In regard to calcium carbonate use with aspirin, what is a potential negative outcome for Charlie?

The potential negative outcome for Charlie regarding the use of calcium carbonate with aspirin relates to the reduced effectiveness of aspirin. Calcium carbonate is an antacid that can alter the gastric pH. When the pH of the stomach is increased, it can affect the solubility and absorption of certain medications, including aspirin, which is designed to be absorbed in the acidic environment of the stomach.

When aspirin is less effectively absorbed due to changes in gastric pH caused by calcium carbonate, the therapeutic effects of aspirin may be diminished. This can especially have ramifications for individuals who are relying on aspirin for its antiplatelet effects or pain-relieving properties. Therefore, this interaction is clinically significant and highlights the importance of monitoring and understanding drug interactions in pharmacology.