perinatology.com
   OBPharmacopoeia


Home > Reference > OBPharmacopoeia TOC-Public Thromboprophylaxis

THE INFORMATION IN THE OBPHARMACOPOEIATM IS INTENDED SOLELY FOR USE BY THE MEDICAL PROFESSION. IT IS NOT INTENDED FOR LAY PERSONS.

FOCUS INFORMATION TECHNOLOGY, INC. DOES NOT ASSUME ANY RESPONSIBILITY FOR ANY ASPECT OF HEALTHCARE ADMINISTERED WITH THE AID OF THIS CONTENT. THE PRESCRIBING PHYSICIAN MUST BE FAMILIAR WITH THE FULL PRODUCT LABELING AS PROVIDED BY THE MANUFACTURER AND RELEVANT MEDICAL LITERATURE PRIOR TO USING THE OBPHARMACOPOEIATM .


Thromboprophylaxis

Background

The incidence of VTE is reported to be from 0.6 to 1.3 episodes per 1,000 deliveries.
Risks of pharmacological (heparin-induced thrombocytopenia, bleeding, and osteoporotic fracture) or mechanical prophylaxis must be weighed against this risk of VTE [2].

The American College of Chest Physicians (ACCP) recommends that acutely ill medical patients admitted to hospital who are confined to bed and have one or more additional risk factors have thromboprophylaxis with LMWH, LDUH, or fondaparinux [6]. LMHW is the preferred agent during pregnancy [2]. ACCP recommends mechanical methods of thromboprophylaxis be used primarily in\ patients at high risk for bleeding, or as an adjunct to anticoagulant-based thromboprophylaxis [6].


Monitoring
While the risk for HIT has been considered to be low with the use of LMWH [7], there is some evidence that periodic monitoring of patient’s platelet count while on LMWH may be warranted [8]. “Renal function should be considered when making decisions about theuse and/or the dose of LMWH Evaluation of renal function is indicated with the use of LMWH “[6].

 

See also

The Pregnancy and Thrombosis Working Group recommends no pharmacological  thromboprophylaxis antepartum or postpartum for patients with the following thrombophilias who have NO history of venous thromboembolism (VTE) and NO history of adverse pregnancy outcome (APO) unless there are other reasons for providing VTE prophylaxis such as cesarean delivery.

  • Factor V Leiden heterozygote
  • Prothrombin G20210A heterozygote
  • Antiphospholipid antibodies
  • Protein C deficiency
  • Protein S deficiency
  • Hyperhomocysteinemia

Antepartum [6]

Patients admitted to antepartum for PROM, preeclampsia , pyelonephritis or other disorders are often at bedrest for 3 days or more. Because pregnancy itself is an additional risk factor for VTE [6] The combination of confinement to bedrest and pregnancy are sufficient reason to provide VTE prophylaxis.
 

Antepartum prophylaxis dose unfractionated heparin (UFH) or low molecular weight heparin (LMWH) IS recommended for :

  • A history of :
    • A single VTE event with transient risk factor no longer present (clinical surveillance)
    • A single idiopathic episode of VTE not receiving long term anticoagulants.
    • A single episode of VTE pregnancy or estrogen related
    • VTE with family H/O VTE
    • VTE with the following thrombophilias [1-3]:
      • Factor V Leiden heterozygote
      • Prothrombin G20210A heterozygote
      • Protein C deficiency
      • Protein S deficiency
      • Hyperhomocysteinemia
    • Two or more episodes of VTE
  • Antiphospholipid syndrome without history of VTE
  • Thrombophilia with adverse pregnancy outcomes (two or more pregnancy early  losses, one or more late pregnancy losses,  preeclampsia, intrauterine uterine growth restriction (IUGR), or abruption [2].

