Your child had a reaction to a medicine they took. Usually, these reactions happen because someone:

• is sensitive to something in the medicine (for example, a dye)
• is allergic to the medicine
• takes more than one medicine at a time and the medicines have an unexpected effect on each other

Reactions to medicine can range from mild to serious and can include a rash, headache, belly pain, upset stomach, vomiting, diarrhea, or an allergic reaction. Although it is rare, some medicines may cause problems with the liver or kidneys.

• Follow your health care provider's advice about:
  • whether your child should stop taking the medicine or take a different one
  • giving your child any medicines (such as an antihistamine for itching or a steroid after an allergic reaction)
  • whether your child needs to change their diet (for example, they may need a bland diet or another diet if they had an upset stomach or diarrhea)
  • whether your child needs to avoid some types of medicines, foods, or supplements when taking certain medicines
  • going to see any specialists (such as an allergist)
  • when to follow up
• Do not give the medicine(s) that caused the reaction again unless you check with your health care provider first.
• If your child had an allergic reaction to the medicine, tell all their health care providers and pharmacists so this can be put in your child's medical record.

Your child is taking a medicine and has new symptoms, such as a rash, headache, belly pain, upset stomach, vomiting, or diarrhea.

Your child has signs of a serious allergic reaction, such as a swollen face, lips, or tongue; hoarseness; repeated vomiting; wheezing; trouble breathing; or passing out.

Can medicine reactions be prevented? Not all reactions can be prevented, but it can help to:

• Give your child medicines exactly as prescribed.
• Read all labels and inserts to make sure the medicine is OK for your child.
• Don't give your child medicine meant for someone else.
• Make sure your pharmacist and health care provider know about any medicines your child takes before you add another medicine.
• Avoid giving your child any medicine that caused a reaction in the past (unless your health care provider tells you this is safe).
• Store medicine correctly.
• Don't use expired medicine.

Is there any way to know if someone will react to a medicine? There's no way to know for sure if someone will have a reaction to a medicine. A person could have a reaction to a medicine they've taken in the past without problems. A reaction can happen the first time someone takes a medicine, after they've taken it for a while, and sometimes even after they stop taking it.