Drug Interactions: Foods That Can Affect Your Meds

Some foods can affect your prescription meds and cause adverse reactions. Learn about 10 common drug interaction and what to watch out for.

Prescription medications often come with instructions on how to take them with or without food. There may be directions that state not to take on an empty stomach, or to eat one hour before taking or wait at least three hours after a meal. These instructions are given to either increase the amount of the drug in the blood stream, or to lower the drug’s concentration in the blood to aid in delivery and effectiveness. While most people follow these common directives, what happens in the case of drug interactions? Could it be as pertinent to know what foods you should or, more importantly, should not take with your meds?

Food and Drug Interactions That Can Affect Your Health

Here are 10 commonly prescribed meds and the foods they may interact with.

1. Lipitor

Lipitor, or atorvastatin, belongs to the statins, a group of drugs prescribed to treat high cholesterol. They work by reducing the amount of bad (LDL) cholesterol in the blood, or raising the good (HDL) cholesterol, lowering the chance of stroke or heart attack.

Known food and drug interactions: Lipitor is among the most prescribed in the statin group, and foods that are high in fat and cholesterol such as butter, bacon, palm or coconut oil, can reduce its efficacy. Grapefruit juice and grapefruit should be avoided. Excessive consumption (more than a quart a day) can raise the levels of the statins and increase the possibility of side effects, especially muscle pain. You may experience enhanced side effects, such as muscle pain due to an increasing amount of the medication in your bloodstream,

“It’s just like when you do a lot of exercising and produce lactic acid, and it gets deposited in muscles,” says Mary Jackson-Hammond MD, MPH, a Detroit-based family practice physician.
“Sometimes [the pain] goes away, but sometimes it can be long lasting, and that would be a reaction you probably wouldn’t be able to live with. A lot of people like to take them at night when the muscles are at rest.”

2. Xanax

Xanax, or alprazolam, a member of the benzodiazepine family, is used as a sedative in the treatment of anxiety and panic disorders, among other diagnoses.

Some foods can affect your prescription meds and cause adverse reactions. Learn about 10 common drug interaction and what to watch out for.

Photo: Payachi

Known food and drug interactions: Like Lipitor, if you’re on Xanax, you may want to steer clear of grapefruit for breakfast. Grapefruit interferes with the way certain drugs are broken down in the liver and intestines, and can prolong the drug’s effects by causing it to build up in the bloodstream.

If you take Xanax or other benzodiazepines, consider avoiding grapefruit products in your diet or speak with your doctor about changing the Xanax dosage or taking another medication with no effects from grapefruit.

3. Coumadin

Coumadin, or warfarin, is an anti-coagulant that is used to prevent blood clots from forming, to treat hypertension, and to reduce the risk of stroke and heart attack.

Known food and drug interactions: Leafy greens such as kale, spinach and other greens that are rich in vitamin K, can lower the effectiveness of Coumadin to prevent blood clots when ingested in large amounts. As long as you’re eating a balanced diet and not downing huge spinach salads for every meal, you shouldn’t have to worry about having your daily kale smoothie.

Green tea, cranberry juice and cranberry products work against anticoagulants like Coumadin as well. If you’re on blood thinners, consider limiting your ingestion of these foods, as they may lead to bleeding problems.

4. Zestril

Zestril, or lisinopril, is an angiotensin-converting enzyme (ACE) inhibitor that relaxes blood vessels and may be prescribed alone or in conjunction with other medicines to treat high blood pressure. ACE inhibitors work by blocking a substance in the body that tightens the blood vessels, leading to increases in blood pressure.

Known food and drug interactions: Hyperkalemia, too much potassium in your blood, can be exacerbated by Zestril and further complicated by salt substitutes, potassium supplements or foods high in potassium. If you have hyperkalemia and are on Zestril, it is recommended that you lower your intake or eliminate high-potassium containing foods such as bananas, oranges, mangos, cantaloupe, honeydew, peanut butter and broccoli, to name just a few.

5. Albuterol

Albuterol, or albuterol sulfate, is a bronchodilator that relaxes the muscles in the airways, allowing more air to flow into your lungs. It is used to treat wheezing or shortness of breath caused by asthma, bronchitis and other chronic respiratory conditions.

