Answer
Keep them refrigerated in the original package, protected from light, and never freeze them. Follow the product leaflet's limits if a pen is kept at room temperature.
Sources for this answer
- Adtralza 300 mg solution for injection in pre filled pen — Current selected SmPCemc · Summary of Product Characteristics
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.