Anticoagulation

1. Anticoagulation Presented by KENNY ALEXANDER, PharmD SLMV Pharmacy Clinical Coordinator

2. Objectives • Review the pharmacology, indications, dosing, adverse effect profiles of heparin, low molecular weight heparins, Coumadin • Gain an understanding of St. Luke’s policies regarding dosing and administration of anitcoagulation therapy • Understand nursing care as pertains to patient on anticoagulation therapy

3. Unfractionated vs. LMWH (Heparin) (Lovenox) • Natural polysaccharide-various chain sizes • Derived from animal tissues • Discovered in 1916 • Genetically cleaved-short chains

4. Heparin-inhibits coagulation Indications • VTE (venous thromboembolism) treatment • VTE prophylaxis • Acute MI • Unstable angina • Coronary intervention (PTCA, stenting) • Atrial fibrillation • Non-hemorrhagic stroke • Line flushing (low dose)

5. Heparin • Rapid onset of action • Half-life about 1.5 hours • Administered IV or SC (never IM) • Lab monitoring: PTT(aPTT) (activated partial thromboplastin time), CBC, ACT (activated clotting time) • aPTT should be measured 6 hours after bolus or dose change IV only (Short half life, 6 hours = 4 half lives)

6. Heparin dosingprophylaxis vs. treatment • Prophylaxis: 5,000-10,000 units SQ q 8-12 hours (no need to check aPTT) • Treatment doses IV: • Coronary/Regular nomogram: 5,000 unit bolus IV, then 1000 unit/hr IV infusion, doses adjusted by aPTT results • Weight based nomogram (DVT/PE): 80units/kg IV bolus, then 18units/kg/hr IV infusion, doses adjusted by aPTT results

7. RN Responsibilities • Obtain initial and daily weights (wt-based) • Obtain baseline aPTT, PT, and CBC • Second RN verification: • order calculations • bolus dose (given IV push only) • IV settings • Hang via Guardrails (cont. next slide)

8. RN Responsibilities • Order timed aPTT 7 hours after bolus and every infusion rate change, then daily (after 2 consecutive therapeutic aPTT) • Monitor for signs of bleeding • Educate patient on risks/treatment

9. Heparin: influencing factors • Minor to major • Certain factors increase risk • Concurrent use of antiplatelet drugs • Higher doses of heparin • Concurrent cardiac, renal, liver disease, ETOH • Increase age • Supratherapeutic aPTT

10. Heparin: adverse reactions • Heparin induced thrombocytopenia (HIT): Type I, Type II • Bleeding • Rarely: • Fever • Headache • Hyperkalemia • N/V/constipation • Conjunctivitis

11. Heparin Induced Thrombocytopenia (HIT) • 1-2% of patients receiving unfractionated heparin have a fall in platelets of 50%. • Majority of cases of thrombocytopenia, stop heparin and platelets return (Type I) • About 0.1% - 0.2% of patients develop immune thrombocytopenia mediated by IgG which can lead to thrombosis. (Type II)

12. Treatment Bleeding • Reversal agent-IV protamine HIT treatment • Stop heparin • If you still need anticoagulation can use • Refludin (lepirudine) • Argatroban (if patient has renal failure) • LMWH can also cause HIT

13. Low Molecular Weight Heparin (LMWH) • Lovenox • Longer acting • more consistent dose response • better SC absorption • May be more effective for some indications and cause less bleeding than heparin • Higher dose used to treat active thrombotic disease, lower dose to prevent thrombosis

14. Contraindications to UFH/LMWH • Active bleeding • Hemophilia • Severe liver disease with elevated PT • Severe thrombocytopenia • Malignant hypertension • Inability to monitor treatment • Hypersensitivity to UFH/LMWH • Previous history of HIT

15. Enoxaparin (Lovenox) • Indications: • DVT/PE treatment • DVT/PE prophylaxis • Acute coronary syndromes (prevention of ischemic complications of unstable angina and non Q-wave MI when given concurrently with aspirin) • Embolic stroke

16. Enoxaparin Treatment • DVT/PE treatment: 1mg/kg SC q 12 hours or for inpatients 1.5mg/kg SC qd • Unstable angina/Non Q wave MI: 1mg/kg q 12 hours Prophylaxis • Medical prophylaxis: 40 mg SC QD • Hip or knee: 30mg SC Q 12 hours or 40mg SC qd for hip surgery • Abdominal surgery: 40mg SC QD

17. Enoxaparin Bariatric Population considerations: • 1mg/kg (actual body weight), up to 120kg then consider dosing with an adjusted body weight. • Patients > 150kg consider using unfractionated heparin which can be monitored. Anti Xa levels may be useful in certain circumstances (draw 4 hours after dose)

18. Enoxaparin • Pharmacokinetics: • Renally eliminated • Onset of action: 30 minutes • Peak levels: 3-5 hours • Half-life: 4.5 hours

