CAN A GRAPEFRUIT
KILL ME?
Today more than 4 billion
prescriptions are written
in the U.S. each year, and
the average American will
swallow 3.4 pills per day.
Even for a mere common cold, people
can obtain a dozen drugs that can be
taken at home without a prescription.
The problem: No matter how harmless an
active ingredient is—when it interacts with
another substance, a chemical reaction will
take place. The consequences of this can
be serious: Drugs can transform, cancel
each other out, induce the opposite of
the desired effect, or become so strong
that they turn into a deadly poison. It’s a
game of Russian roulette that doctors
have been cautioning about for years—
especially with regard to self-treatment.
But what frequently goes unmentioned
is that drugs don’t just react with other
medicines—they react with anything that
has a chemical infl uence on the body.
And that includes food.
The extent to which physicians ignore
this risk is plain to see in the day-to-day
operations of a doctor’s offi ce. There the
eating habits of patients are usually not
surveyed, even though the infl uence of
foods on the metabolism—the body’s
own chemistry set—is indisputable. The
same is true for standardized patient
forms. These forms usually only inquire
about things like pre-existing conditions,
medication intake, or pregnancies. But
what about food? No chance! And this is
often the case though doctors know that
even a seemingly innocuous food like
fruit can quickly become dangerous. For
example, furanocoumarins—compounds
contained in citrus fruit like grapefruit—
affect the way medicines break down in
the human body. This can quickly turn a
harmless dose into a hazardous dose.
This drug interaction has even claimed
the life of a 29-year-old American man:
He took an antihistamine medication for
his hay fever and tried to increase its
strength with a glass of grapefruit juice.
He ended up raising the concentration of
the drug terfenadine in his blood thirty-
fold, which lead to circulatory collapse.Beer, salami, or mature cheeses can
be similarly dangerous: As these foods
age, they build up large amounts of the
blood pressure–raising agent tyramine.
Simultaneously using monoamine oxidase
inhibitors—for example, to treat anxiety
or depression—disturbs the breakdown
of tyramine. Consequences: headaches
and severely increased blood pressure.
Another example affects the 25 million people
who suffer from asthma in America. Some
asthma medicines contain theophylline.
If the substance comes into contact with
black pepper, it reacts with piperine—anaturally occurring chemical compound
(alkaloid) in pepper—and this raises the
level of theophylline in the body. Possible
symptoms include heartburn, agitation,
and cardiac arrhythmia.“Around two percent of all
hospital stays are the result
of interactions.”
PROFESSOR WALTER E. HAEFELI,
UNIVERSITY HOSPITAL HEIDELBERGideasanddiscoveries.com 63 Mar 2017