Rivaroxaban for the treatment of Deep Vein Thrombosis in patients unsuitable for vitamin K antagonists

Transcription

1 Rivaroxaban for the treatment of Deep Vein Thrombosis in patients unsuitable for vitamin K antagonists Traffic light classification- Amber 2 specialist initiation Information sheet for Primary Care Prescribers Relevant Licensed Indications Treatment of deep vein thrombosis (DVT), and prevention of recurrent DVT and pulmonary embolism (PE) following an acute DVT in adults. 1 Therapeutic Summary Most patients with venous thromboembolic disease are anticoagulated with a Low Molecular Weight Heparin (LMWH) whilst the diagnosis is established and then proceed to anticoagulation with warfarin (a vitamin K antagonist). A number of patients are however, unsuitable for warfarin due to anticipated poor control or bleeding risk and will either continue on a LMWH long term, or be treated with rivaroxaban. Potential indications for continued treatment with rivaroxaban are: allergy to warfarin extremely unstable warfarin control, compliance problems with warfarin intravenous drug users (e.g. may have poor veins for INR sampling or there may be concerns over adherence with INR monitoring) liver disease anticoagulation in malignancy - active newly diagnosed patients with malignancy should not be warfarinised until their treatment plan is agreed and warfarin control is often very unstable in these patients. Patients with chronic malignant conditions eg. prostate cancer may be suitable for warfarin, but treatment should be reviewed by the specialist team if liver metastases are present. In this patient group LMWH s are first line, rivaroxaban should only be used if LMWH s are contraindicated Medicines Initiation Rivaroxaban will be initiated in secondary care and the hospital will provide the first 21 days treatment on discharge. The GP will be asked to provide any further supplies (please note dose change after day 21 as below). Dosage and route of administration The usual treatment dose is 15mg twice daily to be used from day 1 to 21, then 20mg daily thereafter. 1 In patients with moderate renal impairment (creatinine clearance ml/min) the recommended dose is 15mg twice daily for days 1-21, then 15mg once daily thereafter. For patients at extremes of body weight (<50kg and >120kg) please seek the advice of the local anticoagulation team. N.B. Rivaroxaban is not recommended if the patient s creatinine clearance is less than 30ml/min due to increased risk of drug accumulation 6. Patients who develop acute renal failure should discontinue rivaroxaban. Creatinine clearance must be calculated (see here for calculator), egfr is NOT considered a suitable alternative. Ratified by Notts APC:November 2012 Review date: November 2015 Page 1 of 5

2 Duration of treatment The duration of treatment will depend on the indication for rivaroxaban and individual patient factors. The usual duration of therapy for DVT or PE is 3 to 6 months, though some patients warrant long-term anticoagulation. For patients with DVT secondary to intravenous drug injection it is usual to treat with rivaroxaban or LMWH for a shortened duration of 3 months. The intended duration of therapy will be advised by secondary care on discharge. It is acceptable for the GP to stop therapy once the treatment course has been completed without re-referral to secondary care. Relevant Contraindications Creatinine clearance less than 15ml/min Clinically significant active bleeding Acute bacterial endocarditis (risk of haemorrhagic transformation of cerebral emboli) Active major bleeding and conditions with a high risk of uncontrolled haemorrhage, including recent haemorrhagic stroke. Active gastric or duodenal ulceration Allergy to rivaroxaban or any of the tablet excipients 1 Patients with hepatic disease associated with coagulopathy and clinically relevant bleeding risk including cirrhotic patients with Child Pugh B and C 1 Pregnancy and breast feeding 1. Women of child-bearing potential should avoid becoming pregnant during treatment with rivaroxaban (animal studies have shown reproductive toxicity) 1 Precautions Increased potential risk for bleeding As for any patient receiving anticoagulant therapy, in the event of any trauma (especially to the head), referral to the Emergency Department (ED) should be considered. Adverse Effects Common side effects reported include anaemia, dizziness, headache, syncope, eye haemorrhage, tachycardia, hypotension, haematoma, epistaxis, gastrointestinal haemorrhage, gastrointestinal and abdominal pains, dyspepsia, nausea, constipation, diarrhoea, vomiting, pruritus, rash, bruising, urogenital tract haemorrhage, fever, peripheral oedema, fatigue, weakness, increase in liver transaminases, post procedural haemorrhage Hepatic side effects Transient elevation of liver transaminases may be seen, as with LMWH. This is usually reversible on discontinuation. Haemorrhage Refer patient immediately to the Emergency Department (ED) if serious bleeding occurs e.g. GI bleeding, epistaxis lasting more than 1 hr Refer patient immediately to the Emergency Department (ED) for investigation if there is any unexplained fall in haemoglobin or blood pressure In the clinical studies mucosal bleedings (i.e. epistaxis, gingival, gastrointestinal, genito-urinary) and anaemia were seen more frequently during long term rivaroxaban treatment compared with VKA treatment. Thus, in addition to adequate clinical surveillance, laboratory testing of haemoglobin/haematocrit could be of value to detect occult bleeding, as judged to be appropriate. 1 Ratified by Notts APC:November 2012 Review date: November 2015 Page 2 of 5

