tablets

[chazza]

I just got new hay fever tablets and was reading the leaflet.  It says i shouldnt
- take them if i'm allergic to the ingredients
- take them on other medication

and then rather bizarrely it says
"Do not drink grapefruit juice while taking this medication"

why is that?

[kick3m0n]

it's the same for my father in laws blood pressure tablets.  A pharmacist will be able to tell you why....doubtless some bizarre interaction that makes you hayfever tablets lerss effective.

[Clanad]

Take a look here:

http://www.powernetdesign.com/grapefruit/

[chazza]

But why grapefruit juice?  It doesnt say anything about not eating grapefruits!

[Robinia]

Grapefruit can increase (occasionally decrease) the effect of some medications.

Another site here 

[ianess]

Certain acidic juices affect medication in different ways.
I'm on blood pressure tablets and was told to stop taking orange juice with my vodka!!

[Hgrove]

I have come across this before;  apparenty there's a type of antihistamine which supposedly causes heart attacks when taken with grapefruit juice. Sorry I cannot be more precise.