Bortezomib consumption assessment according to the pharmaceutical form and the sampling device used during reconstitution.
Bortezomib is presented as a lyophyllisate (VELCADE®) or as a ready-to-use solution (RUS) (Bortezomib EG®). Each vial contains 3.5mg of bortezomib in only 1.4ml of solvant. Such a small volume of solution can lead to a waste of product during preparation, resulting in a significant rate of loss. The objective of this study was to assess the loss of Bortezomib 3.5mg/1.4ml RUS depending of the type of collection device used (spikes or needles).
Materials and Methods
A prospective comparative before/after study evaluating two modes of handling was carried out : use of spikes (CH-72® ; ICU medical) during period A and use of 40mm 19G needles during period B.
The primary endpoint was the rate of loss of Bortezomib for each period defined as the number of milligrams prescribed over the number of milligrams consumed. The quantities of known losses have been taken into account (expired remnants, broken vials...). The secondary endpoint was the estimation of additional costs related to losses.
Period A lasted 6 weeks with 230 preparations for 450.73 mg prescribed. The average dose was 1.96 mg (95% CI [1.91-2.01]). The quantity actually consumed was 156 vials (ie 546 mg). The rate of loss was 17.45 % (95.27 mg). Period B lasted 3 weeks with 110 preparations ford 209.38 mg prescribed. The average dose was 1.90 mg (95% CI [1.82-1.99]). The quantity actually consumed was 73 vials (ie 255.5 mg). The rate of loss was 18.05% (46.12 mg).
After extrapolation of these data, the annual additional cost was about 39,000 euros for spikes and 41,000 euros for needles.
This study showed that the rate of loss with spikes was lower than with needles on the contrary of the pharmacy technicians’ perception. These results are similar to those of Charra et al. (SFPO Congress 2017), whose methodology was comparable and which dealed with consumption of VELCADE® (loss of 10.70% for spikes and 12.86% for needles). This difference could be explained by handling techniques : the dead volume within the needles is usually lost which is not the case with spikes. Differences in rate of loss between RUS and lyophilisate could be partly explained by different viscosity or cap shape. This work raises the issue of the quantities actually usable in the vials versus the quantities invoiced by the laboratories.
This study illustrates the differences of effectiveness between several types of sampling devices and the loss of drugs incurred with low volume vials.