Antepartum adjusted dose UFH or LMWH IS recommended for :

  • Thrombophilias with or without H/O VTE [1-3]:
    • Factor V Leiden homozygote
    • Prothrombin G20210A homozygote
    • Antithrombin III deficiency
    • Compound heterozygote of Factor V Leiden and Prothrombin G20210A
  • Antiphospholipid antibodies with H/O VTE [2,3]
  • Active arterial and or venous embolism [1]
  • Multiple (two or more) episodes of VTE and/or women receiving long-term anticoagulants (e.g., single episode of VTE—either idiopathic or associated with thrombophilia) [1-3]

  • History of rheumatic heart disease with current atrial fibrillation [2]
  • Patients with Mechanical Heart Valves [2]
    • "Adjusted-dose, twice-daily LMWH throughout pregnancy in doses adjusted either to keep a 4-hour postinjection anti-Xa heparin level at approximately 1.0 to 1.2 U/mL (preferable) or according to weight OR
    • Aggressive adjusted-dose UFH throughout pregnancy: i.e., administered SC every 12 hours in doses adjusted to keep the mid-interval aPTT at least twice control or to attain an anti-Xa heparin level of 0.35 to 0.70 U/mL  OR
    • UFH or LMWH (as above) until the thirteenth week, change to warfarin until the middle of the third trimester, and then restart UFH or LMWH .
    • In women with prosthetic heart valves at high risk low-dose aspirin, 75 to 162 mg/day ."

Intrapartum

  • Discontinue prophylactic LMWH 12 hours before scheduled induction of labor  or cesarean delivery.
  • Discontinue full dosing LMWH 24 hours before scheduled induction of labor or cesarean delivery.
  • Where delivery is anticipated LMWH heparin should be stopped if spinal or epidural anesthesia is to be used. “Insertion of a spinal needle or epidural catheter should be delayed until the anticoagulant effect of the medication is minimal.. This is usually at least at least 18 h after a once-daily prophylactic dose of LMWH.   Consult anesthesiologist.
  • Use pneumatic compression devices intrapartum, and continue until the patient is fully ambulatory.

 

Postpartum [1,6]

  • Removal of an epidural catheter should be done when the anticoagulant effect of the thromboprophylaxis is at a minimum (usually just before the next scheduled subcutaneous injection). Anticoagulant thromboprophylaxis should be delayed for at least 2 h after spinal needle or epidural catheter removal.”[6]
  • Patients who undergo cesarean delivery with thrombophilias without a history of VTE or WITH a history of adverse pregnancy outcome (APO) should receive prophylactic UFH or LMWH for 6 weeks postpartum [1].
  • Patients on prophylactic LMWH or UFH for VTE  should continue on the same dose for 6 weeks  postpartum.
  • Patients on adjusted dose of UFH or LMWH can be restarted on heparin and warfarin 5 mg concurrently. Adjust the warfarin dosage according to pharmacy protocols [5]. Do not discontinue heparin until  INR has been therapeutic for at least 2 days [1]. Therapeutic anticoagulation is usually achieved in 5 to 7 days, but may take longer.
  • Obtain hematology consultation for patients on long term anticoagulation .

Low–dose UFH (porcine) prophylaxis [3]:
Check platelet count at the start of treatment, on day 4 of therapy, and then every 2 to 3 days for first two weeks and then at 3 weeks in patients who have received UFH [1,4]. See heparin induced thrombocytopenia (HIT)

  • Mini-dose UFH [1]: UFH 5,000 U subcutaneous (SC) every 12 hours
  • Moderate-dose UFH[1]: UFH SC every 12 hours in doses adjusted to target an anti-Xa level of 0.1 to 0.3 U/mL
  • 5,000–7,500 U every 12 hours during the first trimester
                    7,500–10,000 U every 12 hours during the second trimester
                    10,000 U every 12 hours during the third trimester unless the APTT* is elevated. The APTT may be checked near term and the heparin dose reduced if prolonged OR
  • 5,000–10,000 U every 12 hours throughout  pregnancy .

