Argatroban dosage requirements and outcomes in intensive care versus non-intensive care patients.
OBJECTIVE
To compare the outcomes of reduced-dose argatroban therapy in patients in the intensive care unit (ICU) with those of non-ICU patients.


METHODS
Retrospective medical record review.


METHODS
Large, academic, tertiary care hospital.


METHODS
Thirty-eight ICU patients and 43 non-ICU patients who received the institutional protocol of argatroban 0.8 microg/kg/minute and 1.2 microg/kg/minute, respectively, between March 2004 and September 2005.


RESULTS
Data on patient demographics, argatroban dosing, heparin-induced thrombocytopenia antibody results, activated partial thromboplastin times (aPTTs), new thrombotic events, and major bleeding events were extracted from medical records. Time-weighted mean +/- SD doses of argatroban were 0.82 +/- 0.3 microg/kg/minute for ICU patients and 1.25 +/- 0.29 microg/kg/minute for non-ICU patients. Mean aPTT ratios were similar between groups: 2.07 +/- 0.53 for ICU patients and 2.00 +/- 0.45 for non-ICU patients. More than 70% of all aPTT ratios were therapeutic. More than 95% of patients in both groups achieved a therapeutic aPTT ratio during therapy. Fewer ICU patients than non-ICU patients had all therapeutic aPTT ratios during argatroban therapy (29% vs 51%, p=0.07). Thrombotic events occurred in six (16%) ICU patients versus none of the non-ICU patients (p=0.009). Thrombotic events occurred in 4 (31%) of the 13 ICU patients with confirmed heparin-induced thrombocytopenia. Major bleeding occurred in four (11%) ICU patients versus none of the non-ICU patients (p=0.04).


CONCLUSIONS
Both ICU and non-ICU patients require less than the manufacturer-recommended initial dosage of argatroban. However, ICU patients appear to be at an increased risk for bleeding and thrombotic events despite their attainment of therapeutic aPTTs.
Smythe
Maureen A
MA
Departments of Pharmaceutical Services, William Beaumont Hospital, Royal Oak, Michigan 48073, USA.
Koerber
John M
JM
Forsyth
Lisa L
LL
Priziola
Jennifer L
JL
Balasubramaniam
Mamtha
M
Mattson
Joan C
JC
D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects*; D001120:Arginine / Q000031:analogs & derivatives; D003422:Critical Care / Q000706:statistics & numerical data*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006493:Heparin / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D010314:Partial Thromboplastin Time / Q000379:methods; D010875:Pipecolic Acids / Q000009:adverse effects / Q000627:therapeutic use; D012189:Retrospective Studies; D013449:Sulfonamides; D013921:Thrombocytopenia / Q000139:chemically induced / Q000188:drug therapy*; D013927:Thrombosis / Q000139:chemically induced / Q000188:drug therapy; D016896:Treatment Outcome
D000925:Anticoagulants; D010875:Pipecolic Acids; D013449:Sulfonamides; D006493:Heparin; D001120:Arginine; C031942:argatroban