Under which condition is a pharmacist not required to substitute a generic medication?

A pharmacist is not required to substitute a generic medication when a physician prescribes a branded drug. In such cases, the prescription specifically indicates that the brand-name medication is needed, and the pharmacist must adhere to the prescriber's intent. This ensures that the patient receives the exact medication the physician intended, which can be crucial for efficacy, safety, or particular patient considerations.

While other scenarios may involve the possibility of substitution, they do not apply in the context of a physician prescribing a brand-name medication. For example, patient requests for brand-name drugs do not override the prescriber's directive. Additionally, generic alternatives being available does not obligate a pharmacist to substitute if the prescription indicates a brand-name drug, whether the pharmacist offers to dispense at a generic price or not.