Low–dose LMWH prophylaxis [3]:
For prophylaxis Anti factor Xa peak range (3-4 hours after dosing) is  0.2-0.4 IU/ mL
Trough (12 hours after dosing) 0.1 - 0.3 IU/mL [1].

  • Prophylactic LMWH [1]:
    dalteparin (Fragmin) 5,000 U SC every 24 hours or
    enoxaparin (Lovenox) 40 mg SC every 24 hours
    (although at extremes of body weight modification of dose may be required)
     
  • Intermediate-dose LMWH[1]:
    dalteparin 5,000 U SC every 12 hours, or
    enoxaparin
     (Lovenox) 40 mg SC every 12 hours
     

Pharmacy to adjust dose for weight greater than 100 kg
Renal disease - Pharmacy to adjust dose as follows if CrCl less than 30 mL/min


Adjusted dose UFH (porcine) [3]
Check platelet count at the start of treatment, on day 4 of therapy, and then every 2 to 3 days for first two weeks and then at 3 weeks in patients who have received UFH  [1,4]. See heparin induced thrombocytopenia (HIT)

UFH SC every 8 to 12 hours
Adjusted to prolong the activated partial thromboplastin time (aPTT) to 1.5 - 2.5 times the control when tested at mid-interval between subcutaneous injections.

Adjusted-dose LMWH :
For treatment antifactor Xa target peak range (3-4 hours after dosing) is 0.5 - 1 IU/mL (upper range  0.8-1 IU/mL) [1]
Trough (12 hours after dosing) 0.2 - 0.4 IU/mL (>0.5 IU/mL for highest risk)  [1].

Weight-adjusted, full-treatment doses of LMWH.
Dalteparin 100 U/kg every 12 hours or
Enoxaparin
 (Lovenox) 1 mg/kg every 12 hours.

Pharmacy to adjust dose for weight greater than 100 kg
Renal disease - Pharmacy to adjust dose as follows if CrCl less than 30 mL/min
 


REFERENCES

1. Duhl AJ et. al Antithrombotic therapy and pregnancy:consensus report and recommendations for the prevention of venous thromboembolism and adverse pregnancy outcome. Am J Obstet Gynecol 2007;197:147.e1-457.e21 PMID:17980177

2.Bates SM, Greer IA, Hirsh J, Ginsberg JS. Use of antithrombotic agents during pregnancy: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy.Chest. 2004;126(3 Suppl):627S-644S PMID:15383488

3. ACOG practice bulletin. Thromboembolism in pregnancy. Int J Gynaecol Obstet. 2001 ;75(2):203-12. PMID:11724031

4. Warkentin TE , et al. Heparin-Induced Thrombocytopenia: Recognition, Treatment, and Prevention.The Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 2004; 126:311S-337S PMID:15383477  

5. Kovacs MJ, Rodger M, Anderson DR, Morrow B, Kells G, Kovacs J, Boyle E, Wells PS.Comparison of 10-mg and 5-mg warfarin initiation nomograms together with low-molecular-weight heparin for outpatient treatment of acute venous thromboembolism. A randomized, double-blind, controlled trial. Ann Intern Med. 2003 May 6;138(9):714-9. PMID:12729425

6. Geerts WH, et al. Prevention of venous thromboembolism: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition).Chest. 2008 Jun;133(6 Suppl):381S-453S.PMID: 18574271

7. Martel N, et . al. Risk for heparin-induced thrombocytopenia with unfractionated and low-molecular-weight heparin thromboprophylaxis: a meta-analysis.
Blood. 2005 Oct 15;106(8):2710-5. Epub 2005 Jun 28.
PMID: 15985543

8. Prandoni P, et al. The incidence of heparin-induced thrombocytopenia in medical patients treated with low-molecular-weight heparin: a prospective cohort study. Blood. 2005 Nov 1;106(9):3049-54. Epub 2005 Jul 19. PMID: 16030191

 

Home | About | Disclaimer | Privacy | Contact
Copyright © 2009 by Focus Information Technology.
All rights reserved