The mouth, throat, and intestines are lined with cells that divide rapidly and can be severely damaged by chemotherapy drugs. This damage is more common for children on very intensive protocols and for those having stem cell transplants. The sores that develop in the mouth, throat, and intestines are extremely painful and can prevent eating and drinking. Check your child’s mouth regularly for sores, and if any are present ask the oncologist for advice. Following are some suggestions from parents:

• To prevent infection, the mouth needs to be kept as clean and free of bacteria as possible. After eating, have your child gently brush teeth, gums, and tongue with a soft, clean toothbrush.

We use Biotene® to prevent mouth sores. It is a little minty, foams a bit, and is alcohol-free, so it does not burn. Our nurse practitioner swears by it. She told us that it is the only thing that she has seen that seems to prevent mouth sores. We suspected Nico had sores in his throat after the high-dose methotrexate based on drooling, complaining of pain, and refusing to eat or drink without pain medication, but he never had visible sores in his mouth. We use Biotene® religiously when we are inpatient. We apply it with an oral sponge or an extra soft toothbrush. One warning though, Nico does not enjoy it.

• If your child is old enough, the doctor may recommend a rinse to decrease the amount of bacteria in your child’s mouth, which helps prevent mouth sores.

When David was told to use Peridex®, I asked the doctor if we could substitute 0.63% stannous fluoride rinse. He said yes. As a dentist, I knew Peridex® kills bacteria and lasts up to eight hours, but it tastes terrible and stains teeth. Children do not like using it. The 0.63% stannous fluoride has the same bacteria-killing properties and also lasts up to eight hours, but has a better taste and does not stain as badly. The fluoride also helps prevent cavities and makes the teeth less sensitive. It comes in a variety of flavors like mint, tropical, and cinnamon. It is a prescription drug that a lot of dentists dispense. To prepare, mix 1/8 ounce of concentrate with warm water, making one ounce. A measuring cup comes with the bottle. I have David swish with half the mixture for one minute. (Time it, because it’s longer than you think!) This rinse can only be used by kids who are old enough not to accidentally swallow it. Six-year-old David has no problem doing this once a day before he goes to bed. If and when he starts developing mouth sores, he will use it morning and evening. It’s important not to eat or drink for 30 minutes after rinsing. That is why David rinses before bedtime, after he has taken his meds and brushed his teeth.

• Serve bland food, baby food, or meals put through the blender.
• Use a straw with drinks or blender-processed foods.

Preston got bad mouth sores every time he was on high-dose methotrexate. He could not swallow, but we were supposed to be forcing fluids to flush the drugs out. The only thing that felt good on his throat was guava nectar. It was very expensive and hard to find, and he would drink several quarts a day. Unfortunately, my daughter and husband both developed a liking for it, too. At one point we cornered the market on guava nectar at three grocery stores in our neighborhood.

Several prescription products are available to treat mouth sores. One common product is called “magic mouthwash,” which contains an antibiotic, antihistamine, anti-fungal, and antacid. Some formulations add dexamethasone. More information about this product is available at www.mayoclinic.com/health/magic-mouthwash/AN02024. If your child has painful mouth sores, ask the oncologist for a prescription. Because large amounts of lidocaine can numb the back of the throat and cause difficulty swallowing, this medication should be used at a dose recommended by the oncologist.

Glutamine, a nutritional supplement available at most drug and health food stores, may help prevent or minimize mouth sores in some children. If your child is receiving chemotherapy with a high probability of causing mouth sores, you may want to try glutamine as a preventive measure. The powder can be mixed in juice and should be started one or two days before your child starts a cycle of chemotherapy. Be sure to get your oncologist’s approval before giving glutamine.