Alex Evans works in community pharmacy in Kihei, Hawaii. He is also a PADI assistant scuba instructor.
With the holiday season in full swing, you will want to remind your patients of these 4 hazardous holiday food and drug interactions.
4 Dangerous Holiday Food-Drug Interactions
Warfarin inhibits vitamin K epoxide reductase complex 1, which converts vitamin K epoxide to the active vitamin K reduced. Vitamin K is a necessary cofactor in the activation of several coagulation factors and of anticoagulation factors protein C and S. Blocking vitamin K activation leads to anticoagulation.
Here is a case report of a man who drank cranberry/apple juice and went from a therapeutic INR of 2-3 to 6.45. However, case reports do not establish causation and can have numerous confounders that make conclusions difficult.
There has been 1 prospective trial that failed to show an association between cranberry and increased INR when patients consumed up to 240 mL (8oz) of cranberry juice per day. The authors argue that previous case reports were based on the consumption of large amounts of cranberry and that the patients in those case reports also had underlying conditions, leading to potential confounders. Perhaps the best advice to warfarin patients is to enjoy their cranberry dishes but to limit how much they consume.
This risk of augmented effects is serious enough that in 2016 the FDA required boxed warnings for all opioid and benzodiazepine medications. As for holiday indulgence-American Addiction Centers reports that 23% of men and 18% of women binge drink during the winter holidays, and 47% of men and 40% of women binge drink on New Year’s Eve. An average of 4.4 drinks are consumed on New Year’s Eve and 3.1 during the winter holidays. This makes for a dangerous combination and a good practice would be for both pharmacists and physicians to educate patients on the risks during this time of the year.
One study that looked at young, healthy adults who were normotensive found an increased likelihood of having a larger left ventricular mass in those who had a higher sodium and lower potassium intake. Again, many of our patients are not going to focus on their health until New Year’s resolutions come around, so now is a good time to reinforce moderation during the holidays, including with salt intake.
In patients using these medications at the generally prescribed doses, dietary restrictions aren’t completely necessary; however, there have still been case reports of patients developing severe hypertension at these doses. Just as in the cranberry example, moderation is key – the package insert for rasagiline, for example, states that patients should avoid foods “very high…(eg, >150mg) in tyramine.”
It’s the season again! The family is coming over (we’re busy filling up the anxiety medications at the pharmacy!), there is lots of great food and plenty needs to get done. The last thing on most of our patients’ minds at this time of the year is their health (other than getting those procedures in before the deductible starts over).It could be a good time, perhaps during a routine office visit, to remind patients about dangerous holiday food-drug interactions. Here are my top picks to help keep your patients safe during their holiday feasts.
