after 6 and 12 months respectively. Daily compliance was 83.5% (CI = 78.53-88.57%) and 80% (CI = 74.65-85.35%) at 6 and 12 months. Significant differences in the CP between 6 and 12 months were observed. Global CP was 90.77% after 6 months and 89.65% at the end of the study. Daily CP was 90.14% and 87.66% at 6 and 12 months. There were significant CP differences between 6 and 12 months. Non-compliance was associated with a higher number of concomitant diseases, number of drugs taken and weight.

CONCLUSIONS

The percentage of compliance with rivaroxaban was high. A profile of variables that need to be modified in current medical practice, associated with non-compliance, was detected.