Clinical evaluation of pain during subcutaneous injections of low molecular weight heparins in healthy volunteers.

In order to compare the intensity and the duration of the pain following the subcutaneous injection of low molecular weight heparins, 0.4 ml nadroparin, 0.4 ml enoxaparin and 0.4 ml placebo (NaCl 0.9%) were administered at 1 week intervals to 12 healthy volunteers in a randomised, double-blind, three-period study. Pain was assessed by visual analogue and verbal category scales. Based on visual analogue scale scores, nadroparin resulted in significantly less pain than enoxaprin at 1 and 5 min after injection (6.2 +/- 2.6 mm vs 21.9 +/- 5.9 mm; P < 0.05 and 3.5 + 1.5 mm vs 14.3 +/- 4 mm; P < 0.05, respectively, mean +/- s.e. mean). Similar results were obtained using verbal category scale. Confidence interval testing for difference between groups showed that nadroparin injection resulted in less pain than enoxaparin at 1 min (-15.8: -31.2 to -0.4 mm).