There is a national prescribing trend for rivaroxaban (Xarelto; Bayer), one of four drugs known as direct oral anticoagulants (DOACs), and prescription is steadily rising. The drug has six licensed indications, with four different dosages and at least five possible durations of therapy, depending on the condition being treated. Anecdotal evidence suggests that some patients have inadvertently remained on rivaroxaban in the long term in cases where the drug had been indicated for only a short-term treatment; for example, for prophylaxis of venous thromboembolism (VTE) following hip replacement surgery in the older patient in a care-home setting.
In response to these safety concerns, NHS Southampton City CCG conducted an audit to ensure rivaroxaban was being prescribed for the correct duration for short-term licensed indications: prophylaxis of VTE following knee or hip surgery; treatment of deep vein thrombosis (DVT) or pulmonary embolism (PE); prophylaxis of recurrent DVT or PE; and prophylaxis of atherothrombotic events in acute coronary syndrome.
The medicines management team at NHS Southampton City CCG developed an audit tool, and data collection was undertaken by all 30 general practices in Southampton as part of the prescribing incentive payment scheme.
GP clinical system searches were run to exclude patients on rivaroxaban with an atrial fibrillation diagnosis because this condition warrants long-term (lifelong) therapy. The exclusion of these patients enabled a smaller target patient group with variable short-term durations to be audited. Data were examined by the medicines management team, and ‘key actions’ were highlighted to GPs, including incorrect dosing, lack of indication documented, or duration of intended treatment being exceeded. The audit was repeated four months later to ensure that recommendations had been implemented and that further actions had been highlighted.
In the initial audit, 27% (328) of all patients prescribed rivaroxaban received the DOAC for indications unrelated to atrial fibrillation. Of that group, 8% (26) were inappropriately overprescribed rivaroxaban according to the intended duration. Three other patients were found to have been overprescribed rivaroxaban in the repeat audit at four months. These patients were flagged to their GPs, and anticoagulant therapy was stopped. Therefore, in total, 29 patients had their overprescribing of rivaroxaban stopped as a result of the audit cycle. This resulted in an annual potential saving of £655 per patient stopped. As a direct result of this audit cycle, an annual £19,000 cost saving was made. In addition, 33 patients had ‘end dates’ added to their rivaroxaban prescriptions to avoid their short-term anticoagulation treatments overextending. The value of additional saving made through the additional intervention is unknown.
The complexity of rivaroxaban’s various doses, indications and durations of therapy has resulted in patients being inadvertently left on the treatment for the long term, when the intended duration of treatment has been omitted or has not been clearly documented in the notes. This is exacerbated by the fact that rivaroxaban is also prescribed for the prevention of ischaemic stroke in patients with atrial fibrillation — this is a lifelong treatment.
We have shown the importance of documenting therapy duration through this work, and the need for an ongoing educational message to all prescribers of anticoagulants.
Patients previously anticoagulated with warfarin have regular planned contact with healthcare professionals for their INR blood tests, but patients on rivaroxaban have no such regular follow-up. Our audit shows that review and the stopping of short-term rivaroxaban medication sometimes does not happen. Particular care should be applied when adding rivaroxaban to a patient’s ‘repeat’ list of medications. This was particularly relevant to 32% of the audit cohort, who resided in care homes, where the idea for this work originated. It is therefore essential for general practices to have robust systems in place to ensure that the intended treatment duration for all patients prescribed DOAC medication is clearly documented and readily accessible during the generation of prescriptions.
Care homes pharmacist and medicines management team member,
NHS Southampton City CCG