Grapefruit, liquorice and your medicines

When you take a medicine, your body will start to break it down using proteins called enzymes. Different enzymes break down different medicines.

The amount of medicine you take (the dose) is worked out to allow for how long this breakdown takes.

Grapefruit and grapefruit juice stops one of your enzymes from working. This means some medicines will not be broken down. Instead they can build up in your body.

When you have too much of the medicine in your body you are at risk of severe side effects. These could be very dangerous.

If you have been told not to take grapefruit, then you are probably taking one of the medicines that is known to be a problem. If you are not sure, please ask your healthcare team to confirm.

No, the effect of grapefruit on the enzyme can last more than 24 hours. So even if you only take your medicine once a day it is not safe to have grapefruit at the other end of the day.

Grapefruit juice is sometimes an ingredient in other drinks. Always check the ingredients of anything called “citrus” or “tropical”.

If you take ciclosporin avoid:

• pomelo juice
• purple grape juice.

If you take tacrolimus avoid:

• pomelo juice
• pomegranate and pomegranate juice

There is also some evidence that you should avoid the following if you are taking tacrolimus:

• Seville oranges and marmalade (jaffa, or sweet oranges and their juice are fine)
• large amounts of lime juice (a squeeze in cooking or in a drink is fine)
• large amounts of bergamot or dried citrus fruit peel
• large amounts of Earl Grey tea (have no more than 2 cups a day)

Grapefruit affects lots of drugs. This includes some immunosuppressants, statins, blood thinners, and medicines for high blood pressure, or anxiety. People taking different medicines to you might have been given different advice about grapefruit.

If you are not sure if it is safe for you to have grapefruit, you can look at the leaflet in the medicine box. Or ask your pharmacist or doctor.