Study of Patisiran reconstitution practices: Enforcement of the Summary of Product Characteristics (SPC) in professionals practices

Context
On 08/27/2018 Patisiran got market access authorization for the treatment of hereditary transthyretin amyloidosis. This is the first small interfering double-stranded RNA drug. Thereby, Patisiran need to be reconstituted with specific steps, which are a 0.45μm filtration and a dilution for a total volume of 200mL. As a result, we can wonder if the product has to be reconstitute in the preparatory of the hospital or in clinical unit by nurses. Arguments, whether pharmaco-technicals, economics or practical are debated.

Aim
Compare professional reconstitution practices with the SPC.

Material and Method
Establishment of a multicenter retrospective study. A questionnaire about Patisiran professional reconstituion practices was submitted to 19 hospitals which dispensing it. It deals with arguments of the choice of reconstitution place and its modalities.

Results
16 centers out of 19 have answered. In 5, the reconstitution is realized in clinical units ; 3 of them have trained nurses on this act and have joined a procedure of reconstitution with vials. Arguments in favor of this choice were the lack of activity in the compounding pharmacies, the absence of place dedicated to non-cytotoxic drugs preparation/reconstitution (therefore a risk of cross contamination) and the distance between compounding pharmacies and the clinical unit. The 11 pharmacies who have chosen to reconstitute the Patisiran in the hospital compounding pharmacies have reported as arguments : the reconstitution’s complexity (n=10), the dispensation’s security of this kind of medicine (n=3) and the cost of the product (n=2).
About filtration, 63% (n=10) do it with a face-to-face syringes montage, 25% (n=4) in a container like a beaker, 6% (n=1) in a sterile crimped vial, 6% (n=1) directly during the injection in the infusion bag. The dilution is done in 69% (n=11) of case in commercials 250ml bag adjusted to 200mL, in 25% (n=4) of cases in empty infusion bag filled to 200ml final volume with solvent and finally in 6% (n=1) of cases in empty infusion bag filled with fix volume of 180ml of solvent.

Discussion
Because of the complexity of the reconstitution the majority of hospitals have opted to reconstitute the Patisiran in the hospital compounding pharmacies. However, 2 of them wish to delegate the reconstitution to the nurses in clinical unit after a training period.
In our center, clinical unit nurses reconstitute. They filter when injecting the Patisiran in the infusion bag with 0.45μm filter beforehand moisten. Thanks to that the retention volume is decreased from 1mL to 0.1ml, allowing to limit the losses. We don’t respect the dilution in 200mL as it written in the SCP because it’s due to American practice and the fact that they have commercial 200mL infusion bags but no to pharmacological and stabilities arguments.

See te poster