Various embodiments of needle assemblies for use with a drug delivery device to deliver two or more medicaments are provided. Additionally, various embodiments of methods for delivering two or medicaments are provided. In one embodiment, a needle assembly comprises an injection needle, a proximal housing member, a distal housing member, and a medicament transfer element. The proximal housing member contains a first medicament and is configured to attach to a drug delivery device containing a second medicament. The distal housing member is movably engaged with the proximal housing member such that relative axial movement between the proximal and distal housing members causes the first medicament to be delivered. Upon activation of the drug delivery device (e.g., activation of a dose button of the drug delivery device) the second medicament is transferred, via the medicament transfer feature, from the drug delivery device to the injection needle of the needle assembly such that the second medicament can be delivered.
