Many drugs are broken down (metabolized) with the help of a vital enzyme called CYP3A4 in the small intestine. Grapefruit juice can
block the action of intestinal CYP3A4
, so instead of being metabolized, more of the drug enters the blood and stays in the body longer. The result: too much drug in your body.
Does grapefruit affect metabolism?
Scientific studies indicate that grapefruit and grapefruit juice
inhibit CYP3A4
, which metabolizes more than 65% of all drugs, as well as P-glycoprotein (P-gp) and a number of other metabolic enzymes and transporters.
How grapefruit or grapefruit juice inhibits the action of the drug?
Grapefruit juice causes inhibition of CYP 3A4 and thus serves to increase the bioavalability of the drug
by decreasing its pre-systemic metabolism
[10]. This action is in essence, similar to that caused by CYP-inhibiting drugs like itraconazole, ketoconazole and erythromycin [11–13].
How is grapefruit juice an inhibitor?
Grapefruit juice, a beverage consumed in large quantities by the general population, is an
inhibitor of the intestinal cytochrome P-450 3A4 system
, which is responsible for the first-pass metabolism of many medications.
Is grapefruit juice a CYP3A inhibitor?
Grapefruit juice
acts by inhibiting presystemic drug metabolism mediated by CYP3A isoforms in the small bowel
. The interaction appears particularly relevant for medications with at least a doubling of plasma drug concentration or with a steep concentration-response relationship or a narrow therapeutic index.
What meds should not be taken with grapefruit?
Examples of common medications that interact with grapefruit juice include certain
statin cholesterol
drugs such as atorvastatin (Lipitor), lovastatin, simvastatin (Zocor), felodipine (Plendil) and other calcium channel blockers, clarithromycin (Biaxin), and loratadine (Claritin).
What does grapefruit juice do to metabolism?
Many drugs are broken down (metabolized) with the help of a vital enzyme called CYP3A4 in the small intestine. Grapefruit juice
can block the action of intestinal CYP3A4
, so instead of being metabolized, more of the drug enters the blood and stays in the body longer.
Is grapefruit juice a cyp450 inhibitor or inducer?
Grapefruit juice is associated with the inhibition of
Cytochrome P450 enzyme system
, particularly the CYP3A4 enzyme
7
. The CYP3A4 enzyme is present both in the liver and intestinal mucosa.
What happens if you drink too much grapefruit juice?
Eating a grapefruit or consuming its juices while taking certain medications could lead to
gastrointestinal bleeding
, kidney failure, depressed breathing and sudden death, warns a new paper in the Canadian Medical Association Journal.
Is quinine in ruby red grapefruit juice?
The
juice or grapefruit itself contains valuable and natural quinine
, which is advantageous for the treatment of malaria. Quinine is an alkaloid with a long history of treating malaria, as well as lupus, arthritis and nocturnal leg cramps.
How much grapefruit juice causes a drug interaction?
One whole grapefruit or 200 mL of grapefruit juice
is sufficient to cause clinically relevant increased systemic drug concentration and subsequent adverse effects.
How long does grapefruit juice stay in your system?
One whole grapefruit or one glass of grapefruit juice is enough to alter how these medications affect you. Its
effects last several days
. Grapefruit’s ability to affect medication lasts for 1–3 days. Taking your medication a few hours apart from consuming it isn’t long enough.
Why should you avoid grapefruit juice while taking verapamil?
Grapefruit juice can
increase the blood levels and effects of verapamil
. Contact your doctor if you experience sudden, unexplained weight gain; swelling of the hands, ankles, or feet; chest pain; or difficulty breathing.
Can you eat grapefruit when on high blood pressure medication?
Most types of blood pressure
medicines are not affected by grapefruit
.
Does grapefruit make you poop?
Citrus fruits like oranges, grapefruits, and mandarins are
high in fiber
and contain several compounds that can reduce constipation, including pectin and naringenin.
Why can’t you have grapefruit with blood pressure medicine?
They’re used as part of the treatment of conditions such as high blood pressure (hypertension) and coronary heart disease. Grapefruit juice interacts with some calcium channel blockers and increases the level of the medicine in your blood.
