Several drugs when given orally can interact with food consumed by the patients. Table 1 shows the medications which should be taken on an empty stomach.
Table 1: Medications which should be taken on an EMPTY STOMACH
Drug | Food interactions and effect |
Ampicillin | Reduced absorption |
Alendronate | Decreased bioavailability |
Azithromycin | Reduced absorption |
Bisacodyl | Dissolves enteric coating |
Didanosine | Decreased absorption |
Indinavir | Reduced absorption with fat, proteins |
Isoniazid | Reduced absorption |
Isosorbide dinitrate | Delayed absorption |
Levothyroxine | Reduced absorption; anionic exchange resins reduce absorption |
Melphalan | Reduced absorption |
Methotrexate | Reduced absorption |
Mycophenolate | Enhanced absorption |
Omeprazole | Delayed absorption |
Oxytetracycline | Reduced absorption when taken with dairy products. |
Rifampin | Delayed absorption |
Roxithromycin | Reduced absorption |
Sulfadiazine | Formation of crystalluria on consumption with vitamin C or acidifying agents |
Tacrolimus | Reduced absorption |
Tetracycline | Reduced absorption, especially when taken with antacids or dairy products |
Thyroid | Reduced absorption |
Typhoid vaccine (oral) | Reduced absorption |
Zidovudine | Enhanced absorption |
Food can also impact the effectiveness of a drug due to the way it is consumed. Generally, medicine is to be taken almost at the same time the food is eaten. This is because the medicine may upset the stomach, if the stomach is empty. Certain medications are recommended to be taken with food (Table 2).
Table 2: Medications which should be taken WITH FOOD
Drug | Food interactions and effect |
Acetylsalicylic Acid | Reduced side effects. |
Allopurinol | Reduced side effects; reduced clearance of active metabolite with protein-poor diet |
Amiodarone | Enhances both the rate and extent of absorption |
Amoxycillin/clavulanic acid | Reduced side effects |
Azathioprine | Reduced side effects |
Baclofen | Reduced side effects |
Bromocriptine | Reduced side effects |
Carbamazepine | Increased absorption |
Cefuroxime | Increased absorption |
Chloroquine | Reduced side effects |
Clofazimine | Increased drug absorption |
Conjugated estrogens | Reduced side effects |
Diclofenac | Reduced peak concentration but not extent of absorption; reduced side effects |
Doxycycline | Reduced side effects; reduced absorption with milk |
Ethinyl estradiol | Reduced side effects |
Ferrous salts | Take between meals, if gastrointestinal upset occurs take with food |
Griseofulvin | Increased rate or extent of absorption with fats; reduced side effects |
Hydroxychloroquine | Reduced bowel side effects; masks the bitter taste of drug |
Hydrocortisone | Slows rate of absorption; reduced peak levels; reduced side effects |
Ibuprofen | Reduced side effects |
Iron preparations | See iron salts |
Levocetirizine | May be taken with or without food |
Lithium | Reduced side effects |
Mebendazole | Increased absorption |
Methadone | Reduced side effects |
Methylprednisolone | Reduced side effects |
Metronidazole | Reduced side effects |
Mexiletine | Reduced side effects; slows rate of absorption; reduces rate of caffeine clearance |
Morphine | Increased absorption |
Nelfinavir | Greatly increases absorption and AUC |
Niacin | Reduced absorption; decreases side effects |
Nitrofurantoin | Increased absorption |
Pioglitazone | Food slightly delays absorption rate but extent of absorption is not affected |
Potassium salts | Reduced side effects |
Prednisolone | Reduced side effects |
Prednisone | Reduced stomach irritation |
Procainamide | Reduced side effects; increased absorption with fat |
Propranolol | Slows rate but increases extent of absorption |
Quinine | Reduced side effects |
Ritonavir | Increased absorption |
Salsalate | Reduced stomach irritation |
Saquinavir | Increased absorption |
Sodium chloride | Reduced side effects |
Spironolactone | Increased absorption; reduced side effects |
Sulfasalazine | Reduced side effects |
Sodium valproate | Reduced side effects |
Table 3: Selected herbal or food products resulting in adverse effects
Herb/Food | Drug | Adverse Effects/Reported Drug Interactions/ Remark |
---|---|---|
Licorice | Digoxin Spironolactone | Elevates serum digoxin levels 4-fold, arrhythmias Hypokalemia and muscle weakness |
Foods high in vitamin K (broccoli, sprouts, turnip greens, spinach, cauliflower, legumes, mayonnaise, soybean oils and fish | Anticoagulants (warfarin) | Such foods may reduce the effectiveness of anticoagulants, increasing the risk of clotting. Intake of such foods should be limited, and the amount consumed daily should remain constant |
Foods high in sodium (like licorice, processed meats, canned foods) | Amlodipine | Such foods decrease the effectiveness of the drug |
Calcium or foods containing calcium (milk and other dairy products) | Tetracycline | These foods can reduce the absorption of tetracycline, which should be taken 1 h before or 2 h after eating |
Foods high in tyramine, (includes cheese, yoghurt, sour cream, cured meats, liver, dried fish, bananas, yeast extracts, raisins, soya sauce, red wine, certain beers) | MAO - inhibitors (such as phenelzine and tranylcypromine) | Severe headache and a potentially fatal increase in BP (hypertensive crisis) can occur if people taking MAO - inhibitors consume these foods. These foods must be avoided |