Dr. Maria Kosteliova points out that taking medications with certain foods and drinks directly affects their effectiveness and reduces their therapeutic effect.
She says: “It is preferable to take pills with water, because tea and coffee may affect the effectiveness of some medications, as these drinks contain tannins, which are astringent substances that can bind to some medications, such as those containing iron, thus reducing their effectiveness. Therefore, it is best to postpone taking medications in the morning for at least 1-2 hours after drinking coffee or tea.”
Antibiotics should also be avoided with dairy products, as these can interfere with drug absorption and form insoluble compounds. Magnesium and iron supplements may have a similar effect. Furthermore, vitamin C should not be taken with birth control pills.
"This happens because vitamin C competes with estradiol for receptors in the intestines, increasing its concentration," she says.
Costellova urges people to separate the intake of antibiotics from medications that reduce stomach acid, noting that doing so will reduce the effectiveness of the medications.
She says: "Substances found in plant-based foods, such as grapefruit juice, may slow down the conversion of many drugs into metabolites in the liver. This leads to higher levels of some drugs, such as statins, which may cause unwanted side effects."
She also emphasized the importance of avoiding foods rich in vitamin K (leafy green vegetables) when taking medications that affect blood clotting, as it reduces the effectiveness of the medication and increases the risk of blood clots.
She says: "When taking antidepressants, you should avoid foods such as aged cheeses, smoked meats and fermented foods, as they may lead to high blood pressure and headaches."
Dr. Alexei Panov points out that taking medications with carbonated drinks or other non-alcoholic beverages can affect their effectiveness and may even cause side effects. For example, sweetened carbonated drinks contain carbon dioxide, sucrose, fructose, flavorings, and dietary acids, which temporarily alter stomach pH and may cause rapid gas production. They may also accelerate or slow the dissolution of tablet coatings.
