Physicians and pharmacists are super busy these days. Some pharmacists have confided to us that they feel like they are in an I love Lucy skit like this one where Lucy and Ethel wrap chocolates. Patients may feel like they are on a conveyer belt when it comes to taking pills. Instructions about how to take medicine can be very confusing. That is especially true when it comes to statins. For example, can you take simvastatin or atorvastatin with grapefruit juice? It’s much more complicated than you might think.
Grapefruit and Drug Interactions Stir People Up:
We wrote a newspaper column 25 years ago that made many doctors mad.
Here’s what stirred up the hornet’s nest:
“Physicians and pharmacists often complain that patients don’t take their medicine properly. They cite statistics that 125,000 people die every year because of medication mistakes. But they don’t admit that they are partly to blame. Check the average prescription and you will find instructions that are inadequate, ambiguous or incomplete.”
Bruce Dodged the Grapefruit Bullet:
We went on to describe the story of Bruce, a professional photographer. He had to be both focused and calm to get the best shots for his news magazine. Because Bruce suffered from allergies, he was vulnerable to sinusitis.
His doctor prescribed Seldane to control the allergies and Cipro for an ear infection. The only instructions on either prescription were:
“Take two times a day.”
Bruce liked a strong cup of coffee to get going in the morning. He was surprised when he was wired for hours after his usual double cappuccino. He felt jittery and uncomfortable, and had trouble holding the camera steady. No one had told him that Cipro would boost caffeine levels in his system and lead to a prolonged effect.
Although unsettling, this interaction was not serious. But Bruce unwittingly flirted with death when he swallowed his Seldane with grapefruit juice. The heart palpitations that resulted could have led to a lethal change in heart rhythm.
Grapefruit and Other Drugs:
In that decades-old column we added this warning about grapefruit:
“Components of grapefruit juice affect an enzyme that is responsible for the metabolism of a number of drugs, including Seldane, Adalat, Procardia and Plendil. Levels of these medications could build up unexpectedly and lead to adverse reactions if they are taken with grapefruit juice.
“We can’t blame Bruce’s doctor or his pharmacist for not warning him about these interactions. The Food and Drug Administration has been lax about requiring companies to do the proper tests and inform health care providers about food and drug interactions. Many drugs are less effective if they are taken with food. Others may become quite toxic if taken with the wrong stuff.”
The Nifedipine (Procardia) Nastiness:
It wasn’t long after writing that newspaper column that we received this nasty note:
“My doctor says your caution about grapefruit juice is nonsense. I take Procardia for high blood pressure and angina. I love grapefruits and used to have one with breakfast until I read in your column that grapefruit juice affects Procardia.
“How can something as simple as grapefruit juice cause any problems with my blood pressure medicine?”
In those days many health professionals did not believe grapefruit could pose a problem. We went on to describe the origins of the grapefruit-drug interaction discovery this way:
“Researchers at the University of Western Ontario, Canada, stumbled upon the grapefruit juice interaction by accident. They were investigating the effect of alcohol on drug metabolism and used grapefruit juice to disguise the taste of ethanol.
“To their surprise, grapefruit juice dramatically boosted blood levels of the blood pressure drug Plendil (felodipine). Further research has shown that nifedipine (Adalat, Procardia) blood levels are also increased by grapefruit juice. Headaches, lightheadedness and facial flushing were side effects of this combination.”
Atorvastatin with Grapefruit Juice:
Fast forward to 2018. The grapefruit story remains confusing to many people. Is it safe to take simvastatin or atorvastatin with grapefruit juice? This reader thinks he knows.
Q. I’ve heard that some people take their atorvastatin with grapefruit juice to boost its effectiveness. My wife and I both take this cholesterol-lowering drug, and the first thing our cardiologist told us was to never drink grapefruit juice while we are on this medicine. Too many people don’t pay attention to the precautions offered with their drugs and then they have bad interactions.
A. Certain statins (atorvastatin, lovastatin and simvastatin) interact with grapefruit juice. Compounds in grapefruit inhibit an enzyme in the digestive tract that breaks down these medications. That means blood levels of the medication will be higher than expected.
Researchers calculated that taking atorvastatin with grapefruit juice increases blood levels by about 80 percent (American Journal of Medicine, Jan. 2016). Simvastatin and lovastatin are increased by 260 percent.
The investigators suggest that the reductions in cholesterol and heart disease risk are greater than the harms.
“Grapefruit juice should not be contraindicated in people taking statins.”
That said, no one should consider this approach except under strict medical supervision. Higher levels of statins in the bloodstream may increase the risk of serious side effects.
How Many Drugs Are Affected by Grapefruit?
In 2013 Dr. David Bailey and his colleagues wrote this in CMAJ (March 5, 2013).
“Our research group discovered the interaction between grapefruit and certain medications more than 20 years ago. Currently, more than 85 drugs, most of which are available in Canada, are known or predicted to interact with grapefruit. This interaction enhances systemic drug concentration through impaired drug metabolism.
“Many of the drugs that interact with grapefruit are highly prescribed and are essential for the treatment of important or common medical conditions. Recently, however, a disturbing trend has been seen. Between 2008 and 2012, the number of medications with the potential to interact with grapefruit and cause serious adverse effects (i.e., torsade de pointes, rhabdomyolysis, myelotoxicity, respiratory depression, gastrointestinal bleeding, nephrotoxicity) has increased from 17 to 43, representing an average rate of increase exceeding 6 drugs per year. This increase is a result of the introduction of new chemical entities and formulations.”
Learning More About Statins like Atorvastatin and Grapefruit Juice:
If you would like to read more about grapefruit and drug interactions you can access our free Guide to Grapefruit Interactions.
FAQs About Grapefruit:
Does fresh grapefruit have the same effect as grapefruit juice?
How long does the grapefruit effect last?
Can I have my grapefruit in the morning and take my pills safely later in the day?
Do oranges or other citrus fruits interact in a similar way?
Do I have to give up grapefruit completely if it interacts with my medicine?
Can I use the grapefruit effect to reduce my dose of medicine?
Get answers to those frequently asked questions at this free link.
You can also learn more about food and drug interactions in general at this free link.