Blood pressure medication and grapefruit: Why taking them together can cause a sudden drop in blood pressure and the associated risks.

Never eat this fruit while taking antihypertensive medication:

Once, a patient with long-term hypertension, who had been taking nifedipine controlled-release tablets, came to the clinic complaining of dizziness, nausea, and sweating. His blood pressure was measured at 86/46 mmHg. Neither the patient nor his family understood, as his blood pressure was usually high, reaching 150/90 mmHg even with medication. After a detailed medical history, the doctor discovered that the patient had eaten a fruit—grapefruit—two hours before his appointment. Why would grapefruit rapidly lower blood pressure? Does grapefruit have a blood pressure-lowering effect?

Grapefruit is just a fruit and doesn't lower blood pressure itself. However, grapefruit contains a large amount of furanocoumarins, a substance that can inhibit cytochrome P450 3A4 (CYP3A4), an enzyme that metabolizes drugs in the body. Many clinically important drugs require this enzyme for metabolism. Inhibition of this enzyme slows drug metabolism, amplifying the effect of antihypertensive drugs and causing a rapid drop in blood pressure. This can lead to insufficient organ perfusion, potentially triggering myocardial infarction, cerebral infarction, or even sudden death.

Other studies have found that grapefruit's effect on medication is strongest within 4 hours; if the interval is 10 hours, the effect decreases to 50%; if the interval is more than 24 hours, the effect is only 25%; complete metabolism takes 3 days.

Grapefruit cannot be taken with medication, but can pomelo be taken simultaneously?

Actually, grapefruit and pomelo are two different fruits. Although both belong to the Rutaceae family, their fruits, shapes, and nutritional components differ. Grapefruit is a hybrid variety. Pomelo originated in Southeast Asia and was later introduced to China.

Nutritional differences:

1. Grapefruit has a higher folic acid content, while pomelo has a lower folic acid content.

2. Grapefruit contains naringin, while pomelo does not.

3. Grapefruit contains higher levels of many vitamins and trace elements, such as vitamin C and potassium, than pomelo.

4. Grapefruit contains a large amount of furanocoumarins, while pomelo has a lower furanocoumarin content.

In summary, grapefruit has a high content of furanocoumarins, so it should be avoided when taking certain medications, such as antihypertensive and lipid-lowering drugs. Grapefruit, on the other hand, has a lower furanocoumarin content, and as long as it is not consumed in large quantities, it generally will not have a significant impact. However, Dr. Zhou reminds everyone not to "compete" with grapefruit and pomelo; when taking antihypertensive drugs or some cardiovascular medications, avoid eating these fruits.