Which of the following actions can a PCA take concerning drug administration?

The appropriate action a PCA can take concerning drug administration is to record and report the patient's reaction to medication. This is important because monitoring and documenting how a patient responds to medication helps ensure their safety and the effectiveness of their treatment. It enables healthcare professionals to adjust care plans as needed and to identify any side effects or adverse reactions that may require further intervention.

While PCAs play an important role in patient care, they are not typically authorized to administer medication, change dosages, or suggest alternative medications. These responsibilities are generally reserved for licensed healthcare professionals such as nurses or doctors, who have the training and authority to make such decisions regarding medication management. Thus, the correct choice emphasizes the PCA's responsibility in monitoring and communication rather than in direct medication management.