Meperidine is primarily eliminated by the kidneys and its elimination is pH dependent. Which detail is correct?

Meperidine is primarily eliminated by the kidneys and its elimination is pH dependent. Which detail is correct?

• A. Excreted Primarily in Urine with pH-Dependent Elimination
• B. Excreted Primarily in Feces
• C. Elimination Independent of Urine pH
• D. Primarily Hepatic Metabolism with Minimal Renal Involvement

Answer: (A)

Meperidine is eliminated mainly by the kidneys, and its renal excretion is influenced by urine pH because it is a weak base. In acidic urine, the drug becomes more ionized and is less readily reabsorbed, leading to increased renal clearance. In alkaline urine, it remains more unionized and is reabsorbed more, reducing clearance. This is why the correct statement is that it is excreted primarily in urine with pH-dependent elimination. While it does undergo hepatic metabolism to normeperidine, the dominant route of elimination is renal, and the pH effect pertains to how urine acidity or alkalinity alters urinary excretion.

Meperidine is eliminated mainly by the kidneys, and its renal excretion is influenced by urine pH because it is a weak base. In acidic urine, the drug becomes more ionized and is less readily reabsorbed, leading to increased renal clearance. In alkaline urine, it remains more unionized and is reabsorbed more, reducing clearance. This is why the correct statement is that it is excreted primarily in urine with pH-dependent elimination. While it does undergo hepatic metabolism to normeperidine, the dominant route of elimination is renal, and the pH effect pertains to how urine acidity or alkalinity alters urinary excretion.