3 Invasive procedures and surgical intervention (a guideline is available within secondary care for the management of these patients): Stop rivaroxaban at least 24 hours before intervention. Measure INR or Xa and if normalised proceed. If procedure cannot be delayed the increased risk of bleeding should be assessed against the urgency of the intervention. For emergency surgery octaplex may be administered and check clotting normalised. Rivaroxaban should be re-started as soon as possible after the procedure provided adequate haemostasis has been established. Reversal or overdose (a guideline is available within secondary care for the management of these patients): There is no specific reversal agent and as yet there is very little clinical evidence or experience in humans on the reversal of rivaroxaban. Measure INR using neoplastin for the assay or the commercially available assay to measure Xa levels. Unlike warfarin, a prothrombin time may not be fully sensitive to the anticoagulant effect of rivaroxaban. Likewise an INR will not demonstrate the level of anticoagulation. Clinically relevant medicine interactions and their management Rivaroxaban is metabolised by CYP3A4 or P-gp and should be used with caution in combination with inhibitors or inducers of these (e.g. clarithromycin, rifampicin). Agents which affect haemostasis (e.g NSAIDS, antiplatelets, prasugrel, clopidogrel, GPIIb/IIIa receptor antagonists, vitamin K antagonists, heparin) should be reviewed and consideration given to their discontinuation prior to rivaroxaban therapy. If the combination cannot be avoided, rivaroxaban should be used with careful monitoring. Azole-antimycotics (e.g. ketoconazole, itraconazole, voriconazole and posaconazole) - plasma concentration of rivaroxaban increased - avoid concomitant use. 1 Fluconazole is a moderate inhibitor of CYP3A4 and appears to only slightly increase rivaroxaban exposure. The UK manufacturer recommends caution on concurrent use, but that this increase is not considered clinically relevant 1. No additional precautions are necessary on concurrent use 6. Discuss with specialist if long term use of fluconazole is anticipated HIV Protease inhibitors (e.g. Ritonavir) - plasma concentration of rivaroxaban increased manufacturer of rivaroxaban advises avoid concomitant use with all protease inhibitors 1,7 Rifampicin plasma concentration of rivaroxaban decreased by rifampicin. The concomitant use of rivaroxaban with other strong CYP3A4 inducers (e.g. phenytoin, carbamazepine, phenobarbital or St. John's Wort) may also lead to reduced rivaroxaban plasma concentrations 1. Consider use of an alternative drug to avoid this interaction. 6 If this is not possible, contact specialist for advice. Ratified by Notts APC:November 2012 Review date: November 2015 Page 3 of 5

