Rivaroxaban prescribing in a Saudi tertiary care teaching hospital

Clinical Associations with the differences in rivaroxaban dosing in patients with atrial fibrillation stratified by three renal function formulae

Background

Clinical trials used Cockcroft-Gault (CG) formula to calculate the estimated glomerular filtration rate (eGFR) in order to dose rivaroxaban for patients with atrial fibrillation (AF).

Objectives

The aim of this study is to evaluate rivaroxaban dosing appropriateness in patients with AF with or without renal impairment based on the CG formula and other formulae, including Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and the isotope dilution mass spectrometry (IDMS) traceable Modification of Diet in Renal Disease (MDRD) Study equation and the associated clinical outcomes.

Methodology

A retrospective cohort study conducted at Sultan Qaboos University Hospital (SQUH) from 1st January 2016 to 31st December 2020, included all adult patients (≥ 18 years) treated with rivaroxaban for AF and followed up for one year after starting the treatment.

Results

Based on the CG formula, the rivaroxaban dose was inappropriately prescribed in 27% of the patients (21% overdosed and 6% underdosed). Higher baseline creatinine (P=0.0014) and concurrent use of antiplatelet therapy (P<0.001) were associated with the tendency to rivaroxaban overdosing. Higher Body Mass Index (BMI) (P=0.002), female sex (P=0.032), and CKD (P=0.003) were associated with rivaroxaban underdosing. The degree of agreement between the renal function tests when comparing MDRD vs CG and CKD-EPI vs CG in terms of estimated glomerular filtration rate/creatine clearance (eGFR/CrCl) calculation was moderate (κ=0.46) and poor (κ=0.00), respectively, while, in terms of rivaroxaban dose appropriateness was almost perfect (κ=0.82) and substantial (κ=0.77). Clinical outcomes measured by stroke and bleeding events were not significantly different according to the appropriateness of the rivaroxaban dose.

Conclusion

This study has shown a relatively high consistency with the gold standard in dosing rivaroxaban in AF patients using CG formula. Treatment efficiency and safety were not affected by the proportion of dose inappropriateness found in this cohort.

Comparative Effectiveness and Safety of Rivaroxaban and Warfarin for Stroke Prevention in Patients with Non-Valvular Atrial Fibrillation in an Omani Tertiary Care Hospital

Objective:

The aim of the study was to compare the effectiveness and safety of rivaroxaban and warfarin as well as to determine the appropriateness of dosing and prescribing of rivaroxaban in Omani patients with non-valvular atrial fibrillation (NVAF).

Methods:

This retrospective cohort study was conducted using the Royal Hospital data registry. The study included all adults newly diagnosed with NVAF and treated with rivaroxaban or warfarin. The outcomes measured include ischaemic stroke, gastrointestinal bleeding (GIB), non-gastrointestinal bleeding (NGIB), as well as appropriateness of dosing and prescribing of rivaroxaban.

Results:

The analysis included 96 rivaroxaban users and 183 warfarin users; 51% of the cohort included males. There were no significant differences observed in the risk of ischaemic stroke between the two groups (hazard ratio (HR), 1.1; 95% confidence interval (CI): 0.4-3.4; p=0.8). However, those on rivaroxaban exhibited a significantly higher rate of GIB compared to those on warfarin (HR, 5.9; 95% CI: 2.9-11.7; p=0.001). There were no differences observed with regards to NGIB between the two groups (HR, 0.9; 95% CI: 0.4-1.9; p=0.8). Dosing and prescribing of rivaroxaban were found to be appropriate in 89% of the patients, with only 6% being prescribed an inappropriately lower dose.

Conclusion:

The study demonstrated no significant differences in the risk of ischaemic stroke or NGIB between rivaroxaban and warfarin groups in newly diagnosed NVAF patients. However, rivaroxaban users were found to have a significantly higher risk of GIB. Rivaroxaban was appropriately prescribed to the majority of the patients, and only a small proportion of the group received an inappropriately lower dose of rivaroxaban.

