Ask the Doctors

Dear Doctor: When a medication says "take with food," what exactly does that mean? If you take it with a few crackers, does that count? I have a medication I take before going to bed, when I don't feel like eating anything big!

Dear Reader: When it comes to medications, how and when you take them can play a significant role on how effective they are. It also affects how they interact with your body. The direction to "take with food" means that you should not ingest that particular medication on an empty stomach.

There are multiple reasons for this. One is that the components of some medications can cause stomach upset, such as nausea or vomiting, if they are not taken along with food. Additionally, the presence of food can help to buffer the stomach and prevent potential irritation. Over the long term, medications like aspirin and other NSAIDs, corticosteroids like prednisone, as well as some oral contraceptives can cause inflammation or even ulcers when taken on an empty stomach.

The other thing that the presence of food does is to initiate digestion. When you eat, gastric acid is released into the stomach, which helps break down food -- and any medication -- into smaller components. For some medications, the bile and stomach acid produced during digestion boost the rate at which they break down and are absorbed. Conversely, other medications would be absorbed too quickly if taken on an empty stomach. The presence of food helps slow that process.

As to what "with food" actually means, it's not necessarily a full meal. If you happen to be timing your medication to breakfast, lunch and dinner, that's fine. But a few crackers at bedtime, as you said, can be adequate. Ditto for a piece of fruit or a glass of milk. It's probably a good idea to ask your pharmacist why your medication should be accompanied by food. That way, if it's to prevent inflammation or indigestion, you can monitor your response and increase or change the kind of food you're eating to maintain maximum comfort.

But -- and it's a very important one -- not all foods are created equal when it comes to medications. Grapefruit juice and some other fruit juices can change how drugs behave. They can increase the absorption rate of some drugs, including some statins. They can also change how the body metabolizes certain drugs, including antihistamines, birth control pills and blood pressure medications, among others. That means you can wind up with blood levels of a medication that are lower or higher than are optimal. Be sure to read the medication label. If you're uncertain what foods are OK, check with your pharmacist.

What about medications that require an empty stomach?

For these, take them either no less than one hour before a meal, or at least two hours after a meal. And if you're taking them after a meal, that means your medication will do its best work if you don't eat again for another two hours.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

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