LOVENOX and risk of BLEEDING

LEARN FROM SOMEONE ELSE'S MISTAKE PLEASE.

I had a recent case of intracerebal bleed on a patient I took care of in the North Shore. I go to 3-4 hospitals in greater Boston area and the name of the hospital is not important.
If this happened to me who had been jumping up and down on this particular subject, shame on me. So I will share the incidence with the rest of the world.

76 yrs old lady with mild disorientation had normal CT scan head in June. Because of atrial fibrillation she had been on warfarin and Lovenox. She came to us on Lovenox 60 mg bid. We decreased the dose to 40 mgs qd. She weighed, say , 110 lbs.

Her INR ranged between 1.7 and 2.9 most of the time .On two episodes her INR was 4.8, 5.2. She was on daily PT/INR. She had one dose of Vitamin K 5 mgs which improved INR.

She continued to get more and more confused. She had no observed fall or head trauma
Repeat Ct scan head two weeks later showed posterior fossa subdural hematoma.

Looking back her serum creatinine was 1.2 on admission then improved to 0.8 e GFR was 49 initially then 54 and later 60.

My take on this is: Lovenox is risky on patients old people.
Whatever you definition of old is I have no problem with.
Maybe the mechanism is renal insufficiency after all.
All old people have renal insifficiency. No matter what their serum creatinine is.
No matter what the eGFR is they may have renal insifficiency.

Most people do not know eGFR is the GFR of an Ideal American- 5'6" tall weighing 140 lbs. for any particualr age.

The patient in front of you may be 100 lbs , 4'10" or 180 lbs 6 feet tall But the eGFR is the same if they have the same age, sex and race ( white or black). So both serum creatinine and eGFR are misleadingly better than the real renal function .

So I am going to take a position when you are old ? over 60 ? over 70 or whatever you should not use Lovenox at all or use a smaller dose than usual.

The generally accepted Lovenox adjustment of using 30 mgs once a day and no more in renal insufficiency ( defined as GFR less than 30 ml, not eGFR but real GFR) is misleading and does not offer protection in many cases in "old age".

So save some lives please in old age think twice before you use Lovenox.

You would notice I am talking about only Lovenox not all low molecular heparins, as my experience is mostly with Lovenox , by its brand name.

Do not miss the point I am not saying Lovenox is worse than this or that. That is what MDs have to decide themselves. My point is it is not easy to measure Factor Xa or any other labs for Lovenox over dose. Neither serum creatinine nor eGFR gives the real renal function in old people.So we are DOUBLY HANDICAPPED.
YOU DO NOT HAVE TO LEARN THE HARD WAY , LEARN FROM SOME ELSE'S MISTAKE.
Related Thrombosis
General Dosing Guidelines
A. Initial treatment of acute thrombosis:
Enoxaparin 1mg/kg SQ q12h until minimum course of 5 days has been completed and INR is greater than 2.0 (1.5mg/kg q24h may also be used in pts who are not obese [BMI > 27] and who do not have malignancy).
B. Initial anticoagulation in patients with atrial fibrillation, heart valve replacement, LV thrombus, or other cardiovascular indications for anticoagulation:
Enoxaparin 1mg/kg SQ q12h.
C. Bridge therapy during prolonged periods of under anticoagulation:
Enoxaparin 1mg/kg SQ q12h until INR > lower limit of therapeutic range (1.5mg/kg q24h may also be used in patients whose indication for anticoagulation is DVT/PE or other non-cardiovascular indication for anticoagulation, including patients with malignancy).
D. Bridge therapy before and after invasive or dental procedures:
Enoxaparin 1mg/kg SQ q12h initiated when INR <> lower limit of therapeutic range (1.5mg/kg q24h may also be used in patients whose indication for anticoagulation is DVT/PE or other non-cardiovascular indication for anticoagulation, including patients with malignancy).
E. Long term use in place of warfarin:
Enoxaparin 1mg/kg q12h (1.5mg/kg q24h may also be used in patients whose indication for anticoagulation is DVT/PE or other acute non-cardiovascular indication for warfarin, including patients with malignancy).
II. Dosage Adjustments in Obesity
A. Use Total Body Weight (TBW) up to 190kg.
B. If > 190kg:
AntiXa level monitoring available:
Use TBW and adjust dose downward if necessary based on antiXa levels
AntiXa level monitoring NOT available
Use TBW and adjust dose downward if necessary if bleeding occurs
III. Dosing in Renal Impairment
A. If no antiXa monitoring available: Avoid use if CrCl < 30 ml>B. If antiXa monitoring is available, consider the following initial dosing and adjust as necessary based on peak antiXa activity levels:
Clcr > 60: 1mg/kg q12h
Clcr 30-60: 0.85mg/kg q12h
Clcr <> 2.0
Until antiXa level < name="Anchor-Short-37516">IV. Short Term Monitoring Guidelines
A. Platelet count: Every 2 to 3 days during first 14 days of therapy.
B. Peak antiXa activity:
3 to 4 hrs after dose in patients with:
renal impairment (Clcr<> 190kg)
unexpected hemorrhage.
Check after 3rd dose and again if adjustment required.
Goal:
0.5-1.0 U/mL for bid dosing
1.0-2.0 U/mL for qd dosing
C. Trough antiXa activity:
At end of dosing interval
Check before 4th dose and again if adjustment required
Goal: < name="Anchor-Long-23522">V. Long Term Monitoring Guidelines
A. Peak antiXa activity: Check at 7 days, then once monthly.
B. Trough antiXa activity: Check at 7 days, then check once monthly.
C. Scr: Once monthly (routine labs acceptable).
D. Clcr: Calculate monthly (adjust dose as necessary).
E. Patient weight: Check monthly (adjust dose as necessary)
F. Platelets: Once monthly (routine labs acceptable)
G: Hct: Once monthly (routine labs acceptable)
Questions & Comments© 2006, University of Washington Anticoagulation Services.All Rights Reserved.