(An) example(s) of (a) opioid "prodrug":

Oxycodone is metabolized into a more efficacious analgesic, oxymorphone.

Metabolism of coding, hydrocodone, and oxycodone are metabolized into more effective agents by the CYP2D6 cytochrome P450 isoform.

Analgesic properties of oxymorphone and fentanyl depend on metabolic activation to more active species.

Which one(s) of the following agents inhibit CYP2D6 and as a result may reduce effectiveness of some opioid analgesics which require CYP2D6 for activation.

This opioid route of administration tends to be especially useful in managing in-hospital pain associated with surgery and during end-of-life pain relief.

Administration of nonsteroidal anti-inflammatory drugs may induce pain relief comparable to that provided by about 60 mg codeine.

Morphine administration is helpful in reducing dyspnea associated with low cardiac output and pulmonary edema.

Generally, opioid administration is contraindicated in patients with pulmonary edema provided the patient is not also in severe pain.

Which one(s) of the following may be used as primary anesthetic agent(s) in some surgical cases?