Grapefruit juice inhibits the metabolism of the enzyme CYP3A4.
Grapefruit seeds contain components of furanocoumarin compounds that inhibit the activity of the drug metabolizing enzyme CYP3A4 in the human gut. Whereas the CYP3A4 enzyme is found mainly in the small intestine and liver, it inactivates many drugs and may also increase the activity of some drugs.
Therefore, grapefruit juice and drugs taken at the same time may affect the activity of CYP3A4 enzyme, thus affecting the effect of oral medication, but this needs to have a certain premise, the need to furanocoumarins to a certain level of content to be able to cause a significant response, a small amount of grapefruit juice will not have too much impact on the metabolism of drugs.
However, in daily life, try to avoid drugs and grapefruit juice with food, such as statins, antihypertensive drugs nifedipine, sedative sleeping drug midazolam, immunosuppressant cyclosporine, epilepsy drugs carbamazepine, and so on. In case of discomfort, medical consultation is recommended.