Your Medications and Your Breakfast Could Be a Deadly Combination

02/28/2014 10:57 am ET | Updated Apr 30, 2014

Do you enjoy a glass of grapefruit or cranberry juice in the morning when you take your medication?

Don't think about drinking these juices if you take certain medications.

If you do, it could lead to deadly consequences. Those specific juices could increase your medication to toxic levels.

A few weeks ago it was National Drugs Fact Week. Although this week was intended to shatter myths about drugs and drug abuse particularly for teenagers, I want to highlight something a little bit different.

Instead, I want to discuss your medications (which you might not realize are actually drugs) for diabetes, high blood pressure, high cholesterol or infections to name just a few.

What are the facts that you need to know to take your medications safely and effectively?

First up is grapefruit and grapefruit juice.

Dr. David Bailey, who is a Canadian researcher, has published a list of 85 medications affected by grapefruit. Of 85 medications, 43 have the potential to cause life-threatening reactions if taken with grapefruit or grapefruit juice.

You are at risk for potentially life-threatening reactions by eating grapefruit or drinking its juice:

• If you are diabetic and take Prandin (Repaglinide) or Onglyza (Saxagliptin).

• If you have an infection and take the antibiotic Erythromycin.

• If you have gout and take Colchicine.

• If you take cholesterol lowering drugs such as Lipitor (Atorvastatin), Mevacor (Lovastatin) or Zocor (Simvastatin).

• If you have heart problems including an irregular heart beat, congestive heart failure or high blood pressure and take Losartan, Nifedipine, Amlodipine, Verapamil, Quinidine or Amiodarone.

• If you have pain or anxiety and take the CNS Agent Carbamazepine or Oxycodone.

Also included on the list are medications for cancer, psychiatric drugs, immunosuppressant medications for transplant patients, AIDS medications, some BCPS or estrogens.

How do these serious interactions occur?

Most pills that we take are broken down by an enzyme (CYP3A4) in the intestines. Actually, only a small amount of the active medication is absorbed into your system when you take your pill.

Grapefruit contains chemicals (furanocoumarins) that block the enzyme (CYP3A4) and much more of the medication is absorbed into your system than if you had not consumed grapefruit juice. Then the levels of the medication increase to dangerous levels.

An example of the effect of grapefruit on a medication was reported in the NYTimes Well Blog ( The blog writer gave the example of a person taking the cholesterol lowering drug simvastatin (Zocor) who consumed a 6.7 ounce glass of grapefruit juice daily for three days. That person could see blood levels of the simvastatin triple, increasing the risk kidney damage and a condition called rhabdomyolysis, which is a dangerous breakdown of muscle.

What are these potentially life-threatening interactions that can occur?

In some cases a deadly irregular heart beat, called torsade de pointes, can occur with kidney damage. Bone marrow, blood cells and muscles may be damaged. In other cases, the interaction can cause one to stop breathing.

What are other fruits that can interact with medications?

Dangerous interaction can be caused by other citrus fruits, including Seville oranges, limes, pomelo, pomegranate and even marmalade.

There are more drug facts that you must know.

Interactions with cranberry juice have also been reported, and this has occurred primarily with warfarin (Coumadin). Remember, Coumadin thins the blood and too little or too much thinning can have devastating effects.

If you take the antibiotics, tetracycline, doxycycline or minocycline with dairy products (milk, cheese, yogurt, ice cream) the medications will not be absorbed into your system and they will not work.

This means that your infection may not improve. If you take those medications for acne, the acne will not respond as you had hoped.

What can you do?

Always read the information that the pharmacy gives you about the medication.

Also read the stickers that are attached to your bottle.

Discuss with your doctor or health care provider what foods your medications can and cannot be taken with.

Medications are drugs and knowing how to take them properly involves more that just the right time of day, rather what to consume them with is just as important.