Which entity must be informed about significant adverse drug reactions (ADRs)?

When it comes to significant adverse drug reactions (ADRs), the primary care physician of the patient is the key entity that must be informed. This is because the primary care physician oversees the patient's overall health care and is responsible for making medical decisions based on all aspects of the patient's health, including medications. By being aware of any significant ADRs, the physician can evaluate the patient's condition, consider alternative treatments, and take necessary actions to prevent further complications or harm.

While the pharmacist's supervisor and the local pharmacy board may need to be informed about ADRs in certain contexts, such as for regulatory or internal review purposes, these parties are not directly involved in the immediate health care of the patient. Adult Protective Services typically address concerns related to abuse or neglect and would not be the appropriate agency for reporting ADRs related to medication use. Therefore, the primary care physician is the most critical contact to ensure the patient's safety and continuity of care in the event of significant ADRs.