Last Update: 3 June 2020 by Marc Woodard.

Many don’t realize some foods can interact badly with prescription drugs when consumed together. Those that fail to read the dietary warning’s listed on specific pharmaceutical labels, or disregard the prescription use instructions can cause increased health risk.

Listed below are 7 common prescription drugs and foods that when consumed together can increase health risk and/or cause severe ill-health side effects. There are many chemical reactions that occur within the body to keep the metabolism and overall physiology balanced. And when using pharmaceuticals it is important to understand, even the most benign appearing foods can cause an unhealthy chemical reaction.

One only needs to understand everything we put into our bodies causes some kind of chemical reaction. Therefore it is important to realize, if you take any pharmaceutical, ask your doctor and/or pharmacist if there is any food that would cause an ill-health affect or risk to overall health when taken together.

Listed are commonly prescribed medications & foods that don’t interact well.

1. Anti-depressants SSRI’s (Selective Serotonin Reuptake Inhibitors) Lexapro, Prozac, Paxil, Zoloft, etc. MAOI’s (Monoamine Oxidase Inhibitors) – Isocarboxazid, Phenelzine, Selegiline, Tranylcypromine, etc. Their related generic counterparts are: Marplan, Nardil, (Emsam, Eldepryl, Zelapar) and Parnate.

Drug treatment purpose: Anti-depressants are effective in treating depression, panic and other anxiety disorders. They also require special considerations with regard to diet. MAOI’s are normally used when other anti-depressants fail. When used as prescribed they will boost mood by improving brain cell communication.

Side effects: Diarrhea, dry mouth, sleepiness, lightheadedness, dizziness, low blood pressure, nervousness, muscle aches, insomnia, weight gain, sense of taste, hampered sexual drive, erectile dysfunction, difficult urinating, tingling, or prickling sensation on skin. If removed from anti-depressants too fast the following withdrawal effects are likely: insomnia, flu-like symptoms, fatigue, irritability and anxiety may follow.

Non-compatible foods: Aged cheeses, pickled, or fermented sausages (pepperoni, salami), luncheon meats, beef liver, chicken liver, yeast-containing foods and beverages that have the compound tyramine [protein containing foods] in them. This compound has an effect on blood pressure. If the bodies MAO (Monoamine Oxidase) enzyme is inhibited by MAOI medication, it is necessary to avoid the foods that contain this compound. If this diet restriction is not followed, then blood pressure can increase towards critically unhealthy levels.

Health risk when prescription and non-compatible foods are taken together: High levels of tyramine in the body can lead to high blood pressure, heart arrhythmia and brain hemorrhage.

2. Anti-anxiety – Benzodiazepines are the most common anti-anxiety drugs, e.g., Ativan, Klonopin, Valium, Xanax, etc., and Generic: lorazepam, clonazepam, diazepam and alprazolam are all sedatives and bind with the brains natural sedatives to calm you down.

Drug treatment purpose: To help relax and reduce anxiety. Anti-anxiety drugs are also known as tranquilizers. Anti-anxiety medications work by slowing down the central nervous system [reduced brain activity] and have a relaxing effect on the mind and body. They are also prescribed for sleeping and muscle spasm disorders. Often antidepressants will be prescribed to relieve symptoms of anxiety.

Known side effects: Addiction, inability to focus-learn, uncoordinated, clumsiness, confusion, disorientation, blurred vision, upset stomach, lightheadedness, sleepy, impaired judgment, nausea, memory loss. Long term users of these medications also experience depression. High dosages and long term use will likely increase suicidal thoughts and feelings. Benzodiazepines can also cause the opposite of a calming effect like mania, aggressive behavior, or hostility, rage and even hallucinations.

Non-compatible foods: Alcohol. When these drugs are mixed with alcohol the sedative properties on the brain and body is amplified. Not only do you feel more drunk, but more tired and forgetful. Coffee and drinks with caffeine in them affects anti-anxiety and asthma medications.

Health risk when prescription and non-compatible foods are taken together: Your breathing rate is significantly slowed down and risk of respiratory failure increases.

