Grapefruit, also known as “grapefruit”, is a healthy and nutritious treat for both grapefruit juice and grapefruit, as it is rich in vitamin C and potassium. As the long summer is coming to an end, grapefruit is gradually entering the fruit basket of the public. However, not everyone is a good candidate for grapefruit and grapefruit juice, which can affect the metabolism of many types of medications, especially if you have high blood pressure or an irregular heart rate. Recently, the U.S. Food and Drug Administration (FDA) updated its warnings about grapefruit in relation to medications. Here are some examples of the types of drugs that can cause problems with grapefruit juice: 1) some statins to lower cholesterol, such as simvastatin and atorvastatin; 2) some drugs for high blood pressure, such as nifedipine; 3) some organ transplant rejection drugs, such as cyclosporine; 4) some anti-anxiety drugs, such as buspirone; 5) some corticosteroids for Crohn’s disease or ulcerative colitis, such as budesonide 6. some drugs for abnormal heart rhythm, such as amiodarone; 7. some antihistamines, such as fexofenadine. Grapefruit juice not only affects the above-mentioned types of drugs, in addition, the amount and concentration of grapefruit juice consumed, different types of drugs, also have different effects on drug interactions. Patients can ask their physician or pharmacist and read the instructions for prescription or over-the-counter medications in detail before taking the medication in order to understand how the specific medication may be affected and whether similar citrus fruits may have similar effects. How does grapefruit juice affect drug metabolism? When drugs are swallowed, they may be broken down (metabolized) by enzymes or absorbed in the small intestine through transporter proteins. Grapefruit juice can cause changes in these enzymes and transporter proteins, resulting in too much or too little drug concentration in the body. Some drugs, such as bupropion, which relieves anxiety, are broken down by enzymes. Grapefruit juice blocks the action of these enzymes, increasing the amount of the drug in the body and possibly causing more side effects. Other drugs, such as fexofenadine, which is used to treat allergies, are transferred into human cells by transporter proteins. Grapefruit juice prevents the transporters from acting, decreasing the amount of drug in the body and possibly causing the drug to not work. What are the drugs in psychiatry that are not suitable to be taken with grapefruit juice? Alprazolam, amitriptyline, aripiprazole, buspirone, carbamazepine, citalopram, clomipramine, clozapine, diazepam, eszopiclone, zopiclone, fluoxetine, haloperidol, risperidone, sertraline, trazodone, nimodipine, quetiapine, zolpidem. Studies have been conducted to show that grapefruit juice interacts with hundreds of drugs. Only some of the psychiatric drugs that are mainly metabolized by CYP3A4 are listed here. The proportion of each metabolic pathway varies for each drug, and the level of CYP3A4 enzyme varies from person to person, so please refer to the drug instructions when using the drug.