Administration with food and other drugs can affect bioavailability. Which statement is true?

• A. It can alter bioavailability
• B. It always increases bioavailability
• C. It never affects bioavailability
• D. It only affects inhaled medications

Answer: (A)

The amount of drug that reaches the bloodstream can change when you take it with food or with other drugs. Food can alter stomach acidity, how quickly the stomach empties, and how well a drug dissolves, so absorption can go up or down depending on the medication. Some drugs are better absorbed with a fatty meal, while others are hindered by food because of complexation or slower gastric emptying. Interactions with other drugs can modify metabolism in the gut or liver, alter transporter activity, or form compounds that reduce absorption. Grapefruit juice, for example, can block intestinal enzymes and raise exposure for certain drugs, while dairy products or antacids can chelate or bind some antibiotics and lower absorption. Because these effects can either increase or decrease bioavailability, the true statement is that it can alter bioavailability. It’s not always increased, it’s not limited to inhaled meds, and it can affect many routes of administration.