Final answer:
An oral drug best absorbed in an acidic environment should be administered on an empty stomach to maximize effectiveness. Nutrient absorption primarily occurs in the small intestine, facilitated by enzymes such as bile and pepsin.
Step-by-step explanation:
An oral drug that is best absorbed in an acidic environment should be administered on an empty stomach. This is because the stomach's acidity is highest when it is empty, which can enhance the absorption of medications that require an acidic pH for optimal absorption. Eating food can increase stomach pH and thus might reduce the effectiveness of these medications.
When you eat food, it is vital that the nutrients be absorbed. Absorption occurs primarily in the small intestine, where the majority of digestion also takes place. This process is facilitated by various enzymes and bile. For example, bile is produced by the liver and helps in the digestion and absorption of fats, while pepsin, produced in the stomach, helps digest proteins.