If solid content in the large intestine increases, shifting the ct curve, this would cause the curve to:

• A. Shift upward
• B. Shift to the left
• C. No change
• D. Shift downward

Answer: (D)

Concentrations in the blood after a dose reflect how much drug is absorbed and how fast it appears in systemic circulation. If the large intestine has more solid content, dissolution of the drug into the lumen slows and the amount that can be absorbed decreases. With less drug entering the bloodstream at each time point, the entire concentration–time profile becomes lower, so the curve shifts downward. This aligns with reduced systemic exposure.

A leftward shift would mean the drug peaks sooner (faster absorption), which isn’t what increasing solid content does. An upward shift would imply higher concentrations, which would require more absorption, not less. No change would mean absorption isn’t affected, which isn’t the case here.