We need food to live, but also in case of illness, we must take medication to heal. This union food can cause multiple drug interactions, which in some cases may be beneficial because they decrease or increase the adverse effects of drug efficacy, but in other cases may be undesirable to cause treatment failure. Such interactions can occur with medications prescribed by a doctor or not (antacids, vitamins and iron pills). It is therefore important to tell the patient the correct way to take the drug to achieve the desired therapeutic effect.
1. Definition Grapefruit is one of the foods that interact with some medications.
Food drug interaction we can define as originating in the appearance of a pharmacological effect , toxic or therapeutic treatment of lower intensity or higher than expected, which occurs as a result of the action or presence of food on a drug or vice versa .
Such interactions are not detected as frequently as drug-drug interactions. However, are the most frequently given potential food because the substances that are associated with greater frequency of taking medication.
Therefore, many interactions can occur between foods and drugs, although only a few can be considered clinically relevant and may lead to a decrease in the effectiveness of a treatment or adverse effects. Higher risk situations are those involving drugs with a narrow therapeutic drugs and chronic use.
2. Factors influencing In this type of interaction that interfere with the three agents are present whenever we use a drug, ie the patient, drug and food / nutrient. Therefore the factors that influence food-drug interactions are:
- patient-dependent factors : drug response that may occur will vary depending on: the patient's genetic factors, age, sex, physiological state that is (growth, pregnancy, lactation), pathological condition or deficiency.
- drug-dependent factors : are those given by their own pharmacological characteristics of the drug therapeutic index such as the present or dose-response curve.
- Factors dependent on food : the fat, protein and carbohydrates in the diet and the liquid ingested are the decisive factors in the interactions of foods with medication. There are dietary components that play an important role in the induction of this type of interactions between them may include: foods high in tyramine, sodium and potassium, fiber-rich foods, milk and dairy products, fruit juices with , coffee, etc. .
3. Types of interactions Can be classified by the type of mechanism that explains the interaction:
- Altered pharmacokinetics : food can alter the pharmacokinetics of drugs in different ways, being able to alter their absorption, distribution, metabolism or excretion.
- Modification pharmacodynamics : the food can affect the mechanism of drug action. They come in smaller numbers than the pharmacokinetics, but are higher in the level of severity for the patient.
4. Most important pharmacokinetic interactions between drugs and foods Foods high in fat , reduce the absorption of antiretroviral drugs up to 50% and its effects.
Garlic in large amounts , reduces the bioavailability of antiretroviral drugs by reducing absorption and / or increase their metabolism.
Milk and iron salts , reduce the absorption and effects of fluoroquinolones and bisphosphonates.
Foods rich in protein , reduce the absorption of ulcer (sucralfate) by binding to proteins can cause blockages.
cruciform vegetables such as brussels sprouts, cauliflower, cabbage, broccoli, etc. . : indoles given its content may decrease the effectiveness of oral anticoagulants (warfarin, acenocoumarol) by inducing its hepatic metabolism. Soybeans : increased plasma levels of drugs (haloperidol, NSAIDs, warfarin, etc) and their adverse effects.
Grapefruit juice : increased plasma levels of antagonists, calcium channel blockers, anti-rejection transplant drugs, triazolam, saquinavir, also causing an increase in cardiotoxicity in astemizole, terfenadine, cisapride and pimozide.
5. Most important pharmacodynamic interactions between drugs and foods Cruciferous vegetables such as brussels sprouts, cauliflower, cabbage, broccoli, etc. . : Because of its high content of vitamin K decreases the effectiveness of oral anticoagulants (warfarin, acenocoumarol) to antagonize its effect.
Licorice or extract : the action of licorice mineral corticoids antagonize the antihypertensive effect (thiazide diuretics, beta blockers).
Soybeans : their anti-estrogenic phytoestrogens antagonize the action of the drug.
Garlic in large amounts , potentiates the anticoagulant effect (oral anticoagulant warfarin, acenocoumarol), since garlic has anti-platelet effect.
Foods rich in thiamine (pâtés, herring, cheeses, salami, etc. ). : may cause hypertensive crisis and even as enshrined in the literature have been cases of cerebral hemorrhage with MAOI antidepressants.