What must be included in a prescription for controlled substances?

In the context of prescriptions for controlled substances, including the prescriber's DEA number is essential for regulatory compliance and patient safety. The Drug Enforcement Administration (DEA) requires that every prescription for a controlled substance must contain the prescriber’s DEA registration number to verify that the prescriber is authorized to write prescriptions for these medications. This helps to prevent the misuse and diversion of controlled substances by ensuring that only qualified healthcare providers can legally prescribe them.

The prescriber's DEA number serves as a unique identifier that links the prescription to a legitimate medical practice, providing an important safeguard against illegal prescribing practices. Without this number, a pharmacy would be unable to process the prescription legally, which could lead to non-compliance with applicable laws and regulations.

Each of the other options lacks critical information that is mandated for the validity of controlled substance prescriptions. Therefore, including the prescriber's DEA number is crucial for both legal and safety reasons in the prescription process.