Some Foods and Medications Just Don't Mix

Food and Drug Interactions

A spoonful of sugar may help the medicine go down, but there are some foods that can make drugs less effective and even more harmful.

“Interactions between foods, including beverages, can have a profound impact on the potential side effects of drugs as well as the success of the actual drug itself,” says Donna White, RPh, CDE, a clinical pharmacy coordinator for Ambulatory Care at University of Virginia Health System.

Empty or Full?

Drug labels may advise taking a medication on either a full or empty stomach. This is because food or beverage intake can alter drug absorption, or the process in which drugs enter the blood stream.

Occasionally even the content of a meal can have an impact. “If the meal is higher in fat content, then the medication may be absorbed more fully and quickly,” said White. “Some drugs are not as stable in an acidic stomach environment and may not be as effective. Also, some components of food like calcium found in dairy products may actually bind to the drug making it less effective.” 

Avoid Risky Combinations

Certain food and drug mixtures can be extremely harmful or even life-threatening. Some of the more common include:

• Grapefruit and Statin Drugs
  You may have heard of the dangers of combining grapefruit or grapefruit juice with cholesterol medications or statin drugs (i.e., Lipitor®, Mevacor®, Zocor®). Grapefruit contains an ingredient that blocks the breakdown of statin drugs making them more potent, which may increase the risks of muscle pain or inflammation, according to White.
  

• MAOIs and High-Tyramine Foods
  Monoamine oxidase inhibitors are used to treat depression but can cause blood pressure to skyrocket when mixed with foods containing high tyramine levels. These include aged cheeses, or pickled foods and beverages and, to a lesser extent, chocolates and yeast-containing foods. MAOIs prevent the breakdown of tyramine in the body, which can lead to a potential blood pressure crisis, heart arrhythmia or brain hemorrhage.

• Warfarin and Vitamin K-Rich Vegetables
  The blood thinner Warfarin is made less effective when combined with vegetables high in vitamin K, which include dark leafy greens such as brussel sprouts and spinach.

• Vitamins or Antacids and Antibiotics
  Vitamins or antacids may contain minerals such as calcium, iron or magnesium that can decrease the efficacy of certain antibiotics. For example, the antibiotic ciprofloxacin becomes less effective if given with antacids because the medication binds to magnesium and calcium. 

•  Alcohol & Almost Any Medicine
  The potential for harmful alcohol and drug interactions is great with a variety of medications. “Over the counter (OTC) antihistamines, pain medicines, medicines to prevent dizziness or nausea, sleep aids and any sedative drug will have potentiated sedation with the consumption of alcohol,” said White. “Some drugs may cause vomiting, dizziness, flushing and a very fast heart rate if taken with alcohol. The antibiotic metronidazole is an example of this.”

Check with a Pharmacist

Most medicines are not affected by nutritional intake but, according to White, it’s best to ask your pharmacist and educate yourself on potential food and drug interactions. White offers the following tips:

• Read the label for all OTC and prescription medications

• Ask your pharmacist or doctor how to take your medicine

• Take medicine with a full glass of water, unless your physician directs otherwise

• One hour prior to eating or two hours after a meal qualifies as an “empty” stomach

• Don't take vitamins at the same time as your other medicines unless you are told it is ok

• Read all the directions, interactions and warnings printed on the drug label and package information

• Avoid adding medication to food or crushing it unless your provider tells you to do so

• Do not take medication with alcohol

• Avoid mixing medication in hot drinks

• Remember, if you have any questions, ask your pharmacist!