In working with older adults, we know that medication management is an important part of their story. Nearly all of our patients and clients take medications to maintain their health - and most take several medications at different times during the day. 

All of us have heard stories about negative food/drug interactions, but few of us consider ourselves experts in this area. So we asked Paige Katzenstein, one of CHA's outstanding registered dieticians, to help us understand how foods and drugs interact and share information about some common problems.  

When foods and drugs collide 

Paige Katzenstein, RDLDN, CDE

Dietician

Drug-food interactions occur in several ways. Sometimes food can affect the body's absorption of a drug or affect how we metabolize the medication. Certain foods interfere with this process, resulting in too much or too little medicine being released to the body. So if the medication is too low, it may not treat the health condition adequately. If it is too high, it can produce unintended side effects.

Eating certain foods at the same time as your medications may alter the way the meds work. Severe consequences such as kidney failure, respiratory failure, gastrointestinal bleeding, or death can result.   

Who is at greatest risk?

It is more common for the elderly to be at increased risk. But people at any age with a compromised immune system also have higher risk. Also, there might be some specific behaviors or foods people eat that put them at higher risk. 

Common Interactions 

• Statins and Grapefruit. Statins are highly effective cholesterol-lowering drugs. Drinking grapefruit juice or eating fresh grapefruit may increase the amount of some statins in your blood and lead to potentially greater side effects of these drugs. This interaction is especially strong with simvastatin (Zocor) and lovastatin (Altoprev), milder with atorvastatin (Lipitor), and nonexistent for pravastatin (Pravachol). 

• Acetaminophen and Alcohol. The over-the-counter pain reliever acetaminophen (Tylenol) and alcohol don't mix. Two or more alcoholic drinks per day can increase liver toxicity of Tylenol.  This interaction can be especially problematic in older adults since the liver's ability to diminish drugs decreases with age.

• Antibiotics and dairy products. Dairy products such as milk, yogurt, and cheese can delay or prevent the absorption of antibiotics such as tetracyclines and ciprofloxacin (Cipro). To avoid problems, it is recommended to take antibiotics one hour before or two hours after a meal.

• Insulin and Alcohol. An alcoholic drink can increase or prolong the effects of insulin and lead to hypoglycemia and low blood sugar. Symptoms of hypoglycemia include nervousness, sweating, intense hunger, weakness, drowsiness, and ultimately coma.

• Warfarin and Vitamin K. Warfarin (Coumadin) is a blood-thinner that helps treat and prevent blood clots. Eating foods rich in vitamin K can diminish warfarin's effectiveness. Some of the foods with the highest vitamin K content are green leafy vegetables like kale, spinach, collard greens, green cabbage, some other vegetables like broccoli and Brussels sprouts, and chili powder.

• Chocolate and Ambien. If taking Ambien for sleep, chocolate may decrease its effects.

• Vitamin E and Coumadin. The combination can cause excess bleeding. Some foods high in vitamin E are sunflower seeds, almonds, hazelnuts, peanut butter, and certain oils like sunflower oils or safflower oil. 

It's not easy to always figure out what foods can be eaten while taking certain medications, or the timing. So always make sure to check with a doctor, pharmacist, and/or a registered dietician in order to determine which foods to avoid.

All CHA patients have access to the registered dietitian team for nutrition consult services at many CHA primary care sites.

Learn more about food and meds with Paige Katzenstein on my Health is Wealth TV show.