Procedure for the prescribing and administration of Low Molecular Weight Heparins

Transcription

1 Procedure for the prescribing and administration of Low Molecular Weight Heparins Author: Lilian Baxendale Designation: Pharmacist Version: 1c Date: March 2013 Date Approved: 17 th May 2013 Approved By: Drugs and Therapeutics Committee (Physical Health) Lead Director: Sharon Binyon Review Date: May 2015 Name of responsible Drugs and Therapeutics Committee committee / individual: Target Audience: Page 1 of 5

2 1. Introduction and Background Low molecular weight heparins (LMWHs) (bemiparin, dalteparin. enoxaparin, tinzaparin) are used in the prevention and treatment of venous thromboembolism (VTE) and treatment of acute coronary syndromes. In the UK, LMWHs are considered the treatment of choice as they offer many advantages over regular unfractionated heparin. A standard dosing regimen is used when LMWHs are used in the prevention of VTE. The dose for treatment of a thromboembolic event is dependent on the weight of the patient. Underdosing can lead to an increased risk of a further thromboembolic event, while overdosing can increase the risk of bleeding, leading to serious consequences for the patient. Between January 2005 and September 2009, the NPSA received 2,716 patient safety incident reports relating to dosing errors concerning LMWHs. These include one incident reported to have led to death and three reports of severe harm. A review of NHS Litigation Authority claims identified one further death. The NPSA issued an alert in July 2010 Reducing treatment dose errors with low molecular weight heparins. This alert made various recommendations to reduce the risk to patients when LMWHs are prescribed and administered. 2. Purpose The purpose of this procedure is to ensure the safe prescribing and administration of LMWHs within the Trust. All activities carried out in relation to this procedure should be delivered in a nondiscriminatory manner and respect the individuality and diversity of the patient. 3. Linked Documents This procedure should be read in conjunction with other related Trust policies and procedures, including the Medicines Policy, Injectable Policy, Procedure for the use of Anticoagulants, Policy for Standard Infection Control. 4. Responsibility All staff involved with the prescribing and administration of LMWHs are responsible for ensuring that they are aware of and understand this procedure and are aware of their responsibilities and accountabilities as laid down within their professional code of conduct. Page 2 of 5

3 Prescribing of LMWHs 1. Prescribers must ensure that the dose of LMWH that they are prescribing is the correct dose for the indication. An accurate weight (in kilograms) should be obtained at the start of therapy and where applicable during treatment (i.e. if treatment with LMWH is for a prolonged time period). This weight should be documented on the prescription/administration sheet and in the medical notes. 2. The prescribed dose should be written on the prescription/administration sheet, together with the indication (e.g. treatment of VTE, prevention of VTE). The dose should be written in both units and volume (ml). The treatment length or review date should be stated on the prescription/administration sheet. 3. Renal function should be checked. The risks of adverse effects (i.e. bleeding) from LMWHs is significantly increased in patients with renal impairment. Caution is required when using any LMWH in patients with any degree of renal impairment, especially those with a creatinine clearance of <30ml/min.The first dose of LMWH for treatment of VTE should not be delayed whilst waiting for renal function results; however, the dose should be reviewed on receipt of results and adjusted as necessary. 4. Routine monitoring of anti-factor Xa (anti-xa) activity is not usually required during treatment with LMWHs, although it may be necessary in patients at increased risk of bleeding, such as those with renal impairment and those who are underweight or overweight. 5. Heparin can suppress adrenal secretion of aldosterone leading to hyperkalaemia. Plasma potassium should be measured in patients at risk (e.g. those with diabetes mellitus, chronic renal failure, pre-existing metabolic acidosis, raised plasma potassium or taking potassium sparing drugs) before starting LMWH therapy and monitored regularly (on day 4 of treatment and weekly thereafter). The LMWH should be stopped if hyperkalaemia develops. 6. As there is a risk of antibody-mediated heparin-induced thrombocytopenia occurring with LMWHs, regular platelet count monitoring should be considered prior to and during therapy every 4 days for the first 14 days of treatment with these agents. Antibodymediated heparin-induced thrombocytopenia is most likely to occur between the 5 th and 21 st day after therapy is started. If a significant decrease of platelet count is observed (30-50% of the initial value) the LMWH should be immediately discontinued and the patient switched to another therapy. 7. The prescription should be regularly reviewed to ensure that therapy with LMWH is still indicated, and whether transfer to oral anticoagulant therapy is appropriate. 8. Prescribers should ensure that information such as dose, weight, renal function, indication and duration of treatment is communicated at transfers of care (e.g. by discharge letters). 5. Administration of LMWHs 1. Before administering LMWHs, staff should check that the dose of LMWH is correct for the patient. 2. LMWHs should be administered parenterally by subcutaneous injection into the. anterolateral or posterolateral abdominal wall, alternately on the left or right side for the treatment or prophylaxis of VTE. Page 3 of 5

