Many patients ask this question during a home medicines review – and it is surprising how food can change the way a drug works in the body.
Food affects the way that medicines work in the body by changing;
- Absorption or how much and how quickly a drug gets into the body
- Distribution or where the drug goes (into organs, tissues, and cells)
- Metabolism or how drugs are changed as this may increase or decrease the action of a drug
- Clearance or how drugs are removed from the body
Anything that increases the drug’s action in body may cause side effects and or toxicity
For example – The effect of metoprolol on the heart (slows rate) may increase if taken with food – especially if metoprolol was previously taken before food.
Any food that decreases the drug’s action may not treat the illness properly.
For example – Taking digoxin with fibre rich food decreases absorption, undertreating heart failure.
It is possible to eat some foods that interact with your medicines but having a regular and balanced diet becomes more important here.
For example – Patients that take warfarin to prevent blood clots need to avoid too much vitamin k rich foods in their diet. They can eat some vitamin K rich foods like broccoli, kale, spinach, and cabbage but they should eat the same amount regularly each week.
Elderly people are at a greater risk of drug/ food interactions because they take more medicines (polypharmacy) in general.
Grapefruit and grapefruit juice (moderate amounts) can increase the effect of some drugs causing adverse effects – this may include medicines like;
- Verapamil which may cause lightheadedness, sweating, irregular heart beat
- Statins which may cause unusual tiredness, weakness, severe muscle cramp and muscle damage.
- Sertraline which may cause irritability, confusion, and mood changes
Some bone medicines (Alendronate and Risedronate) which help to reduce fractures in elderly patients don’t work as well when taken with food
And antibiotics like ciprofloxacin should be taken one hour before or two hours after dairy foods (and food in general), as this results in less antibiotic in the blood to fight infection.
So, a medication review may help the patient improve their medicine use by finding the right way to take their medicines with food.
This is very important for elderly people living in Aged Care Facilities.
The type of food and timing of meals can make a big difference to the patient’s wellbeing.
In many ways, it is not that surprising – your “good medicine” may just depend on when and what you eat.
Emmanuel Pippos, Consultant Pharmacist