Food can affect some medicines. Therefore often your medicine
label may note "take with food", "take on an empty stomach" or "take
half an hour before food". For many medicines that you take every day
it is best to take them at the same time in relation to food every
Common instructions about medicines and foods and usual
explanations are as follows:
Take with food.
- In most cases the medicine can be taken during the meal or
immediately after the meal.
- There may be two reasons for this instruction, either:
- The medicine can cause a stomach upset if you take it without
food (e.g. doxycycline, Augmentin), or
- Food will make the medicine be absorbed better into the body
Take after food.
This may be for the same reasons as take with food. In the case of
Gaviscon, it is used after food so that it works better to stop the
food coming up from the stomach into the oesophagus (gullet).
Take on an empty stomach.
- In most cases the medicine should be taken at least two hours
after the last time you ate and at least one hour before you are
going to eat again.
- Examples include flucloxacillin, and antibiotic that doesn't
work nearly as well if you have it with food, and etidronate
- This instruction is because the medicine is not absorbed as
well by the body if you have much food in your stomach. In some
cases the medicine may bind with something in the food. In other
cases there is a special coating (enteric coating) on the tablet
that does not dissolve until it gets into the intestine, so if you
take the medicine with a big meal it can take many hours to start
working (e.g. anti-inflammatories with an enteric coating).
- Medicines generally work faster if taken on an empty stomach,
so some pain relievers may be recommended to be taken before
Do not take grapefruit or grapefruit juice while taking this
- In the last couple of years grapefruit have been found to
alter the levels of some medicines in the body. In some cases the
amount of the medicine in the blood can be increased by as much as
16 times the usual amount. So, if this instruction is on the label
of your medicine you are best to avoid grapefruit and grapefruit
- Enzymes in the wall of the gut change some medicines on the
way through into the bloodstream, making them less active.
Grapefruit juice blocks these enzymes so medicines that would
normally be changed instead arrive intact in the bloodstream in
greater amounts than expected.
Avoid certain foods with this medicine.
Monoamine oxidase inhibitors such as tranylcypromine (Parnate) or
phenelzine (Nardil) have special instructions with respect to foods.
Many foods need to be avoided including cheese, sour cream, yeast and
meat extracts, liver, sherry, beer (even non-alcoholic), red wine,
avocados, chocolate, soy beans, broad bean pods, meals prepared with
tenderisers, pickled fish, canned figs. Your pharmacist or doctor
will be able to give you a more complete list.
Common medicines taken with food
Anti-diabetics such as glibenclamide and metformin
Anti-inflammatories or NSAIDs (e.g. Voltaren, Naprosyn), unless
enteric coated, or a quick effect is required.
Steroids e.g. prednisone, prednisolone, hydrocortisone
Augmentin (amoxicillin + clavulanic acid)
Aspirin in high doses
Epilim (sodium valproate)
EES (erythromycin ethyl succinate)
Slow K (potassium)
Common medicines taken on an empty stomach
ERA (erythromycin stearate)
ERYC (erythromycin base)
Examples of medicines that don't mix well with grapefruit
Note: This list does not include all medicines, and in some
cases recommendations may differ country to country. Follow the
instructions of your pharmacist or doctor.