If you eat a healthy diet, grapefruit is certainly part of your fruit basket. Just the bitter-sweet taste makes the grapefruit so refreshing. The fruit originally comes from the Caribbean from the beautiful island of Barbados.
Nowadays you can buy the yellow fruit in supermarkets all over the world. Grapefruit is a valuable fruit. In fact, a single fruit provides 130% of the daily requirement of vitamin C and 35% of that of vitamin A. However, you should be careful when taking medications at the same time.
Grapefruit blocks the breakdown of certain drugs
In addition to vitamins, grapefruit also contains the active ingredients naringin and bergamottin. Consequently, the ingestion of grapefruit interferes with the cytochrome P450 metabolism of your liver, the most important degradation system for drugs. The cytochrome P450 system metabolizes chemical substances for you through a total of 57 subsystems called CYPs.
Naringin inhibits so in liver metabolism the enzyme CYP3A4. Both naringin and bergamottin block the enzyme CYP1A2. Drugs, which are therefore normally broken down via these pathways, are now blocked by the grapefruit and can thus have an enhanced effect. Consequently, more side effects can also occur via an effect amplification.
Just 200 ml of grapefruit juice can be enough to cause a toxic effect of drugs. Even if it's been 3 days since you've had enough grapefruit, then you may be experiencing a side effect. Side effects of grapefruit are strongest if you take it 4 hours before taking the medicine. The half-life, d.h. the time until 50% of the side effect has weakened again is about. 24 hours.
CYP1A2 – effect of coffee enhanced by grapefruit
Examples of substances that are processed via CYP1A2 are numerous antidepressants such as imipramine and duolexitin. Furthermore CYP1A2 also builds melatonin. caffeine via this pathway. Paracetamol, the popular drug for fever reduction and pain relief, also experiences an increase in effect from grapefruit.
CYP3A4 – grapefruit increases side effect in ca. 50% of all medications
Via the cytochrome CYP3A4, ca. 50% of all drugs degraded. Consequently, if you are taking medication, then this is a particularly important switch point. Your body processes z.B. almost all statins for cholesterol reduction via CYP3A4. The calcium antagonists used to lower blood prere, amlodipine and lercanidipine, are also broken down here. Beta-blockers can be so potent in their effect that the heart rate drops critically.
The hormones testosterone and estrogen can have a stronger effect on you, which can be associated with disturbances in your state of well-being. Also many antidepressants like Sertalin and Citalopram are strengthened in your effect by the consumption of Grapefruit.
Of particular importance here are drugs that you only take for a short time, z.B. Antibiotics such as clarithromycin or oral antifungal agents. Side effects may also occur if z.B. Clarithromycin can cause severe arrhythmias by prolonging the QT time in the ECG.
Drugs and grapefruit – get informed
In short, should you be a fan of grapefruit and take medication at the same time, you need to check it out. Incidentally, other citrus fruits, such as z.B.