Which opioid is discouraged in older adults due to risk of delirium and neurotoxicity?

• A. Meperidine
• B. Morphine
• C. Hydromorphone
• D. Oxycodone

Answer: (A)

In older adults, the risk of delirium and neurotoxicity from opioids is a major safety concern. Meperidine stands out here because its metabolism produces an active metabolite called normeperidine, which can accumulate, especially when kidney function is reduced—as is common with aging. This buildup can directly irritate the nervous system, leading to agitation, tremors, myoclonus, and seizures, i.e., delirium and neurotoxicity. Because of this, the Beers Criteria discourages using meperidine in older adults, favoring other opioids that don’t produce a clearly neurotoxic metabolite at typical dosing. The other opioids listed can still cause CNS side effects and require careful monitoring, but they don’t carry the same well-established risk of delirium from an accumulating neurotoxic metabolite.