Dosage of enoxaparin among obese and renal impairment patients.
BACKGROUND
Enoxaparin dosage for obese patients and patients with renal impairment remains controversial.


OBJECTIVE
To compare anti-factor Xa activity (anti-Xa) among obese and renal impairment patients to patients with healthy weight and adequate renal function.


METHODS
Open, prospective, nonrandomized clinical trial.


METHODS
A major community teaching hospital.


METHODS
A total of 233 patients with prescription of enoxaparin.


METHODS
Enoxaparin 1.5 mg/kg once daily or 1 mg/kg twice daily except those on dialysis, who received 75% of the dose.


METHODS
Anti-Xa was measured 4 h post-injection on day 2 or 3.


RESULTS
Mean (95% confidence interval (95% CI)) anti-Xa was equal to 1.14 IU/mL (1.07-1.21) and 1.14 IU/mL (1.08-1.20) among patients who received one (n=92) and two injections (n=122) per day, respectively. Anti-Xa increases with body mass index (BMI) (0.01 IU/mL for each kg/m2; 95% CI: 0.002-0.017), but the increase is insufficient to reach supratherapeutic anti-Xa. Anti-Xa decreases with higher creatinine clearance (CrCl) (-0.003 IU/mL for each mL/min; 95% CI: -0.006 to -0.001). On the twice-daily regimen, this is sufficient to reach supratherapeutic anti-Xa. The odd ratio (OR) (95% CI) of having a nontherapeutic anti-Xa is equal to 2.28 (1.25-4.16) when enoxaparin is administered twice daily and to 3.03 (1.16-7.86) among severe renal impairment patients (< or =30 mL/min).


CONCLUSIONS
Based on Anti-Xa, no dosage adjustments are required in obese patients. In renally impaired patients, adjustments may be necessary when enoxaparin is administered twice daily.
Bazinet
Annie
A
Cité de la Santé de Laval, Quebec, Canada.
Almanric
Karine
K
Brunet
Catherine
C
Turcotte
Isabel
I
Martineau
Josée
J
Caron
Stéphanie
S
Blais
Normand
N
Lalonde
Lyne
L
D000368:Aged; D001780:Blood Coagulation Tests; D001835:Body Weight; D002318:Cardiovascular Diseases / Q000188:drug therapy; D016903:Drug Monitoring; D017984:Enoxaparin / Q000008:administration & dosage* / Q000493:pharmacokinetics; D065427:Factor Xa Inhibitors; D005260:Female; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity; D051437:Renal Insufficiency
D017984:Enoxaparin; D065427:Factor Xa Inhibitors; D006495:Heparin, Low-Molecular-Weight