Common Side Effects of Pediatric Drugs

Learn More About the Side Effects of Specific Childhood Medications

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Nowadays, parents and pediatricians are becoming much more aware of the possible side effects of the medications that kids are being prescribed. 

Parents may be more cautious as a result of some high-profile reports about possible drug side effects, which has likely helped to get everyone's attention in recent years, including:

  • Singulair (montelukast) and a possible association with behavior/mood changes, suicidal thoughts and behaviors, and suicide
  • Over-the-counter cough and cold medicines and the FDA alert that the risks of taking them may outweigh the benefits for children under age 2
  • Tamiflu (oseltamivir) and a variety of neurologic and behavioral symptoms, including hallucinations, delirium and abnormal behavior
  • Antidepressants and the increased risk of suicidal thoughts and behavior in children and adolescents being treated with antidepressant medications
  • Accutane (isotretinoin) and the possible risk of birth defects and psychiatric effects (e.g., suicidal thoughts, behaviors and suicide)

Although it is good to be aware of all possible risks when your child is being prescribed a medication, it can also sometimes work to limit a child's access to highly beneficial medication, where the benefits would have far outweighed the possible risks.

This is especially common when a parent doesn't want to treat their children with preventative steroid medications when they have asthma, because they are worried about the possible side effects of inhaled steroids.

All Medications Can Have Side Effects

To highlight that point, some people say that if you read about all of the possible side effects of commonly used over-the-counter medicines, such as Tylenol or Motrin, then you would likely never take them. Some of the most common side effects of medications include:

  • Headache
  • Nausea
  • Insomnia
  • Dizziness
  • Anxiety
  • Diarrhea
  • Skin rashes
  • Abdominal pain
  • Fatigue
  • Sleepiness
  • Weight gain
  • Allergic reactions

These side effects usually only occur in a small percentage of children, so there is a good chance your child won't have any side effects when taking any specific medicine. Also, almost all drug side effects are temporary and go away once you stop the medicine or switch to a different medicine.

Specific Drug Reactions in Children

In addition to the general drug side effects listed above, which can occur with almost any medicine, there are some side effects that are more commonly seen with specific medications.

Some of the more classic drug side effects that you may encounter or should be on the watch for include:

  • Amoxil (Amoxicillin). As with other antibiotics, the most common side effects of Amoxil can include diarrhea, nausea and vomiting. In addition, Amoxil sometimes causes behavioral changes, including hyperactivity and agitation.
  • Prednisone. Even in the small short-term dosages that are used to treat asthma and poison ivy, the most common prednisone side effects can include mood changes, nervousness and insomnia.
  • Benadryl (diphenhydramine). As with many other antihistamines, Benadryl's side effects usually include drowsiness and a dry mouth, which is often why many pediatricians recommend that children with regular allergies take a less sedating or nonsedating allergy medication, such as Allegra (fexofenadine), Claritin (loratadine), Clarinex (desloratadine) or Zyrtec (cetirizine) instead.
  • Ritalin (methylphenidate). Concerta is the most common form of Ritalin, and its side effects can include a loss of appetite, nausea, stomach pain, insomnia, nervousness, headache and dizziness.
  • Flonase (fluticasone). As with other steroid nasal allergy nose sprays, the most common side effects can include cough, nasal irritation and nosebleeds.
  • Vyvanse (lisdexamfetamine). As with other forms of dextroamphetamine, such as Adderall and Adderall XR that are used to treat ADHD, common Vyvanse side effects include decreased appetite, headache, trouble sleeping, weight loss, abdominal pain, irritability and vomiting.
  • Reglan (metoclopramide). Common side effects of Reglan (sometimes used to treat children with reflux) include diarrhea, headache, nausea, insomnia, restlessness and decreased energy. It is the less common, but more serious, acute dystonic reactions and tardive dyskinesia, with involuntary movements, that sometimes limit the use of this medicine in pediatrics.
  • Omnicef (cefdinir). As with other antibiotics, the most common Omnicef side effects can include diarrhea, nausea and vomiting. In addition, Omnicef can sometimes causes a child's stool to have a reddish color, because of the interaction with iron vitamins, baby formula with iron or other iron-containing products.
  • Pyridium (phenazopyridine). Although not often used in pediatrics, the most common side effect of Pyridium is that it can cause urine to turn a reddish orange color and staining of contact lenses. Pyridium is sometimes used for the symptomatic treatment of urinary tract infections.

Recognizing Drug Side Effects

Although parents often blame new symptoms on medications, how do you know if a symptom is actually a side effect of a medication and is not being caused by something else?

Say your child is sick with a sinus infection and after taking an Amoxi, starts having diarrhea three days later. Is the diarrhea a specific side effect of Amoxil, a general side effect of taking an antibiotic, or the stomach flu that is also going through your child's daycare at the same time?

To help you recognize if your child is having a side effect to a medication, it can help to:

  • keep a detailed record of when your child starts, stops or changes dosages of any medication he takes
  • record any new symptoms when starting a new medication or changing dosages
  • ask your pediatrician and pharmacist about common side effects of medications your child is prescribed so that you know what to watch for
  • compare any unexplained symptoms that your child is having to the list of common side effects and uncommon side effects that are included on the medication's package insert
  • follow the directions when you give your child a medication, especially for medications such as Lindane which is an FDA approved second-line treatment used to treat head lice, but can cause serious side effects even when used properly
  • tell your pediatrician and pharmacist about all other medications your child is taking, including over-the-counter medications, alternative therapies and vitamins to help them recognize any possible drug interactions that may lead to worsening drug side effects

Reporting Drug Side Effects

In addition to reporting drug side effects to your pediatrician, so that you can make a medication change, parents and pediatricians can report drug side effects directly to the FDA's MedWatch Safety Information and Adverse Event Reporting Program.

Medwatch is just for FDA-regulated drugs, medical devices and some other products, but does not include vaccines. Vaccine side effects should instead be reported to the Vaccine Adverse Event Reporting System (VAERS).


FDA Public Health Advisory. Nonprescription Cough and Cold Medicine Use in Children. August 15, 2007.

Physicians' Desk Reference. PDR 62. 2008.

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