the medication that you are used to taking always act the same? Not necessarily, depending on the food, other medications or drinks you drink. This is what doctors call drug interactions. More precisely, an interaction is likely to “cause or exacerbate undesirable effects“or”lead, by reduction of the activity, to a lower effectiveness of the treatments“, according to the National Agency for the Safety of Medicines and Health Products (ANSM). The agency distinguishes four levels of interaction:
- the contraindication, which is absolute and must not be violated,
- the association not recommended which requires close monitoring of the patient,
- precaution for use,
- the interaction to be taken into account, which must be assessed on a case-by-case basis by the physician.
While drugs can interact with each other, other substances or conditions can affect how well a treatment works.
Grapefruit and green tea compete with drugs
Among the foods that disrupt the action of drugs, the ANSM identifies the grapefruit, whether consumed as a fruit or juice. It does not decrease the effectiveness of drugs but may increase their side effects. Indeed, grapefruit contains specific molecules, furanocoumarins, which block an enzyme essential for the body to assimilate certain drug molecules. This is for example the case of drugs against cholesterol, immunosuppressants or even certain antidepressants, according to the ANSM. What about the interaction between grapefruit and contraceptive pill, often singled out? Accused of increasing the risk of phlebitis, grapefruit is often warned for women taking oral hormonal contraception. However, the evidence for this interaction is weak and the ANSM currently considers “as improbable the role of grapefruit in the occurrence of phlebitis“.
Another problem drink, yet a source of multiple virtues: green tea. On the one hand, the tannins it contains prevent the absorption of iron, rendering iron supplements taken by people suffering from iron deficiency ineffective. On the other hand, tea is rich in vitamin K, a clotting agent. Its excessive consumption can therefore compete with anticoagulant treatments.
Food supplements and herbal medicine
Some food supplementsor some plants used in herbal medicinemay interact with drugs. This is for example the case of St. John’s Wort, often used for depressive symptoms. It activates enzymes in the liver which will decrease the absorption rates of drugs, and therefore their effectiveness.
Licorice, used in turn against coughs or against digestive disorders, changes blood pressure. It will therefore interact directly with antihypertensive drugs (againsthypertension).
Another plant to watch out for: Ginkgo biloba, popular with people who want to improve their cognitive functions, may increase the effect of certain antidepressants and certain antipsychotics and, on the contrary, decrease that of antiepileptics.
Without forgetting the ginger, the tuber of which is used against nausea (motion sicknessWhere nausea during pregnancy for example) which interferes with the action of anticoagulants and antidiabetics. In the first case, it will increase the risk of bleeding, and in the second, it will increase the risk ofhypoglycemia.
Last example of interaction: taurine, a food supplement that athletes are fond of to boost their shape. As it lowers blood pressure, it directly interferes with blood pressure medications.
Climatic conditions and medication: beware of heat waves and cold waves
Did you know that the effect of a medicine will not be the same depending on whether it is very hot or very cold? Indeed, the body reacts differently in the event of heat wave or extreme cold and the medicinal substances which it receives will not then have the same effectiveness. In hot weather, certain medications can make a syndrome worse. dehydration or one heatstroke, or see their effects amplified if the body is dehydrated. Conversely, when it is very cold, certain drugs can cause or worsen a hypothermia. This is the case with neuroleptics, benzodiazepines or certain antihypertensives.
The particular case of homeopathy interactions
If you are a fan of homeopathic small granules, be careful not to take them at any time of the day. As the absorption of their active ingredients takes place via the small vessels located under the tongue and in the lining of the mouth, the astringent foods that constrict these vessels will decrease the effectiveness of thehomeopathy. This is the case with coffee, tea, alcohol, mint (including that contained in toothpaste) and tobacco. This is why it is often advisable to observe an interval of half an hour between taking granules and consuming these substances.
Sources:
National Agency for Medicines and Health Products Safety (ANSM)
Navarette Sandra, Saussays Charline. Interactions between plants and drugs. Pharmaceutical sciences. 2011
>> To read also:
Homeopathy and medicines do they mix well?
Can we combine different remedies without a prescription?
Medicines: 5 rules to reduce the risk of side effects