3. Antibiotics – Monodox, Dynacin, Sumycin, Cipro, Levaquin, etc. Generics: minocycline, tetracycline and doxycycline, etc. This listing represents a few of many antibiotics that could be prescribed.

Drug treatment purpose: Antibiotics are used to kill bacterial infections. They are not effective against fungal (ringworm or vaginal yeast infection), flu, or the common cold.

Side effects – Antibiotics are relatively safe when used appropriately. However, like any medication unwanted side effects do occur. If you experience any skin rash, hives, wheezing, anaphylaxis (shortage of breath), swelling of lips, tongue or face seek medical attention immediately.

Non-compatible foods: Dairy products have calcium in them. Calcium tends to bind with the antibiotics if a dairy product is consumed within a two hour window after taking the medication. Vitamins and Antacids can also decrease the efficiency of antibiotics. For example, ciprofloxacin an antibiotic used to treat urinary tract and abdominal infections among other things; when mixed with antacids becomes less effective when it binds to magnesium and calcium.

Health risk when prescription and non-compatible foods are taken together: This binding prevents the antibiotic from absorbing into the body to fight an infection rendering various antibiotics useless. When this happens the medication stays in the intestine and leaves the body at the next bowel movement. Yet there are other antibiotics used for strep throat and ear infections where dairy products have no impact on those medications.

4. High blood pressure, or anti-hypertension medications – Univasc, Zestril and Monopril can raise your potassium levels. Common generics: Hygroton, Lozol, Mykrox, Diuril, Lasix, Esidrix, etc. There are many specialized medications that are designed to treat both diuretic and high blood pressure cases.

Drug treatment purpose: To lower blood pressure and reduce blood clotting risk. Many classes of blood pressure medications include a diuretic treatment component. These medications help to rid the body of excess water and sodium and help to control blood pressure. Diuretics are often used in combination with other medications like anti-clotting prevention treatment that use aspirin and Plavix. When patients are at high risk of stroke or heart attack, doctors often prescribe Plavix as an anti-platelet drug for blood clotting prevention. The first line of attack is aspirin. Both anti-clotting and blood pressure medications may likely be prescribed together, but not always.

Known side effects: Gout, increased blood sugar levels, leg cramps, weakness, impotence may occur.

Non-compatible foods: Limit foods high in potassium like bananas, salt substitutes with potassium, spinach, leafy greens and sweet potatoes. Eating a banana once a day, or leafy green the next should be ok. But you’ll want to confirm diet and frequency of consumption with your prescribing physician.

Health risk when prescription and non-compatible foods are taken together: Too much potassium in the body can cause your heart to beat irregularly and in severe cases can cause cardiac arrest. Also, two foods that can keep blood clotting medications from working are garlic and ginger. They can cause excessive bleeding as they both have high doses of blood thinning agents in them.

5. High cholesterol – Statin drugs (blood cholesterol lowering medications) include: Lipex, Mevacor, Zocor, Crestor, Vytorin or Lipitor, to include generics like simvastatin, lovastatin, or atorvastatin, etc.

Drug treatment purpose: Lower High Blood Cholesterol.

Known side effects and health risk: As of recent studies, the following health risks are possible; memory loss, diabetes and muscle pain. The food and drug administration has officially linked statin drugs with forgetfulness, confusion and increased blood sugar levels that would be of concern for diabetics. Liver injury is also possible and is rare.

Non-compatible foods: Some cholesterol medications can be affected by grape fruit juice or the fruit. It is the inhibiting properties of this fruit that keeps the intestine and/or liver from breaking down the drug and increases the risk that the drug will accumulate in the body and become toxic. It is the citrus that blocks the enzyme in the intestines and prevents the metabolism of these drugs. The active component in this fruit is not yet known. Check with your prescribing doctor about grapefruit products in the diet. There are some statin medications that are not influenced by this fruit. It is also true some immune drugs and allergy drugs like Allegra are affected by grapefruit.

