Which opioid has a toxic metabolite that may cause seizures?

Which opioid has a toxic metabolite that may cause seizures?

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

Answer: (C)

Meperidine has a toxic metabolite called normeperidine that can accumulate, especially in people with kidney impairment or after high-dose, prolonged use. Normeperidine is a CNS stimulant and can lower the seizure threshold, leading to tremors, myoclonus, and seizures. This risk makes meperidine unique among common opioids, which is why it’s avoided in patients at risk for seizures or with renal dysfunction. Other opioids like morphine, fentanyl, and hydromorphone do not have a toxic metabolite that is known to provoke seizures in routine practice, so they are preferred when seizure risk is a concern.

Meperidine has a toxic metabolite called normeperidine that can accumulate, especially in people with kidney impairment or after high-dose, prolonged use. Normeperidine is a CNS stimulant and can lower the seizure threshold, leading to tremors, myoclonus, and seizures. This risk makes meperidine unique among common opioids, which is why it’s avoided in patients at risk for seizures or with renal dysfunction. Other opioids like morphine, fentanyl, and hydromorphone do not have a toxic metabolite that is known to provoke seizures in routine practice, so they are preferred when seizure risk is a concern.