Appropriateness of Prescribing Rivaroxaban at King Khalid University Hospital Riyadh

Background and aim

Warfarin is recognized as a first-line treatment for different coagulopathy conditions; however, guidelines also encourage the use of rivaroxaban as an alternative option. The recent approval of the novel oral anticoagulants (NOACs) has led to swift changes in anticoagulant prescribing practices. This study aimed to review rivaroxaban prescribing patterns in adult patients in a large tertiary care setting in the Kingdom of Saudi Arabia (KSA).

Materials and methods

A retrospective cross-sectional study was conducted from January 2019 to September 2020 at King Khalid University Hospital, Riyadh, KSA. Data was collected from the patient's medical record. Data analysis was performed with the Statistical Package for the Social Sciences (SPSS) IBM Corp. Released 2013. IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY: IBM Corp.

Results

A total of 309 patients were included in this study. Rivaroxaban use for non-valvular atrial fibrillation (NVAF) was relatively higher than deep venous thrombosis/pulmonary embolism (DVT/PE). 45% of the patients had NVAF, followed by DVT/PE (26%), and DVT/PE prophylaxis (25%). Fifty-six patients, (18%) received an inappropriate dose of rivaroxaban for NVAF.

Conclusion

This study found a relatively high percentage of inappropriate rivaroxaban prescribing, predominantly because of inappropriate dosing, which can potentially increase medication-related events. The use of rivaroxaban should be monitored to increase the appropriateness of therapy and improve patient safety.

Medication errors associated with direct-acting oral anticoagulants: analysis of data from national pharmacovigilance and local incidents reporting databases

Background

For more than a decade, direct oral anticoagulants (DOACs) have been approved in clinical practice for multiple indications such as stroke prevention in non-valvular atrial fibrillation treatment of deep vein thrombosis and pulmonary embolism. This study aimed to explore the nature and contributory factors related to medication errors associated with DOACs in hospital settings.

Methods

Analysis of error reports using data from (a) Saudi Food and Drug Authority pharmacovigilance database and (b) local incidents reporting system from two tertiary care hospitals were included. Errors reported between January 2010 to December 2020 were also included. Statistical analyses were performed using IBM (SPSS) Statistics Version 24.0 software.

Results

A total of 199 medication error incidents were included. The mean (range) age of affected patients was 63.5 (19–96) years. The mean reported duration of treatment when incidents happened was 90 days, with a very wide range from one day to 12 months. Prescribing error was the most common error type representing 81.4% of all errors. Apixaban was the most frequent drug associated with error reporting with 134 (67.3%) incidents, followed by rivaroxaban (18.6%) and dabigatran (14.1%). The majority of the patients (n = 188, 94.5%) showed comorbidities in addition to the conditions related to DOACs. Polypharmacy, an indication of treatment and duration of therapy were amongst the important contributory factors associated with errors.

Conclusions

This observational study demonstrates the nature of DOAC related medication errors in clinical practice. Developing risk prevention and reduction strategies using the expertise of clinical pharmacists are imperative in promoting patient safety associated with DOAC use.

Patient-guided modifications of oral anticoagulant drug intake during Ramadan fasting: a multicenter cross-sectional study

Fasting Ramadan is known to influence patients’ medication adherence. Data on patients’ behavior to oral anticoagulant (OAC) drug intake during Ramadan is missing. We aimed to determine patient-guided modifications of OAC medication regimen during Ramadan and to evaluate its consequences. A multicenter cross-sectional study conducted in Saudi Arabia. Data were collected shortly after Ramadan 2019. Participants were patients who fasted Ramadan and who were on long-term anticoagulation. Patient-guided medication changes during Ramadan in comparison to the regular intake schedule before Ramadan were recorded. Modification behavior was compared between twice daily (BID) and once daily (QD) treatment regimens. Rates of hospital admission during Ramadan were determined. We included 808 patients. During Ramadan, 53.1% modified their intake schedule (31.1% adjusted intake time, 13.2% skipped intakes, 2.2% took double dosing). A higher frequency of patient-guided modification was observed in patients on BID regimen compared to QD regimen. During Ramadan, 11.3% of patients were admitted to hospital. Patient-guided modification was a strong predictor for hospital admission. Patient-guided modification of OAC intake during Ramadan is common, particularly in patients on BID regimen. It increases the risk of hospital admission during Ramadan. Planning of OAC intake during Ramadan and patient education on the risk of low adherence are advisable.