In America, for as long as I remember grapefruit juice interactions are both listed on the bottle and on the pamphlet you receive every single time you get a prescription (renewed or new).
We can't put billboards up for everything. It is your health, and therefore your responsibility, to read the provided literature and raise any questions to your doctor. It's not obscured or hidden knowledge. In fact, it's usually one of the first things mentioned in big, bold text. In addition every pharmacy I've been to offers consulting on medications for free and in general doctors will always go over major interactions with medication (though I've had less luck with this).
We can't put billboards up for everything. It is your health, and therefore your responsibility, to read the provided literature and raise any questions to your doctor. It's not obscured or hidden knowledge. In fact, it's usually one of the first things mentioned in big, bold text. In addition every pharmacy I've been to offers consulting on medications for free and in general doctors will always go over major interactions with medication (though I've had less luck with this).