Health risk when prescription and non-compatible foods are taken together: Grapefruit and its juice should be avoided when using heart medicines and a number of other prescriptive drugs for cardio and immunological health related problems. Be sure to consult with the prescribing physician with foods you should consume when on these medications.

6. Blood thinner – Coumadin (generic: warfarin) Aggrenox, Aspirin, Jantoven, Heparin, Lovenox, Plavix, etc.

Drug treatment purpose: The job of blood thinners is to thin the blood for patients that are high risk of heart attack, or developing blood clots.

Known side effects: Each medication listed can cause a combination of the following side effects; Nausea, irritated stomach, abdominal pain, diarrhea, headache, dizziness and indigestion. Coumadin and Heparin can cause serious bleeding inside the eye and intestine, or cause bruising, blood in the urine, nose bleeds. Other problems include kidney function, difficulty breathing and muscle aches.

Non-compatible foods: Since Vitamin K (thickens blood) is found abundantly in leafy greens, they can block the effects of the blood thinners. Leafy greens that can affect of blood thinners are Brussels sprouts, collard greens, spinach, cabbage, lettuce, alfalfa sprouts, asparagus, broccoli, cauliflower, parsley, kale, Swiss chard and Green tea. Other foods that may impact blood thinner medications include: cranberries, as well as the juice, garlic and ginger. They can actually increase the blood thinning properties of the blood thinners that could amplify their effect.

Health risk when prescription and non-compatible foods are taken together: Increased risk of stroke and heart attack.

7. Thyroid – Synthroid, Armour thyroid, Levoxyl, Cytomel, etc. Generic: Levothyroxin, thyroid desiccated, levothyroxine, liothyronine, etc.

Drug treatment purpose: Used to regulate the thyroid glands to normalize hormone functions throughout the body when they fail to produce enough thyroid hormone. Effective treatment can increase energy, mood disposition and body weight regulation. To include supports male and female characteristic traits.

Known side effects: Thyroid medications do not cause side effects if taken in the correct dose.

Non-compatible foods: Tofu, soymilk (soy products) and walnuts can prevent your body from absorbing the thyroid medication. It may not be necessary to give up these foods, but let your physician know about your dietary preferences. It is very possible your soy diet preference can be resolved with a modification of dose.

Health risk when prescription and non-compatible foods are taken together: Weight gain, obesity and other ill-health and disease complications.

References,

American Heart Association. Types of Blood Pressure Medications.

Ankrom, Sheryl. Dietary Precautions While Taking MAOIs. Former About.com Guide, updated June 17, 2009. 

Club Red. Some Foods and Medications Just Don’t Mix. January 2012.

Drugs.com. Common Side Effects, Allergies and Reactions to Antibiotics.

Drugs.com. Underactive Thyroid (Hypothyroidism) Medications.

Harris, Gardiner. Safety Alerts Cite Cholesterol Drugs Side Effects. The New York Times. February 28, 2012.

Helpguide.org. Anxiety Medication.

Rodgers, Linda. Foods and Medications that Don’t Mix. Grand Parents.com

Mayo Clinic Staff. Depression (major depression). Monomine Oxidase Inhibitors (MAOIs).

NBCNews.com. Foods to Avoid When You’re Taking Meds. 26 October 2006.

Vega, Jose M.D., Ph.D. Side Effects of Coumadin, Plavix and Other Blood Thinners.  About.com.

WebMD.com. Hypothryroidism.

Woodard, Marc. 41 Drugs to Die For. Mirror Athlete Fitness Secrets. 24 October 2010.

Woodard, Marc. Defeat Anxiety and Panic Attacks. Mirror Athlete Fitness Secrets. 24 November 2010.

Woodard, Marc. How to Deal with Depression. Mirror Athlete Fitness Secrets. 25 August 2008.

Woodard, Marc. The Thyroid is a Powerful Weight Regulating Gland. Mirror Athlete Fitness Secrets. 21 May 2012.

Author: Marc T. Woodard, MBA, BS Exercise Science, ARNG, CPT, RET. 2013-20 Copyright. All rights reserved, Mirror Athlete Inc., www.mirrorathlete.org, Sign up for your Free eNewsletter.