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Date of last update: 10/12/2017.

Forum Name: Hematology Topics

Question: How long can you safely take LMWH?

 2blessings - Sat Jul 17, 2010 12:35 pm

Taking Low Molecular Weight Heparin for 6 months, via injection on determination by doctor. Now I have learned I will need to be on lifetime anticoagulants. I do not want to take Coumadin/Warfarin. How long can a patient safely stay on LMWH, like Fragmin/Lovenox? I know there is a risk of Osteopenia, but what determines the length of safe treatment with LMWH?
 Dr.M.Aroon kamath - Tue Aug 03, 2010 11:26 am

User avatar Hi,
Before i try to address the question as to “what determines the length of safe treatment with LMWH ?, i would prefer to answer the question “who determines the length of safe treatment with LMWH”.

For the first time, the FDA approved a new indication for FRAGMIN(R) (dalteparin sodium injection), for the extended treatment of symptomatic venous thromboembolism (VTE) [proximal deep vein thrombosis (DVT) and/or pulmonary embolism (PE)] to reduce the recurrence of VTE in patients with cancer.
FDA approval was based on data from the landmark CLOT study (N Engl J Med 2003; 349:146-153July 10, 2003), which evaluated the safety and efficacy of FRAGMIN in reducing the recurrence of DVT/PE in patients with cancer, compared to an oral anticoagulant (warfarin).
The study period lasted 6 months.

Although four different types of brand name LMWH products had been already approved by the (US) FDA, no generic versions of these drugs had been approved in the United States till July 23, 2010, at which time, the FDA approved the first generic LMWH “Lovenox” (enoxaparin sodium injection) for use as an anticoagulant therapy.

(Although long-term warfarin therapy had so far been the mainstay of treatment for cancer patients with VTE, there are many practical problems with its use in this group. In particular, achieving therapeutic drug levels is a challenge in cancer patients due to the increased risk of malnutrition, vomiting, drug interactionsand liver dysfunction in these patients. Moreover, these patients are at an increased risk of adverse effects of warfarin therapy. In contrast, LMWHs are associated with a lower risk of adverse events compared with warfarin in these patients. These agents also possess practical advantages compared with warfarin, including more predictable anticoagulant activity and ease of administration).

LMWH is administered once or twice daily, both during the high-risk period when prophylaxis for DVT is recommended and also while waiting for oral anticoagulation to take effect in the treatment of DVT. The activated partial thromboplastin time (aPTT) does not need to be monitored, and the dosage does not need to be adjusted. LMWH is already approved for use in outpatient settings(including management at home) for these short term indications.

Now let me try to answer the question “what determines the length of safe treatment with LMWH ?

The possible determinants are,
- results from long term, well designed randomized trials indicating efficacy and safety, and of course,
- final approval from agencies such as the (US) FDA as well as others, and
- long term post marketing surveillance.

I hope this information is helpful to you.
Best wishes!

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