Jenifer Theresal J
Senior Dietician, Kauvery Hospital, Tennur, Trichy, India
*Correspondence: dietary.ktn@kauvery.in
Nutrition and drug interaction
Abstract
The effect of drug on a person may be different than expected because that drug interacts with another drug the person is taking (drug-drug interaction), food, beverages, dietary supplements the person is consuming (drug-nutrient/food interaction) or another disease the person has (drug-disease interaction). Major side-effects of some diet (food) on drugs include alteration in absorption by fatty, high protein and fiber diets.
Background
Medicines can treat and cure many health problems. However, they must be taken properly to ensure that they are safe and effective. Medications should be extremely specific in their effects, have the same predictable effect for all patients, never be affected by concomitant food or other medications, exhibit linear potency, be totally non-toxic in any dosage and require only a single dose to effect a permanent cure. However, this ideal drug is still to be discovered. Interactions between food and drugs may inadvertently reduce or increase the drug effect. Some commonly used herbs, fruits, as well as alcohol, may cause failure of the therapy up to the point of serious alterations of the patient’s health.
Antibiotics and Dairy Products
Dairy products such as milk, yogurt, and cheese can delay or prevent the absorption of antibiotics such as tetracyclines and ciprofloxacin (Cipro). This occurs because the calcium in such foods binds to the antibiotics in the stomach and upper small intestine to form an insoluble compound.
To avoid problems, it is recommended to take an antibiotic one hour before or two hours after a meal.
However, there’s no need to avoid milk and dairy with all antibiotics.
For example, it’s recommended that metronidazole (Flagyl) should be taken with water or milk to prevent stomach upset.
Digoxin, High-Fiber Diets, and Herbs
Digoxin (Digitalis, Digitek, Lanoxin) is used to strengthen the contraction of the heart muscle, slow the heart rate, and promote the elimination of fluid from body tissues.
Dietary fiber, specifically insoluble fiber such as wheat bran, can slow down the absorption of digoxin and lessen its effectiveness. To prevent this, elders should take digoxin at least one hour before or two hours after eating a meal.
Herb use can also affect digoxin. For example, ginseng can elevate blood levels of digoxin by as much as 75%, while St. John’s Wort decreases blood levels of this drug by 25%.
It’s important for the patient to recognize signs of digoxin toxicity. These include a yellow tint to vision and the appearance of halos around objects, as well as weakness, confusion, dizziness, and nausea and vomiting.
Anti-thyroid Drugs and Iodine-Rich Foods
Anti-thyroid drugs are compounds that interfere with the body’s production of thyroid hormones, thereby reducing the symptoms of hyperthyroidism. According to a broad body of research, Americans’ high-iodine diets account for the lower remission rate of hyperthyroidism in those who are prescribed anti-thyroid drugs.
Anti-thyroid drugs work by preventing iodine absorption in the stomach. A high-iodine diet requires higher doses of anti-thyroid drugs. The higher the dose of anti-thyroid drugs, the greater the incidence of side effects that include rashes, hives, and liver disease.
The richest dietary sources of iodine are seafood and seaweed. Iodine is also found in iodized salt and to a lesser extent in eggs, meat, and dairy products.
Anti-tubercular Drugs
Anti-tubercular drugs like isoniazid have interaction substances that contain tyramine and histamine. High-fat meals decrease the serum concentration of cycloserine, a bacteriostatic anti-tubercular drug and result in incomplete eradication of bacteria.
Some significant Food-Drug Interactions
| Drugs | Food | Drug-Food Interaction |
| WARFARIN | High-protein diet | raise serum albumin levels, and decrease in international normalized ratio (INR) |
| Vegetables containing vitamin k | interferes with the effectiveness and safety of warfarin therapy. | |
| Charbroiled foods | decrease warfarin activity | |
| Cooked onions | increase warfarin activity | |
| Cranberry juice | elevates INR without bleeding in elderly patient | |
| Leafy green vegetables | Reduce efficacy of anticoagulation, thromboembolic complications may develop | |
| Monoamine Oxidases | Tyramine-containing food | hypertensive crisis |
| Propranolol | Rich protein food | serum level may be increased |
| Celiprolol | Orange juice | the intestinal absorption is inhibited |
| ACES Inhibitors | Empty stomach | absorption is increased |
| CA2 Channel | Grape fruit juice | increases the bio availability |
| Antibiotics | with milk products | that complex with some antibiotics and prevent their absorption. reduced bio availability |
| Acetaminophen | Pectin | delays its absorption and onset |
| Theophyline | High-fat meal and grape fruit juice | increase bio availability |
| Caffeine | increases the risk of drug toxicity | |
| Esomeprazole | High-fat meal | Bioavailability was reduced |
| Cimetidine, rupatadine | with food (any type) | increase bioavailability |
| Isoniazide | Plants, medicinal herbs, oleanolic acid | exerts synergistic effect |
| Cycloserine | High-fat meals | decrease the serum concentration |
| Acarbose | at the start of each meal | maximum effectiveness |
| Mercaptopurine | Cow’s milk | reduce bioavailability |
| Tamoxifen | Sesame seeds | negatively interferes with tamoxifen in inducing regression of established mcf-7 tumor size but beneficially interacts with tamoxifen on bone in ovariectomized athymic mice |
| Levothyroxine | Grapefruit juice | delay the absorption |
Reference
Frankel EH. Basic Concepts. In: Hand book of food-drug Interactions, McCabe BJ, Frankel EH., Wolfe JJ (Eds.) pp. 2, CRC Press, Boca Raton, 2003.
Ayo JA, et al. Food and drug interactions: its side effects. Nutr Food Sci. 2005;35(4):243-252.
Jenifer Theresal J
Senior Dietician
