Pharmacies should assign a lot number to any medication that has been:

Reconstitution involves mixing a medication with a diluent to prepare it for administration, but it does not constitute a batch production process requiring a lot number. Typically, reconstituted medications are individual preparations, and while they may be labeled for use, they do not necessitate a lot number as they are not produced in bulk.

A recalled medication refers to items withdrawn from the market due to safety concerns or defects, and while tracking may be necessary, the assignment of a lot number is not applicable in this context. Lot numbers are assigned during production, not retrospectively after a recall has been issued.

A medication being contraindicated implies it should not be used for specific patients due to potential harm; however, this status does not require a lot number. The assignment of lot numbers relates to production and tracking of medications, not their individual suitability for patients.