Opioids are excreted primarily by which route?

• A. Via lungs
• B. Renally
• C. Hepatically
• D. Biliary

Answer: (B)

The main idea here is how opioids leave the body. For most opioids, the primary route of excretion is through the kidneys. After the liver metabolizes opioids, they are often converted into water-soluble glucuronide conjugates (such as morphine-3-glucuronide and morphine-6-glucuronide) that are filtered by the kidneys and eliminated in urine. Because these metabolites are cleared renally, urinary excretion is the dominant exit path.

Exhalation through the lungs is not a major route for opioids, and while some drugs may have biliary excretion, that pathway does not account for the majority of elimination for typical opioids. Metabolism in the liver is important for preparing the drug for excretion, but the route of elimination is primarily renal.