19. Enoxaparin • Laboratory Monitoring • aPTT not necessary • CBC (Platelets) • Creatinine for dosing adjustments prn • Adverse effects • Bleeding • Bruising • Blood in urine/stool/vomit

20. Enoxaparin/Lovenox • Patient Teaching Kits for home use • Kit contains patient education brochure & video • Lovenox reimbursement hotline/assistance program available for discharged patients

21. Administration-Heparins • SQ administration in belly tissue • Alternate administration sites • Further away from umbilicus • Pinch hold, have syringe at 90 degree angle to administer, don’t release air bubble prior to injection

22. Epidurals • Epidurals: risk of spinal hematoma • Do Not administer anticoagulants except SQ Low Dose Heparin • Call Pharmacy to verify • Surgeon may order and not realize epidural still in • Warning in MAK epidural dose regarding anticoagulation • Monitor site closely hematoma

23. Coumadin (warfarin) • Oral dosing only • Used for short or long term • Treatment of VTE • Prophylaxis a-fib • Prophylaxis w/ mechanical valve • Cardiomyopathy • CVA prevention

24. Coumadin Dosing

25. Coumadin • Used in conjunction with Heparin/ Lovenox while achieving therapeutic dose • Requires routine monitoring for therapeutic levels • PT (Protime)/INR (International Nomalized Ratio) • Effects on vitamin K

26. Coumadin • Monitored with PT (Protime)/INR International normalized ratio • Dose adjusted per lab value by MD or Pharmacist if asked • Therapeutic level reached 3-7 days • Therapeutic • PT/INR • 20-30/2.0-3.0 (prefer higher end for mechanical valves)

27. Coumadin-RN Responsibility • Patient Education • diet, medication interactions, lab tests, safety precautions, monitoring bleeding precautions • Provided by Video, brochure, RN, Pharmacist, Dietician • Monitor Lab values • CBC, PT/INR • Educate patient on daily monitoring • Implement Fall Risk Precautions if INR >4.0 • Administer @ 1700 unless ordered otherwise

28. Coumadin • Supratherapeutic • Reversal with Vitamin K oral or injection • Fresh Frozen Plasma • Monitor patient carefully for bleeding and safety

29. SLMV VTE Prophylaxis Orders

30. Case Study 1 • 33 y/o female comes to ED in outlying hospital c/o left pelvic pain. Patient receives a pelvic exam, found positive for ovarian cyst sent home with Norco. • Next morning 0300 patient returns to ED in Magic Valley with c/o chest tightness, states pelvic pain is better. History is benign, only noted medication is oral contraceptives. Patient is non-smoker, occasional drinker. Patient also states multiple long car trips of the last month. • What can we expect?

31. Case Study 1 • Pt is given cardiac work-up with ECG, enzymes which are negative. CT pulmonary angiogram and LE Doppler. • CT pulmonary angiogram is positive for bilateral PE’s • Doppler positive for LLE DVT extending high into groin area w/ decrease flow to right leg • What is the expected course of action for this patient?

32. Case Study 1 • Treatment is for known PE/DVT’s expect weight based Lovenox to start immediately. Weight is 94kg. • Patient education on home use • Then start on Coumadin for long term treatment, minimum 6 months to therapeutic PT/INR. • Patient education by pharmacy • Nursing education on precautions • INR 0.8-1.2 PT 12-15 seconds (goal: INR 2-2.5/PT 20-30 seconds) • Patient education on importance of lab

33. Case Study 2 • 78 y/o male with history of RLE DVT 2 months ago admitted with increased scrotal edema, renal insufficiency and BLE edema worse in the right. Lab work reveals elevated BNP 447, H&H 7.3 & 22.3, BUN 40 Cr 3.6, INR 4.42/PT 43. • Patient has extensive history: htn, diabetes w/ neuropathies, elevated PSA, • What are your concerns?

34. Case Study 2 • Elevated INR/PT • Decreased H&H • Elevated BNP • Elevated Bun/CR • What else? • What’s going on?

35. Case Study 2 • Patient has been treated for DVT’s which have a 70% likely hood of PE’s also. • Renal insufficiency leads to elevated PT/INR • INR is supratherapuetic, clots take time to dissolve. PE’s have lead to increased right sided heart pressure leading to right sided heart failure backing up into the venous system as evidence by LE edema. • Decreased blood flow to left side of heart therefore decreased perfusion to kidneys in a patient with likely Diabetes injured kidneys. Also patient’s decreased renal will decrease erythropoietin and increased circulating volume will cause dilution to H&H. • Patient may also have a bleed: (Guiac negative) • Patient’s Coumadin was held for two days, INR/PT 2.8 & 27, lasix 120mg given on admit & 40mg q6h, bun/cr stable at 3.2 & 36, H&H 8.0 & 24.8 on day two. 2 un PRBC ordered.