PMID- 20334457
OWN - NLM
STAT- MEDLINE
DCOM- 20100624
LR  - 20100325
IS  - 1875-9114 (Electronic)
IS  - 0277-0008 (Linking)
VI  - 30
IP  - 4
DP  - 2010 Apr
TI  - Unfractionated heparin dose requirements targeting intermediate intensity 
      antifactor Xa concentration during pregnancy.
PG  - 369-74
LID - 10.1592/phco.30.4.369 [doi]
AB  - STUDY OBJECTIVE: To describe unfractionated heparin (UFH) dosing requirements and 
      monitoring parameters to achieve target antifactor Xa concentrations in pregnant 
      women receiving intermediate-dose UFH therapy. DESIGN: Retrospective cohort 
      analysis. SETTING: Centralized anticoagulation service in an integrated health 
      care delivery system. PATIENTS: Twenty-five pregnant women (who had 27 
      pregnancies) who received intermediate-dose UFH between January 1, 1998, and 
      March 31, 2005. MEASUREMENTS AND MAIN RESULTS: Demographic and clinical data were 
      retrieved by using an integrated electronic medical, pharmacy, and laboratory 
      records system. The primary outcome was the required UFH dose at the time of 
      first target antifactor Xa level achieved. Antifactor Xa levels were measured at 
      the mid-dosing interval for UFH. An antifactor Xa assay concentration of 0.1-0.3 
      unit/ml was used as the target range for intermediate-dose UFH for antithrombotic 
      management of pregnant women as described in the American College of Chest 
      Physicians clinical practice guidelines. The mean UFH dose required to achieve 
      this target antifactor Xa range was 236.9 units/kg/day. The UFH doses required to 
      achieve target antifactor Xa levels correlated significantly with patient weight 
      (r = 0.682, p<0.001). The final UFH dose/kg required at the end of pregnancy was 
      similar to that at the first target level (p>0.05) when adjusted for weight. 
      However, the total daily amount of UFH did increase by the end of pregnancy 
      (21,889 vs 19,320 units, p=0.02). There was an average of 7.9 antifactor Xa 
      determinations and 3.1 dosage modifications during the mean of 19 weeks of 
      antenatal UFH therapy. Most (62%) antifactor Xa levels were within the target 
      range. No thromboembolic events, heparin-induced thrombocytopenia, or osteopenic 
      fracture occurred. There was one hemorrhagic complication that resolved with 
      temporary withdrawal of UFH. CONCLUSIONS: Pregnant women required a mean UFH dose 
      of 236.9 units/kg/day to achieve the targeted antifactor Xa level of 0.1-0.3 
      unit/ml. The required UFH doses correlated with patient weight, and most 
      antifactor Xa levels were within the desired target range. These findings may 
      assist clinicians in more precisely initiating and monitoring intermediate-dose 
      UFH in pregnant patients.
FAU - Clark, Nathan P
AU  - Clark NP
AD  - Clinical Pharmacy Anticoagulation Service, Kaiser Permanente Colorado, Lafayette, 
      Colorado, USA. nathan.clark@kp.org
FAU - Delate, Thomas
AU  - Delate T
FAU - Cleary, Steven J
AU  - Cleary SJ
FAU - Witt, Daniel M
AU  - Witt DM
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Pharmacotherapy
JT  - Pharmacotherapy
JID - 8111305
RN  - 0 (Blood Coagulation Factors)
RN  - 9005-49-6 (Heparin)
SB  - IM
MH  - Blood Coagulation Factors/*administration & dosage
MH  - Body Weight
MH  - Clinical Protocols
MH  - Female
MH  - Heparin/*administration & dosage/therapeutic use
MH  - Humans
MH  - Pregnancy
EDAT- 2010/03/26 06:00
MHDA- 2010/06/25 06:00
CRDT- 2010/03/26 06:00
PHST- 2010/03/26 06:00 [entrez]
PHST- 2010/03/26 06:00 [pubmed]
PHST- 2010/06/25 06:00 [medline]
AID - 10.1592/phco.30.4.369 [pii]
AID - 10.1592/phco.30.4.369 [doi]
PST - ppublish
SO  - Pharmacotherapy. 2010 Apr;30(4):369-74. doi: 10.1592/phco.30.4.369.