How does codeine usually impact GI function?

How does codeine usually impact GI function?

• A. Codeine usually causes diarrhea.
• B. Codeine usually causes constipation.
• C. Codeine has no effect on GI function.
• D. Codeine always induces vomiting.

Answer: (B)

Codeine slows the gut. It is a mu-opioid receptor agonist in the gastrointestinal tract, and this activation reduces smooth muscle contractions (slows peristalsis) and increases water absorption from the stool. The net effect is harder, less frequent stools—constipation. This is the most common and expected GI effect of codeine, especially with regular or higher dosing. Diarrhea would require increased gut motility, which opioids do not typically cause. Vomiting can occur with opioids but is not universal. So constipation is the best-supported GI outcome with codeine. In practice, how you manage this may include ensuring adequate hydration and using stool softeners or laxatives as needed, while considering dose adjustments if constipation becomes troublesome.

Codeine slows the gut. It is a mu-opioid receptor agonist in the gastrointestinal tract, and this activation reduces smooth muscle contractions (slows peristalsis) and increases water absorption from the stool. The net effect is harder, less frequent stools—constipation. This is the most common and expected GI effect of codeine, especially with regular or higher dosing.

Diarrhea would require increased gut motility, which opioids do not typically cause. Vomiting can occur with opioids but is not universal. So constipation is the best-supported GI outcome with codeine. In practice, how you manage this may include ensuring adequate hydration and using stool softeners or laxatives as needed, while considering dose adjustments if constipation becomes troublesome.