Final answer:
Some opioids that should not be used in renal failure include morphine, oxycodone, and methadone due to their potential toxic metabolites. These drugs can accumulate in the body and cause further kidney damage.
Step-by-step explanation:
Opioids that should not be used in renal failure include morphine, oxycodone, and methadone. These drugs can accumulate in the body and their metabolites can be toxic to the kidneys. For example, morphine is converted into morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G), which can cause renal impairment. Methadone and its metabolites can also accumulate in renal failure and lead to increased toxicity.