When one drug changes how another drug works.

• A. Gastrointestinal
• B. Pancreatitis
• C. Drug interaction
• D. Hypoglycemia

Answer: (C)

One drug changing how another works is a drug interaction. This captures the idea that medicines can affect each other’s activity, either by altering how much of a drug is in the body (pharmacokinetic) or by changing how a drug acts at its target (pharmacodynamic). Recognizing drug interactions helps anticipate higher or lower drug levels, increased side effects, or reduced efficacy. The other terms refer to specific medical problems or areas: gastrointestinal relates to the digestive tract, pancreatitis is inflammation of the pancreas, and hypoglycemia is low blood sugar. None describe the interaction between two drugs, so the correct concept is drug interaction.