Medical treatments can affect the way children digest and absorb food. By the same token, what children eat can influence the effects that medications have on the body. For example, griseofulvin, an antifungal medication, needs to be taken with a fatty meal to be absorbed properly. Iron supplements for anemia are best taken with a mild acid like orange juice; if taken with milk they may not be well absorbed. Medications affect nutrition in 4 main areas—they can stimulate or suppress the appetite; they can alter the amount of nutrients absorbed and the rate of absorption; they affect the way the body breaks down and uses up nutrients; and finally, they can slow down or speed up the rate at which food passes through the digestive tract.
Always ask your pediatrician, pharmacist, and other specialists involved in your child’s medical care to explain whether medication should be taken with meals or on an empty stomach. Several antibiotics can cause stomach pain or upset unless taken with food. Also find out whether taking medication with a specific food, such as a glass of milk or grapefruit juice, can make the treatment more or less effective, and ask what foods, if any, should be avoided during treatment.
There are thousands of possible drug-food interactions. The following list represents commonly used medications and foods, and guidelines for preventing such interactions or keeping the effects to a minimum. Be sure to check every prescription with the pharmacist and read the package insert.
Commonly Used Medications and Foods: Guidelines to Prevent Interactions
| Medications | Interactions With Nutrients | Dietary Guidelines |
| Antacids | ||
| Nonprescription indigestion remedies | Foods lessen effects. | Take 1 hour after eating. |
| Antibiotics | ||
| In general | Reduce intestinal production of biotin (a B vitamin), pantothenic acid (vitamin B5), and vitamin K; can speed up passage of food through intestine, decreasing availability for absorption. | Eat a well-balanced diet, including plenty of vegetables, grains, and cereals, to ensure adequate intake of all vitamins. |
| Amoxicillin | Food slows absorption but does not alter dose effect. | None needed. |
| Erythromycin stearatePenicillin | Food decreases absorption. | Take 1 hour before or 2 hours after meals. |
| ClarithromycinErythromycin estolate/succinate | Food improves absorption; fruit juice or carbonated beverages interfere with absorption. | Take with meals. |
| Tetracycline | Binds calcium and iron so that neither antibiotic nor mineral can be absorbed. | Take 2 hours before or after meals and other medications such as iron supplements or calcium-based antacids. |
| Iron Supplements | ||
| Various brands in liquid or tablet form | Milk may interfere with absorption. | Should be taken with water or slightly acidic drinks like fruit juice to improve absorption. |
| Antifungal | ||
| Griseofulvin | Can interfere with effectiveness of birth control pills. | Take with fatty meal. |
| Anticonvulsant/Antiepileptic Medications | ||
| PhenobarbitalPhenytoinPrimidone | Interfere with vitamin D metabolism and thus with calcium absorption; also alter absorption of folic acid. | A good intake of vitamin D (found in fortified milk, egg yolks, oily fish, sunlight), calcium (dairy foods, leafy greens, broccoli, canned fish with bones), and folic acid (fresh fruits, vegetables, grains) should offset medication effects; ask your pediatrician about vitamin D and calcium supplements if your child is on long-term epilepsy treatment; folic acid supplements should not be used because overly high blood levels may decrease anticonvulsant efficacy. |
| Phenytoin | Better absorbed with food or milk. | Take with a meal or a glass of milk. |
| Thyroid Medications | ||
| Levothyroxine | Take on an empty stomach. | |
| Nonsteroidal Anti-inflammatory Medications | ||
| Aspirin (acetylsalicylic acid) | Interferes with storage of vitamin C; may cause iron loss through bleeding in digestive tract. | Do not give aspirin to children unless your pediatrician specifically prescribes it because it has been associated with Reye syndrome, a rare but serious disease affecting the brain and liver following viral infections; use acetaminophen or ibuprofen. |
| Antituberculosis Medications | ||
| Isoniazid | Interferes with vitamin B6 (pyridoxine) metabolism. | Eat a well-balanced diet, including sources of vitamin B6 such as grains, spinach, sweet and white potatoes, bananas, watermelon, and prunes. |
| Corticosteroids | ||
| PrednisoneHydrocortisone | May promote excretion of potassium and calcium. | Reduce salt intake; eat foods high in potassium (fresh fruits and vegetables) and calcium (low-fat dairy foods) to counter loss of these minerals; take with food to lessen stomach upset. |
| Laxatives | ||
| Mineral Oil | Interferes with the absorption of fat-soluble vitamins in the first part of the intestine. | Provide a diet rich in vegetables and fruits for fiber and encourage your child to drink plenty of water; if constipation is a problem, ask your pediatrician’s advice; when mineral oil is prescribed, it should be given at bedtime, after most of the day’s food has passed through the first part of the intestine. |
| Oral Contraceptives | ||
| Various brands | Alter blood cholesterol levels; increase need for folic acid and vitamin B6. | Use another form of contraception if there is a family history of high blood cholesterol or heart disease; consume plenty of fresh fruits and vegetables, grains and cereals, potatoes, and other sources of folic acid and vitamin B6; take with food to prevent nausea; antibiotics may decrease the effectiveness of oral contraceptives. |