Do you worry about grapefruit? This
is not a strange question if you take a statin.
I say: enjoy
grapefruit with your statin.
Do you take a statin? Do you like
grapefruit or grapefruit juice? Then read on.
There are 7 statins on the market.
They all lower the LDL cholesterol and are prescribed to reduce the risk of
cardiovascular disease. These statins are listed below with the brand name in
the U.S. given in parentheses:
·
atorvastatin (Lipitor)
·
fluvastatin (Lescol),
·
lovastatin (Mevacor)
·
pitavastatin (Livalo)
·
pravastatin (Pravachol)
·
rosuvastatin (Crestor)
·
simvastatin (Zocor)
If you take a statin, you may have
seen warnings or alerts about eating grapefruit or drinking grapefruit juice. Those warnings imply that drinking grapefruit juice anytime during the day even hours apart from
when you take your statin may be deadly.
These alerts are almost everywhere.
And I believe they are way overblown and not based upon sufficient scientific or
clinical evidence.
Only three of the above statins
have warnings regarding eating grapefruit or drinking grapefruit juice while
taking the statin. Those 3 statins are: atorvastatin (Lipitor), lovastatin, and
simvastatin.
The official prescribing
information for these 3 statins cautions about drinking more than a quart a day
of the grapefruit juice.
Wow that’s a
lot! There are not going to be too many people doing that.
But what if you’re a little weird
and do drink more than a quart a day of grapefruit juice and also take
atorvastatin which is now available as a generic? Or, what if you love
grapefruit and eat 3 a day and also take simvastatin?
How risky is this?
Well it turns out that this whole
issue might be important but it is probably very much exaggerated.
Or to put it another way it is
likely clinically insignificant.
The chemical components in many
foods affect how our body handles or processes the chemical molecules in drugs.
Grapefruit is one of those foods that contain substances that affect how are
body processes some of the statins.
The liver and kidneys are the main
organs that metabolize, breakdown, process or eliminate the chemicals in drugs
and the many chemicals that make up our foods. Remember food is composed of
chemical molecules too.
Food is digested in our small
intestines. And substances that make up our food get into the bloodstream from
our intestines.
Well, it turns out that besides the
kidneys and liver, our intestines also change and process chemical substances
from our medications. The intestines are not just for digestion. They also process chemical molecules.
Grapefruit juice has substances
that affect how the intestines process many drugs.
Those effects vary
between people.
And these effects of grapefruit are also
difficult to predict and very complicated.
It appears that some substances,
called furanocoumarins, in grapefruit juice may reduce intestinal CYP3A4 an
enzyme that breaks down many drugs.
Grapefruit may also reduce uptake
into the bloodstream of substances by acting on OATP1A2, a transporter protein.
And last, grapefruit may affect
blood levels of drugs by affecting a substance called P-glycoprotein.
P-glycoprotein helps the body eliminate drugs from cells.
Most of the scary alerts about
grapefruit and statins arose because of a study done out of one center in Finland.
That study used a 60 milligram dose of simvastatin which is now above the recommended
maximal dose of 40 milligrams. In addition, that study had the 10 volunteers
drink 200 milliliters of double strength grapefruit juice three times a day.
That amount of grapefruit juice is equivalent to about 40 ounces or 1 and ¼
quarts of single strength grapefruit juice daily!
In this study there was an increase
in the blood level of simvastatin. The study was conducted over only 2 days.
Another, more recent study
conducted by these same researchers also showed an increase in blood levels of
simvastatin but the volunteers in this 3 day study drank only only 200
milliliter (about 7 ounces). The amount (expressed as area under the curve and
peak concentration) of the simvastatin was increased on average about 3-4 times
above the usual.
And when the simvastatin is taken24 hours after high dose grapefruit juice, no meaningful increase in
simvastatin levels were seen.
The concern is that there may be an
increased risk of muscle damage with the high blood levels of the statin. Muscle
damage or myopathy is the only real risk of statin use.
Rhabdomyolysis is a severe form of muscle damage. Rhabdomyolysis is rare.
Rhabdomyolysis occurs in less than 2 persons out of 100,000 who take statins for a year.
Doctors can reduce the chances of a patient getting rhabdomyolysis by understanding factors that increase risk.
Rhabdomyolysis is a severe form of muscle damage. Rhabdomyolysis is rare.
Rhabdomyolysis occurs in less than 2 persons out of 100,000 who take statins for a year.
Doctors can reduce the chances of a patient getting rhabdomyolysis by understanding factors that increase risk.
No clinical reports of problems
have been described in humans when grapefruit juice is taken with statins.
And remember, this is primarily a
possible issue with simvastatin and lovastatin.
In a recent study, daily
drinking of grapefruit juice did not have a significant effect on drug levels
of atorvastatin despite the official prescribing information
Grapefruit juice should be an
important concern in those people on immuno-suppressants, those on chemotherapy
and those on drugs for HIV infection.
There are also certain medications that you might be taking that could increase your risk of statin myopathy whether you drink grapefruit juice or not.
Your doctor should know about those and take one of three steps:
reduce your statin dose or change you to a safer statin or change the other medication.
There are also certain medications that you might be taking that could increase your risk of statin myopathy whether you drink grapefruit juice or not.
Your doctor should know about those and take one of three steps:
reduce your statin dose or change you to a safer statin or change the other medication.
For most people, you can
enjoy grapefruit with your statin.
Check with your doctor if you have questions. And direct him to this post if he is not sure.
Check with your doctor if you have questions. And direct him to this post if he is not sure.
