Medicines And Foods - How Do They Interact?

It is a popular rule that abstinence from alcohol is the most reasonable thing when taking medication. Recommended measure for some, but even mandatory for some specific medications.

When we have to take several different medicines at the same time, we usually receive recommendations from the doctor as to which ones should and should not be combined and at what intervals to take them.

But when it comes to nutrition, recommendations are usually limited to fasting or before / after meals. Are there more special cases and can we without feeling through the diet to spoil the treatment plan?

Levels of interaction

The way we eat may affect the therapeutic effect of the drug in the following directions:

• To accelerate and / or enhance its resorption and effect;
• To weaken its resorption and effect;
• To change its action.

Drugs are subject to the laws of physics and chemistry and their resorption through the lining of the gastrointestinal tract depends on the acidity of the environment, the rate of peristalsis and others.

It is the food we eat that determines the level of stomach acidity, the time of gastric emptying, the secretion of digestive juices, the level of blood flow in these organs and the liver, as well as the degree of bile excretion.

Thus, the main level of interaction between food and medicine is that of absorption. First of all, this is dangerous because it can reduce the therapeutic effect and the patient risks not receiving adequate treatment.

There are fewer cases in which the nutrients taken change the effect of the drug and this happens through changes in its metabolism and / or strengthening or weakening of its action.

Which interactions to keep in mind?

• Antibiotics and dairy products

In general, most antibiotics are better absorbed when taken on an empty stomach. There should be a difference of several hours between the intake of tetracycline antibiotics and dairy products rich in calcium , as together they form insoluble complexes that are almost indigestible.

• Acids and bases

The high pH in the stomach (caused by "alkaline" foods or antacids) reduces the absorption of drugs that are weak acids - aspirin, isoniazid and others.

• Antidepressants - "cheese syndrome"

When treated with antidepressants from the group of monoamine oxidase inhibitors (MAOIs) should not take foods rich in tyramine - smoked meats, bananas, soy sauce, tofu, fermented foods and beverages such as cheese, beer, wine). MAO reduce the breakdown of tyramine and it can cause severe , life-threatening hypertensive crises .

• Anticoagulants 

Foods rich in vitamin K - avocado, Brussels sprouts, broccoli, cabbage and more. increase blood clotting and it is reasonable to limit them in patients being treated for it. At the same time, fish oil is a weak anticoagulant, and garlic enhances the antiplatelet effect of aspirin. 

• ACE inhibitors

One of the most prescribed antihypertensive drugs. May cause elevated potassium levels. This is especially dangerous with increased potassium intake, for example in the composition of salt substitutes and puts the patient at risk of cardiac arrhythmia.

• Grapefruit

It blocks certain enzymes in the intestinal mucosa and liver in such a way that it accelerates the absorption and reduces the destruction of certain drugs, which can become a prerequisite for the manifestation of their toxic effects . The main drugs that are affected by this mechanism are statins - lovastatin, as well as diazepam, nifedipine, cordarone and others.

• Which drugs to take with food?

Non-steroidal anti-inflammatory drugs as well as corticosteroids have an irritating effect on the lining of the gastrointestinal tract and are recommended to be taken with food or milk.

The antiepileptic drugs phenytoin and carbamazepine are taken after meals.

Each medicinal product has a leaflet with detailed information, including the interaction of the preparation with food, alcohol and other drugs. The responsibility for your health is first and foremost yours and it deserves a few minutes of careful reading!