Compared with morphine, meperidine is associated with fewer constipation and biliary spasms. Which option reflects this statement?

Compared with morphine, meperidine is associated with fewer constipation and biliary spasms. Which option reflects this statement?

• A. Less Constipation and Fewer Biliary Spasms
• B. More Constipation than Morphine
• C. No Placental Transfer
• D. Higher Biliary Spasm Risk

Answer: (A)

Opioid choices differ in how they affect gastrointestinal motility and biliary sphincter tone. Morphine tends to slow gut motility (constipation) and causes sphincter of Oddi spasm, which can increase biliary pressure and provoke biliary colic. Meperidine, by contrast, has a weaker effect on these biliary and GI smooth muscles, so it is associated with less constipation and fewer biliary spasms. This makes the statement describing meperidine as having fewer constipation and biliary spasms the best reflection of its comparative adverse effect profile. The other ideas don’t fit the comparison: when considering placental transfer, meperidine does cross the placenta, so “no placental transfer” isn’t correct; and the notion of higher biliary spasm risk or more constipation than morphine contradicts the known differences in how meperidine interacts with biliary and GI smooth muscle.

Opioid choices differ in how they affect gastrointestinal motility and biliary sphincter tone. Morphine tends to slow gut motility (constipation) and causes sphincter of Oddi spasm, which can increase biliary pressure and provoke biliary colic. Meperidine, by contrast, has a weaker effect on these biliary and GI smooth muscles, so it is associated with less constipation and fewer biliary spasms. This makes the statement describing meperidine as having fewer constipation and biliary spasms the best reflection of its comparative adverse effect profile.

The other ideas don’t fit the comparison: when considering placental transfer, meperidine does cross the placenta, so “no placental transfer” isn’t correct; and the notion of higher biliary spasm risk or more constipation than morphine contradicts the known differences in how meperidine interacts with biliary and GI smooth muscle.