When a subject in a clinical research trial experiences a serious, unanticipated adverse drug experience, the investigator must take the following steps with respect to the Institutional Review Board (IRB):

• Report the adverse event to the IRB promptly and in a timely manner , following the IRB's specific policies and procedures for reporting adverse drug experiences. This typically involves using designated forms or electronic reporting systems provided by the IRB

• Determine if the adverse event qualifies as an unanticipated problem involving risks to human subjects (i.e., an event that is serious, unexpected, and related to the investigational drug). Such events must be reported to the IRB as they may affect subject safety and the ethical conduct of the trial

• Report serious adverse events (SAEs) to the trial sponsor without undue delay , usually within 24 hours of becoming aware of the event. The sponsor then has regulatory responsibilities to report to authorities and other investigators as required

• Document the adverse event thoroughly in the subject’s medical records and the trial case report forms, including details such as onset date, severity, relatedness to the drug, actions taken, and outcome

• Follow up on the event until resolution or stabilization and provide updates to the IRB and sponsor as necessary

In summary, after discovering a serious, unanticipated adverse drug experience, the investigator must promptly notify the IRB according to its reporting requirements, report the event to the sponsor within 24 hours, and maintain thorough documentation and follow-up of the event to ensure participant safety and regulatory compliance