4 Monitoring requirements Clinical trials have demonstrated that the therapeutic anticoagulation effect of rivaroxaban does not require routine monitoring. As such regular INR tests are not required. Unlike warfarin, a prothrombin time may not be sensitive to the anticoagulant effect of rivaroxaban. Likewise an INR will not demonstrate the level of anticoagulation. As approximately a third of the active drug is eliminated by the renal route, it is prudent to monitor the renal function of a patient taking rivaroxaban. The following regimen is in line with NICE guidance on Chronic Kidney Disease and based on consensus clinician opininon. Should the individual patient be deemed at a greater risk of developing renal dysfunction, more frequent monitoring may be warranted: U + Es (Creatinine clearance) Baseline tests to be done by secondary care Full blood count Coagulation screen Liver function tests U+Es will also be done on day 7 and day 21 in secondary care Follow up monitoring tests to be done by primary care U + Es Full blood count Coagulation screen Liver function tests (Creatinine clearance) * Renal function monitoring frequency Creatine Clearance of patient Frequency of renal function monitoring >60ml/min Annually 30-60ml/min Six Monthly The exact frequency should depend on the clinical situation. The frequency of testing will need to be increased if there is rapid progression, or during intercurrent illness and perioperatively in all patients with CKD. 7 * see Haemorrhage section above Creatinine clearance must be used for calculating renal function for this agent; due to the risks associated with a patient taking an inappropriate dosage (egfr is NOT a suitable alternative). The patient s Creatinine Clearance should be calculated using the Cockroft & Gault equation (see below or click here for calculator): (140 age) x weight (kg) x 1.04 (female) or 1.23 (male) serum creatinine (micromol/l) Ratified by Notts APC:November 2012 Review date: November 2015 Page 4 of 5

5 Criteria for review and discontinuation of the medicine Side Effect Haemorrhage Excessive bruising (eg. bruises larger than a palm or purpura on the palate) Any acute illness that MAY effect renal function Significant reduction in renal function If creatinine clearance falls to below 15ml/min Action Refer patient immediately to ED if serious bleeding occurs eg GI bleeding, epistaxis lasting more than 1 hr Seek immediate haematologist advice Measure U+Es and calculate creatinine clearance. Reduce dose or withhold treatment if required. Consider seeking advice regarding restarting treatment from the local anticoagulation service Reduce dose to 15mg once daily if calculated Creatinine Clearance < 50ml/min (see below for calculation). If renal function continues to worsen discuss with haematologist. Discuss with specialist if Creatinine Clearance falls below < 30ml/min Stop rivaroxaban, assess for bleeding and seek advice as to whether specific assays are indicated / alternative anticoagulation required Information given to patients (secondary care) Patients should be counselled on the risks and benefits of their treatment where appropriate. The patient should be told the indication for rivaroxaban, intended duration and advised of what side effects to look out for. Cost and availability Rivaroxaban is available in 15mg or 20mg tablets. 10mg tablets are not licensed for use in SPAF treatment, and therefore should not be used. Continuing treatment of 20mg once daily costs per 28 days. References 1. Xarelto Summary of Product Characteristics. Last updated on 18/06/ NUH guideline. Rivaroxaban for long term anticoagulation as a substitute for warfarin. July SFHT guideline. Management of Venous Thromboembolism (VTE) for In-Patients. May NICE Clinical Guideline 144: Venous thromboembolic diseases: the management of venous thromboembolic diseases and the role of thrombophilia testing. June BNF 63. March Available from focused update of the ESC Guidelines for the management of atrial fibrillation (An update of the 2010 ESC Guidelines for the management of atrial fibrillation) European Heart Journal 2012;33: available from: 7. NICE Clinical Guideline 73: Chronic Kidney Disease. September 2008 Authors Dr Gerry Dolan, Consultant haematologist, Nottingham University Hospitals NHS Trust (NUH) James Sutton, Specialist Interface and Formulary Pharmacist, Notts APC Julian Holmes, Specialist Clinical Pharmacist (Haemostasis and Thrombosis), NUH Dr Tim Moorby, Consultant Haematologist, Sherwood Forest Hospitals NHS Trust Jenni Hatton. Lead Anticoagulation pharmacist, Sherwood Forest Hospitals NHS Trust Contact details NUH Anticoagulation service: Helpline - (0115) SFH Anticoagulation service: King s Mill Hospital - (01623) Newark Hospital - (01636) Ratified by Notts APC:November 2012 Review date: November 2015 Page 5 of 5