Americans take a lot of pills. According to the U.S. Food and Drug Administration (FDA), at least 100,000 Americans die each year from reactions to properly prescribed prescription drugs. At this point, most of us know enough to read the warnings about side effects and interactions with other pharmaceuticals. But what you may not know is that sometimes the villain responsible for throwing your medication entirely out of whack comes not from your pharmacy, but from your friendly neighborhood grocery store.
Grapefruit juice is one of the best known culprits in food/drug interactions. Take note: It is only the juice, and not the whole fruit, that causes these reactions. Thirty-two ounces or more per day of grapefruit juice can significantly boost the levels of certain statins in the blood, putting patients at elevated risk for statin-related side effects. One result can be muscle toxicity, which may manifest as myalgia, myopathy or rhabdomyolysis. Many other medications are also affected. Calcium channel blockers interact with grapefruit juice, increasing the risk of low blood pressure and dizziness on rising. Those who use Viagra or Cialis and guzzle grapefruit play Russian Roulette – they can unexpectedly encounter visual disturbances … or a boner that just won’t go away. And the list goes on: Estrogen-containing oral contraceptives, tricyclic antidepressants and Valium (along with other drugs that act on the central nervous system,) are all accelerated or diminished by grapefruit juice. If you have a heart arrhythmia, interactions are unpredictable. If you undergo an organ transplant? Avoid, avoid. Even antihistamines and cough suppressants can become dangerous.
The fortification of many drinks and juice cocktails with vitamin C seems like a great idea for extra antioxidants … until you combine them with Adderall and amphetamines, at which point a patient will experience a drastic acceleration of the drugs in your system. Conversely, the effect of some antihistamines can be diminished. If you have a child with attention deficit disorder or allergies, do not hand out juice with the medication.
Ever think that your doctor would tell you to avoid green leafy vegetables? Blood-thinning drugs such as warfarin (brand name, Coumadin) interfere with clotting factors that depend on vitamin K. Eating too many K-containing veggies, such as spinach, kale or collards, can decrease the ability of your medication to prevent clotting. But are those colorful healthy salads off your menu forever? Not if you are sensible and consistent. Problems arise from significantly and suddenly increasing or decreasing intake. So eat your greens in consistent amounts.
Natural black licorice (glycyrrhiza) can throw a wrench in the works by depleting the body of potassium while causing an increased retention of sodium. When potassium levels fall, it can greatly intensify the activity of digoxin, a medication used to treat heart failure, causing dangerous arrhythmia. Licorice can also increase susceptibility to blood clots. Note: Artificial flavors have none of the same problems as the natural form.
You may have never heard of Tyramine, but foods containing this amino acid can cause an increase in blood pressure. Those taking MAO inhibitors and medication for Parkinson’s disease should avoid chocolate, aged cheeses, smoked fermented meats, hot dogs, processed lunch meats, over ripe fruit, fermented soy products and pickled anything. Draft beer is also on the banished list, but canned and bottled beers are OK – whew!
Salt substitutes, supposedly a healthier choice than sodium, can cause heart failure in patients who take digoxin. There is a massive amount of potassium standing in for the salt, which decreases the effectiveness of digoxin. And anyone taking drugs such as ACE inhibitors, which themselves boost potassium, may see a dangerous increase in blood levels.
Those taking antibiotics or antimicrobial agents such as Quinolones should avoid dairy foods at least two hours before or six hours after their dose. The effect of these meds is dampened significantly by calcium. And take heed: More foods than ever before are now fortified with calcium. Check labels carefully, especially on bread and orange juice.
Caffeine is really a drug itself, but there are so many foods and drinks containing it that we don’t always realize it’s there. The antibiotic Ciprofloxacin boosts the effects of caffeine by inhibiting its metabolism. Oral contraceptives and prednisone also increase caffeine levels due to the same inhibiting quality. Theophylline, which shares a similar chemical makeup, is boosted when taken in tandem with caffeine; this may cause patients to experience adverse theophylline-related effects, such as jitteriness, insomnia and even cardiac arrhythmia.
One last warning: Please don’t make the mistake of thinking that simply because vitamins and herbal remedies originate in food and don’t require a prescription, you can treat them like M&M’s. Give alternative meds the same respect you would to pharmaceuticals, and always keep your doctor informed about any supplements you are taking.