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• Food (herb)-drug interaction


  When a food, or one of its components, interferes with the way a drug is used in the body
• Drug-nutrient interaction

  When a drug affects the use of a nutrient in the body
• Food-drug interactions


  1. Avoid taking food and medication together because the food can make the drug less effective

  2. It may be better to take the drug with food to prevent stomach irritation
• Alcohol usually affects the way most drugs are metabolised
• Drug-nutrient interactions


  1. Some drugs interfere with the absorption of a nutrient

  2. Other drugs affect the body's use and/or excretion of nutrients, especially vitamins and minerals
• If less of a nutrient is available to the body because of these effects, this may lead to a nutrient deficiency
• Drugs can interfere with a person's nutritional status by increasing or decreasing appetite
• Factors affecting interactions


  • Age
  • Gender
  • Medical history
  • Body composition
  • Nutritional status
  • Number of medications used
• Other factors affecting interactions

  • Type of medication
  • Form of drug (pill, liquid, etc.)
  • Dosage
  • Site of absorption (mouth, stomach, intestine)
  • Route of administration (oral, intravenous, etc.)
• How drugs react in the body

  1. Drug dissolves into a useable form in the stomach

  2. Drug is absorbed into the blood and transported to its site of action

  3. Body responds to the drug and the drug performs a function

  4. Drug is excreted from the body either by the kidney, the liver, or both
• Foods can interfere with any stage (i.e. absorption, action, excretion)
• The most common way of interference is with drug absorption, which can make a drug less effective
• Pomegranate juice may also be implicated in drug interactions
• Grapefruit juice is the only citrus juice that contains furanocoumarin
• Grapefruit Juice and Drugs

  1. Don't take medications with grapefruit juice

  2. Drink it at least two hours before/after taking the medication

  
• Analgesics


  • Drugs that relieve pain
  • Often cause stomach irritation, so it's a good idea to take them with food to lower the risk
• Antacids and acid blockers

  • Antacids neutralise stomach acid
  • Acid blockers reduce stomach acid production
  • Long term use may lead to certain nutrient deficiencies, as stomach acid is important for digestion and/or absorption of nutrients, e.g. Vitamin B12
• Gastric cells produce Intrinsic factor which enables Vitamin B12 absorption
• Older people produce less stomach acid, leading to low absorption of Vitamin B12
• Regular use of antacids or acid blockers lowers Vitamin B12 absorption even more, so Vitamin B12 supplements may be needed
• Antibiotics


  • Used to treat bacterial infections
  • Some decrease the synthesis of Vitamin K by the bacteria normally found in our intestines, which is important for normal blood clotting
  • Tetracycline binds to calcium in dairy products, decreasing antibiotic absorption
  • Penicillin and erythromycin are most effective when taken on an empty stomach as they may be partially destroyed by stomach acid when taken with food, but food can reduce stomach irritation
• Antihistamines


  • Used to treat allergies
  • Often cause drowsiness, which is increased by alcohol
  • May also increase appetite, leading to weight gain
• Anti-inflammatory drugs


  • Prescribed for chronic joint pain, headaches, arthritis
  • Long-term use may lead to stomach irritation and ulcers, so should be taken with food
• Blood pressure lowering drugs


  • Can affect body levels of minerals like potassium, calcium, and zinc
  • For diabetics, can cause problems controlling plasma glucose
  • Natural liquorice causes salt and water retention, leading to increased blood pressure
• Diuretics


  • Cause the body to excrete more urine, used to treat high blood pressure and fluid buildup
  • Some increase urine losses of minerals like potassium, magnesium, and calcium, while others limit mineral loss
• Lipid lowering drugs


  • Reduce blood cholesterol levels
  • Medications like cholestyramine may decrease absorption of fat soluble vitamins, Vitamin B12, folic acid, and calcium, requiring supplementation
• MAO inhibitors


  • Decrease the body's use of monoamines, neurotransmitters affecting CNS development
  • Can react with tyramine in aged/fermented foods like aged cheese, causing a dangerous rise in blood pressure
• If the reaction with tyramine is not treated, it can cause death
• Drugs can interfere with a person`s nutritional status by increasing or decreasing appetite.
• Grapefruit Juice*


  Among all fruit juices, grapefruit juice possesses high interaction with almost all types of drugs

  Pomegranate juice may also be implicated in drug interactions

  Grapefruit juice contains a compound called furanocoumarin

  It increases the absorption of some drugs. This can enhance their effects.

  This compound is not found in other citrus juices.
• It’s best to not take medications with grapefruit juice.
• Drink it at least two hours before/after taking the medication.
• Anticoagulants

  Anticoagulants slow the process of blood clotting.

  These drugs, like warfarin (Coumadin), work by interfering with the use of vitamin K in blood clotting.

  People taking anticoagulants should be consistent in the amount of vitamin K they get from foods.

  It’s very important to avoid eating large amounts of foods high in vitamin K.

  Rich sources of vitamin K include liver, and green vegetables such as broccoli, spinach and other leafy greens.
• Anticonvulsants


  Anticonvulsant drugs help control seizures .

  may cause diarrhoea and a decrease in appetite.

  increase the use of vitamin D in the body. This means that less vitamin D is available for important functions such as calcium absorption.

  Vitamin D supplements may be needed.

  Some anticonvulsants also interact with folic acid.

  When drug therapy is started, folic acid levels in the body decrease.

  folic acid supplements affect blood levels of the drug, supplementation must be supervised by a doctor
• Blood Pressure Lowering Drugs

  Antihypertensives are used to control high blood pressure.

  Used widely in developed countries due to the large number of people with obesity.

  They can affect body levels of minerals such as potassium, calcium, and zinc.

  Natural liquorice, found in some imported candies, causes salt and water retention which then lead to an increase in blood pressure
• Cancer Drugs


  Antineoplastic agents are used to treat different forms of cancer.

  Many cause nausea, vomiting, and/or diarrhoea.

  All of these can affect nutrient status.

  Some of these drugs reduce availability of folic acid
• Laxatives


  Excessive use of laxatives can deplete vitamins and minerals needed for normal body function.

  Laxatives also increase fluid losses. This may lead to dehydration.
• Mental Health Drugs


  Some of these drugs increase appetite while others decrease it.

  Either effect can impact weight in a significant way.

  Alcohol can intensify the drowsiness caused by these drugs.

  Some psychotherapeutic drugs are Monoamine Oxidase (MAO) inhibitors.
• MAO Inhibitors


  Some aged and fermented foods are high in tyramine. They should be avoided by people taking MAO inhibitors.

  A few of these foods are: – Aged cheese – Brewer’s yeast, yeast extracts – Chianti wine – Pickled herring – Fava beans