By: Karl Neuman, MD

Are you familiar with the harmful effects that may result from medications you give your children? That when you give more than one medication, the two may interact and cause adverse reactions not caused by one alone? That travel-related factors can cause additional interactions?

Reactions to medications are common. Each year, more than half a million U.S. children have medication-related adverse reactions, some serious. Among children, those younger than 5 years are most affected; they metabolize certain substances poorly, allowing undesirable concentrations to accumulate.

Food, food supplements and vitamins can interact with medications. Travel often means new and exotic foods, or familiar foods with different ingredients. Some foods combine with medications, neutralizing them; hence the warnings that certain substances should be taken on empty stomachs. Read drug inserts. Vitamins, food supplements, herbal medications and items marked “natural” or “organic” are often erroneously considered to be benign. Not so. These too can affect medications.

Environmental factors affect medications. Expiration dates on medications are based on proper storage at room temperatures and away from excessive heat, cold, sun and humidity. Exposure to these factors “shortens” expiration dates, and sometimes, in a matter of days, can decompose them chemically into harmful substances. Certain antibiotics and antihistamines, for example, increase the effect of the sun, worsening sunburns.

Travel-related medications can interact with medications. Dramamine (Dimenhydrinate) is commonly used to prevent and treat motion sickness-related nausea, vomiting and dizziness. One website,, lists 414 items that this drug can interact with: 16 major interactions, 390 moderate, and 8 minor. Dimenhydrinate requires no prescription.  Over-the-counter substances are almost as likely to cause adverse interactions as those requiring prescriptions.  

Illness can affect the way medications perform. Intestinal upsets prevents certain medications from being properly absorbed.  Dehydration (from excessive heat) increases the concentration of substances in the body, producing symptoms resembling overdosesTaking anantacid decreases stomach acidity. This acidity is important to destroy diarrhea-causing microorganisms sometimes found in foods, especially in developing countries. Antacids allow microorganisms to multiply more rapidly, sometimes resulting in illness.

Heat may compromise the stability of capsules, tablets and powders.  Prolonged temperatures over 86 degrees F (30 degrees C) can dry out capsules, causing them to become brittle from heat and affecting how well the substance is absorbed from the intestines. Heat can cause antibiotics to lose their potency or make cortisone creams useless. But damage is difficult to detect. Clues include changes in color or consistency, odors and items sticking together. Often decisions on spoilage must be made on the basis of how items were stored.

Most items marked “refrigerate” will maintain potency in a cool room overnight. While traveling, flight attendants usually will store medications in refrigerators if there is room. Cruise ships store medications; some provide refrigerators for staterooms. Battery-operated cooling travel bags are available at travel supply stores. Check the web. 

Humidity adversely affects quickly-dissolving tablets. Many medications for children come in this form. Excess humidity may also have an adverse effect on capsules and give false readings on urine and blood test strips. (At home, humidity makes bathrooms poor choices for storing medications. Store elsewhere.)

Medications may lose their effectiveness if they freeze. This is true for liquids, especially suspensions (items that require shaking before use). Insulin degrades if frozen or kept for prolonged periods in a very hot environment. Unopened bottles of insulin are best kept in the refrigerator. Open bottles can be kept at room temperature.

Pharmacists tend to be your best sources for information. They can access websites which track most known drugs including their side effects, interactions and stability in different environments. And pharmacists can interpret the data for you. When possible, use the same pharmacy for all your family’s purchases enabling them to crosscheck your prescriptions on their computers. Tell them about your OTC purchases and your travel plans. Most large pharmacy chains have websites that you can check yourself. Or check specific medications on the web; most manufacturers have detailed information about their products. Make sure that you check recommendations for children.

Consider medications when children display unusual symptoms.  Symptoms may appear immediately or days later. The most common symptoms include changes in behavior, skin manifestations and gastrointestinal upsets. Medications children take for hyperactivity and attention deficit conditions are prone to drug interactions. Consult your pediatrician regarding what to do if you must discontinue medications. Some should not be stopped abruptly. 

For more information about keeping kids healthy and safe for travel and outdoor activities, please go to