4 3. The whole length of the needle should be introduced vertically into a skin fold held between the thumb and index finger. The skin fold should not be released until the injection is complete. Do not rub the injection site after administration. 4. Staff should monitor for any adverse effects from the injection (e.g. signs of bleeding, hypersensitivity reaction, injection site reaction) and alert the prescriber with any concerns. An incident form and medicines error form should be completed if appropriate. 5. Following discharge from hospital, the administration time of the LMWH may be moved by a maximum of four hours as a once-only time change to facilitate administration at a convenient regular time by community nurses. The decision to alter the administration time must be confirmed with the relevant prescriber, and the patient informed of the reasons for this alteration, before the LMWH is administered. This is outside the product license and would be an individual patient specific clinical decision. All subsequent doses must be given at 24 hour intervals. The patient will be more at risk of adverse effects e.g. bleeding if the dose interval is shortened and must be monitored for or advised to contact the service if they show any signs of adverse effects e.g. bleeding, bruising. NB LMWH may be available as prefilled graduated syringes, containing different numbers of units of LMWH. The dose required may be less than the number of units contained in the full syringe. 1. Choose the most appropriate sized syringe e.g. for a dose of 85mg enoxaparin, the 100mg enoxaparin syringe should be chosen. 2. Expel the excess from the syringe before administration. For enoxaparin, point the needle downwards and press the plunger until the correct dose is reached For tinzaparin, point the needle upwards and press the plunger until the correct dose is reached 3. Within the bedded facilities, another responsible person (e.g. a qualified nurse) should witness the procedure and double check the syringe before administration to ensure that the correct dose is administered. Within Community Health Services, if this is not possible, single nurse administration may take place. See Medicines Manual and associated Guidance (MMG11). 6. Dispensing Pharmacy/ Medicines Management Team 1. The dispensing pharmacy should a. check that the dose of LMWH is appropriate for the weight of the patient before dispensing (for treatment of VTE) b. contact the prescriber with any concerns, including querying length of treatment course and amount to issue on discharge, if not specifically indicated. 2. Within the bedded facilities On their routine clinical visits, pharmacists and pharmacy technicians from the Medicines Management Team should a. check that the dose of LMWH is appropriate for the weight of the patient (for treatment of VTE) b. check renal function and that the appropriate monitoring (platelet, potassium level) has been undertaken. Page 4 of 5

5 c. contact the prescriber with any concerns, including querying length of treatment course 7. Training/competencies All staff who prescribe for, or administer to, patients requiring LMWH therapy must have training to ensure that they have the necessary work competences for maintaining anticoagulant therapy. An e-learning programme, and a list of the necessary competencies, is available at 8. Dissemination and implementation Once approved, the procedure will be made available on the intranet. Notification of its release will be made via all user s/trust Team Brief for cascade to all staff members. Ward/unit managers will be responsible for its implementation on their areas. 9. Equality Impact An equality impact assessment of this procedure will be carried out prior to ratification. 10. Monitoring Key aspects of his procedure will be audited with regard to compliance, initially annually. 11. References 1. NPSA/2010/RRR014 Rapid Response Report Reducing treatment dose errors with low molecular weight heparins 30th July SPCs bemiparin, dalteparin, enoxaparin, tinzaparin (emc accessed October 2010) Keeling D, Davidson S, H Watson. BJH Guidelines: The management of heparin-induced thrombocytopenia. British Society for Haematology 2006: 133; Brighton and Sussex University Hospitals NHS Trust Shared Care Guideline Tinzaparin (innohep ) in combination with warfarin for the treatment of Venous Thromboembolic disease (DVT/PE) 6. NHS Devon. Clinical Guideline for the use and monitoring of LMWHs in community hospitals and community settings. January communication from Sanofi to Priti Ved 19/3/ communication from O Chapman, Consultant Haematologist, to Mark Easter 8/10/11 Page 5 of 5