What action is expected when a patient on promethazine develops liver dysfunction?

When a patient on promethazine develops liver dysfunction, switching to a different antiemetic is the appropriate action. Promethazine is metabolized in the liver, and liver dysfunction can significantly affect its metabolism and clearance from the body. As a result, the risk of accumulation and toxicity increases in patients with compromised liver function.

Choosing an alternative antiemetic that is either less hepatically metabolized or has a more favorable safety profile in the context of liver disease is crucial. This switch helps ensure that the patient continues to receive effective antiemetic therapy while minimizing the risk of adverse reactions due to altered drug metabolism.

Other actions, like increasing the dosage or continuing with the current dosage, could lead to potentially dangerous levels of the drug in the system. Administering additional liver support medications does not address the underlying issue of drug metabolism and could complicate management further. Thus, switching to a different antiemetic is the most prudent and safe choice in this scenario.