Known food and drug interactions: Often given as an inhalant for people experiencing troubled breathing, Albuterol works by opening the airways, but also increases some side effects, such as nervousness, and elevates the heart rate. The Food and Drug Administration (FDA) recommends limiting any other substances that raise the heart rate, such as caffeine-containing foods and beverages like coffee, coffee beans, certain teas and energy drinks.

“In moderation, these products aren’t particularly bad, but if you are a heavy coffee drinker, for example, it may have a compounding effect if you use the inhaler a lot,” says Jackson-Hammond. “The inhaler is supposed to be used as needed. Many people will use it more often, and that increase in dosing is a sign that your asthma is not being controlled, and that is a good reason to consult your physician.”

6. Motrin and Advil

Ibuprofen is a non-steroidal anti-Inflammatory drug (NSAID) prescribed for inflammation, fever and pain associated with conditions such as osteoarthritis, headaches and general muscle aches and pains.

Known food and drug interactions: NSAIDs can cause stomach bleeding with prolonged use and in the short-term can upset the stomach. NSAIDS are known to do this more when taken alone so do use food or milk to quell their effects if you experience an upset stomach. In this sense, it’s not what food to avoid, but what to reach for.

7. Sumycin

Sumycin, or tetracycline, is an antibiotic used to treat bacterial infections, including pneumonia, and skin infections, such as acne, to stop their spread and control the growth of the bacteria.

Some foods can affect your prescription meds and cause adverse reactions. Learn about 10 common drug interaction and what to watch out for.

Photo: Alex Jones

Known food and drug interactions: Antibiotics such as tetracycline are to be taken with water only and on an empty stomach. For antibiotics to work, they have to be absorbed in the gut. Users are warned against taking them with dairy products, as the calcium in these products can block absorption of the drug, making it less effective. It’s best to take a few hours before or after eating any meals, especially those containing dairy.

8. Synthroid

Synthroid, or levothyroxine, is a synthetic hormone used in the treatment of hypothyroidism, a condition caused when the thyroid gland does not make enough thyroxine, a naturally occurring hormone that regulates your body’s metabolic system. Synthroid mimics the body’s natural hormone production in the thyroid gland — a process known as “thyroid replacement therapy” — to help speed up your metabolic rate.

Known food and drug interactions: Avoid soy, walnuts and other high fiber foods, which can prevent absorption when taking thyroid drugs like Synthroid. Iodine-rich foods, such as seafood and seaweed, can make your prescription ineffective or require higher dosage.

9. Humalog

Humalog, or insulin lispro, is a rapid-acting insulin analog, synthesized to mimic human insulin. Insulin, a naturally-occurring human hormone, regulates blood sugar and is used to control blood glucose when the body does not produce enough, as is the case in people with diabetes.

Known food and drug interactions: With insulin injections, it becomes important to count your carbs to have enough insulin to metabolize them. Diets that avoid taking in animal products and refined carbs such as white breads, sugary sodas and sweets are best when taking insulin. Low-fat and high fiber foods are recommended to assist in the delivery of the drug.

10. Flagyl

Flagyl, also known as metronidazole, is an antibiotic used to treat a wide variety of bacterial infections, commonly prescribed for complications due to Crohn’s disease.

Known food and drug interactions: With this kind of antibiotic, people are warned to avoid aged, pickled, and fermented foods like cheese, and sausages, which contain tyramine, an amino acid that could spike your blood pressure. Bananas, chocolate and avocados are also to be avoided. Most importantly for takers of Flagyl is a strict “no alcoholic beverages” policy, according to Jackson-Hammond. Do forgo even your favorite wine. The FDA warns: Don’t drink alcohol while taking metronidazole and for at least one full day after finishing the medicine; together alcohol and metronidazole can cause nausea, stomach cramps, vomiting, flushing, and headaches.

Keep In Mind…

While there’s no cookie-cutter approach one can take with medication use, this list is a general attempt to create awareness around the idea that there could be some potential food interactions that anyone on medication should consider.

“For food interactions, patient awareness has to play a big role. Be aware of telling your doctor about things you eat, or medicines and supplements you may be taking from over-the-counter, the grocery store or health food stores, since they too can interact with the medicines and the food,” says Jackson-Hammond. Nothing is done in a vacuum. With chronic illnesses, people tend to be on multiple drugs. It’s all quantity related. If you are careful about the dosage of the medicine, as well as the quantity of the foods and drinks you imbibe, everything should be OK.”

Has your diet ever caused a problem with your medication? Tell us about it in the comments below.