This situation primarily exemplifies the principle of nonmaleficence, which is the ethical obligation to not inflict harm intentionally. By uncovering evidence that the medication could be very harmful to the patient and taking action to remove him from it, you are acting to prevent further harm, which aligns with the principle of nonmaleficence.
In contrast:
- Maleficence refers to the intention to do harm, which is not applicable in this case.
- Autonomy relates to respecting the patient's right to make informed decisions about their care, which may also be relevant if you communicated risks effectively.
- Justice involves fairness in treatment and distribution of resources, which is not the primary focus of this scenario.
So, the best answer is 1) nonmaleficence.