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The following message was posted to: PharmPK
I am working in CRO, I have one doubt about using of anticoagulant.
Many times we used K3EDTA as anticoagulant. but some drugs it is K2EDTA.
and for some drugs Lithium heparin. What is the main reason using
different types of anticoagulants
any information is helpful for me
with regards,
srinivas
Research Analyst
Bioserve Clinical Research pvt Ltd
Hyderabad.
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The following message was posted to: PharmPK
Well, the only thing I can tell you, from experience, is that high
concentrations of heparin (typically above 100 uL / 10 mL blood) induce
haemolysis. I've tried both heparin and K3EDTA for many purposes
(protein
isolation and neutrophil studies, eg) and I got no difference in the
results. They work both fine provided for that detail.
Goncalo
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Hello,
For some drugs (& prodrugs) containing phosphate ester functional
groups EDTA is preferable since it can protect them from plasma
esterases and phosphatases that require metal ions as cofactors.
Breakdown of drug (& prodrug) in plasma after sample collection can
create artifacts in PK profiles, which can sometimes be simply
prevented by changing the anticoagulant. For drug containing acetate
ester moieties vacutainers containing potassium fluoride can be
helpful. Please see the following references:
1: Samtani & Jusko. Stability of dexamethasone sodium phosphate in
rat plasma. Int J Pharm. 2005; 301:262.
2: Samtani et al. Betamethasone pharmacokinetics after two prodrug
formulations in sheep: implications for antenatal corticosteroid use.
Drug Metab Dispos. 2005; 33:1124.
3: Samtani et al. Stabilization and HPLC analysis of betamethasone
sodium phosphate in plasma. J Pharm Sci. 2004; 93:726.
Best wishes,
Mahesh
Mahesh N. Samtani, Ph.D.
Scientist, Advanced PK-PD Modeling & Simulation
Clinical Pharmacology and Experimental Medicine
Johnson & Johnson Pharmaceutical R&D
PRD 2723, Raritan, NJ 08869
PH # (908) 704-5367
Email: msamtani.aaa.prdus.jnj.com
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As Goncalo mentioned in his e-mail, I have not noticed any
significant difference in LC-MS/MS assay performance between heparin
and EDTA (of all salts) as the anticoagulant in plasma samples
analyses either. One of the considerations for selecting
anticoagulant is that EDTA is a chelating agent, it may interfere
with ELISA assay if metal ions (like Ca ion) are needed as a cofactor
for the enzyme/antibody used in the assay. That's the reason why we
always use heparin for ELISA assay as a precautionary step when we
apply ELISA assays for plasma samples.
Ta Kung Chen, Ph.D.
Associate Director, Bioanalytical Chemistry
Pre-Clinical Development
Neurocrine Biosciences, Inc.
12790 El Carmino Real
San Diego, CA. USA
858 509-1114
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The following message was posted to: PharmPK
While EDTA chelates Ca, heparin activates AT.
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The following message was posted to: PharmPK
Hi there.
The selection of appropriate anticoagulant depends on what you are
interested in. For example, if
electrolite composition of blood is of considerable interest for you
for some reason (enzyme
activation/inactivation) then you should avoid EDTA or fluoride
anticoagulants. In such
circumstances Li heparinate is better choice. Li heparinate is also
only anticoagulant used for
analyses of blood gases. If you are interested in concentration of
coagulation factors than you
should use citrate. It is also a good choice for preservation of
platelets and avoidance of
pseudothrombocytopenia. If you wish to block glycolitic processes
then you should use fluoride. On
the contrary if you wish to preserve red cells then you should choose
dextrose citrate. It should be
kept in mind that citrates are used as solutions and final blood
volume should be recalculated
keeping in mind dilution due to usage of such anticoagulation solution.
In short, if you do not have any special needs EDTA is the simplest
and cheapest anticoagulant. If
you are not certain which anticoagulant to use start with Li
heparinate. Hope this helps.
Zeljko Debeljak, PhD student
Osijek Clinical Hospital
CROATIA
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