Meperidine metabolism involves what pattern?

Meperidine metabolism involves what pattern?

• A. It is not metabolized and excreted unchanged
• B. It undergoes extensive hepatic metabolism, with 90% converted to normeperidine (active) and meperidinic acid; active metabolite can accumulate in renal dysfunction.
• C. It is exclusively renally excreted
• D. It is converted to morphine in the liver

Answer: (B)

Meperidine is mainly processed by the liver, undergoing N-demethylation to an active metabolite called normeperidine, with another pathway producing meperidinic acid. The metabolites are then cleared by the kidneys. Because normeperidine can accumulate when renal function is impaired, this can lead to CNS toxicity such as agitation, tremors, and seizures, especially in the elderly or those with kidney dysfunction. Meperidine itself is not excreted unchanged in large amounts, and it is not converted to morphine in the liver.

Meperidine is mainly processed by the liver, undergoing N-demethylation to an active metabolite called normeperidine, with another pathway producing meperidinic acid. The metabolites are then cleared by the kidneys. Because normeperidine can accumulate when renal function is impaired, this can lead to CNS toxicity such as agitation, tremors, and seizures, especially in the elderly or those with kidney dysfunction. Meperidine itself is not excreted unchanged in large amounts, and it is not converted to morphine in the liver.