The number of common prescription drugs that can interact with grapefruit, with potentially serious or even fatal results, is climbing sharply. Grapefruit juice can interact with more than 85 oral medications, including certain cholesterol-lowering statins, cancer medications, antibiotics, anti-depressants, pain medications, heart drugs and other widely used pills.
Potentially Fatal Interactions
Between 2008 and 2012, the number of drugs with the potential to cause the most dangerous interactions, including acute kidney or respiratory failure and GI bleeding, has jumped from 17 to 44 drugs. Half of these drugs actually can cause sudden death, if taken within hours of drinking grapefruit juice (or eating the fruit).
Although the tart citrus can interact with more than 85 drugs, some interactions are unlikely to cause serious harm. Here’s a closer look at the research and what you need to know to protect your health. A number of other foods, including deli meat, milk and even candy, can also react adversely with certain drugs.
Why Are Grapefruit-Drug Interactions So Dangerous?
Grapefruit disrupts the body’s metabolism of certain drugs because it contains compounds called furanocoumarins that interfere with enzymes that break down the drugs in the gut. That means more of the drug stays in your body, which could cause it to build up to toxic or even lethal levels. The same compounds are also found in other citrus fruits, including Seville oranges (the kind used in marmalade), limes and pomelos, but not in regular oranges. These adverse reactions can occur many hours after someone consumes grapefruit or its juice, and as little as one glass of grapefruit juice can be enough to trigger dangerous interactions, the researchers report.
Which Drugs Interact with Grapefruit?
- statins (Zocor, Lipitor)
- calcium channel blockers (Procardia, Nimotop, Sular)
- anxiety (BuSpar)
- heart arrhythmias (Cordarone)
- depression (Zoloft)
- seizures (Tegretol, Carbatrol)
- malaria (quinine)
- insomnia (Halcion)
- pain (oxycodone)
Which Other Foods Interact With Medication?
Among the other common foods that affect absorption or effects of medication are:
Black licorice. Many forms of black licorice contain a sweet substance called glycyrrhizin, which can increase the toxicity of certain drugs or worsen side effects.
- Lanoxin (a treatment for heart failure and irregular heartbeats) can dangerously raise the risk of toxic side effects.
- ACE inhibitors and diuretics used to regulate blood pressure, may increase adverse effects from insulin, and boosts the potency of corticosteroids.
- Birth control pills developing high blood pressure and low potassium levels after eating licorice.
Leafy green vegetables. Kale, spinach, Brussels sprouts, and cabbage can make medication that combats blood clots less effective. That’s because these foods are high in vitamin K, a crucial nutrient for clot formation, while the goal of anticoagulant therapy is to slow down production of vitamin K to reduce clot risk. In effect, these foods counteract the drug’s desired effect.
- Warfarin (Coumadin). If you take this drug, it’s not necessary to avoid leafy greens—instead doctors advise eating a consistent amount week to week, so your dose of warfarin can be calibrated accordingly.
Milk. Milk and calcium supplements can interfere with absorption of certain infection-fighting drugs, if taken together. The best solution is to wait a few hours after taking these drugs before drinking milk, popping a calcium supplement, or taking antacids (which can also contain calcium).
- Tetracycline and fluoroquinolones (a class of antibiotics that includes Cipro, Levaquin and Avelox).
Alcohol. Mixing alcohol with certain medications, including both prescription and over-the-counter drugs, can have a wide range of harmful effects, from nausea and vomiting to drowsiness, internal bleeding, liver damage, sudden changes in blood pressure, impaired breathing, and loss of coordination.
- OTC cold, cough, flu and allergy remedies
- Drugs for angina (Isodil)
- Anxiety and epilepsy (Ativan, Klonopin, Xanax,)
- Arthritis (Celebrex, Voltaren)
- Depression (Celexa, Effexor, Lexapro)
- Diabetes (Glucophage, Orinase)
- Enlarged prostate
- High blood pressure
Aged, cured or pickled foods. Aged cheeses like cheddar or Swiss, cured meats, and sauerkraut contain tyramine, an amino acid that sparks one of the most feared drug-food interactions when combined with certain antidepressants. The mixture can cause facial flushing, sweating, sudden rise in blood pressure, irregular heartbeats and brain hemorrhage. Tyramine is also found in certain types of wine, such as Chianti, sherry and Riesling.
- Monoamine oxidase inhibitors (MAOI) for depression
- Antibiotics Zyvox and isoniazid.
Chocolate. The caffeine in chocolate (and other caffeinated foods) can trigger severe jitters or tremors when combined with certain meds, and packs a double whammy by irritating the stomach lining, amplifying the side effects of drugs likely to cause nausea. Chocolate also contains some tryamine, the culprit in a food-drug interaction that killed a University of Wisconsin Hospital and Clinics patient.
- MAO inhibitors for depression
- Some antibiotics
- Narcotic painkillers like Vicodin and Percoset
- Asthma medications
- Stimulants, such as Ritalin.