Your child needs to take the medicine called fluoxetine (say: flu-OKS-e-teen). This information sheet explains what fluoxetine does, how to give it, and what side effects or problems your child may have when he or she takes this medicine.

What is fluoxetine?

Fluoxetine is a medicine that works by increasing levels of a chemical in the brain called serotonin. It belongs to a class of medications called selective serotonin reuptake inhibitors (SSRIs)​. This medicine is used to treat depression, bulimia, or obsessive compulsive disorder.

You may hear fluoxetine called by its brand name, Prozac®. 

Fluoxetine comes in a capsule and a liquid form.

Before giving fluoxetine to your child

Tell your doctor if your child is:

  • allergic to fluoxetine or other medicines
  • taking any of these medicines:  thioridazine or medications in the monoamine oxidase inhibitor (MAO-I) drug class

Talk with the doctor or pharmacist if your child has any of the following conditions. Precautions may need to be taken with this medicine if your child has:

  • thoughts of suicide
  • bipolar disorder
  • liver or kidney disease: the dose of fluoxetine may need to be adjusted
  • a history of seizures
  • heart problems
  • diabetes mellitus: blood glucose levels may be affected

How should you give your child fluoxetine?

Follow these instructions when giving your child fluoxetine:

  • Give your child this medicine regularly, exactly as your doctor or pharmacist tells you. 
  • Give your child this medicine usually in the morning, although your doctor or pharmacist may give you a different schedule.
  • Give your child this medicine with or without food. Give fluoxetine with food if it causes an upset stomach.
  • If your child takes fluoxetine liquid, measure the dose carefully with the special spoon or oral syringe that the pharmacist gave you.
  • If your child has a feeding tube, flush the tube before and after fluoxetine liquid is given.

What should you do if your child misses a dose of fluoxetine?

  • Give the missed dose as soon as you remember.
  • If it is almost time for the next dose, skip the missed dose. Give the next dose at the regular time.
  • Do not give your child two doses to make up for one missed dose.

How long does fluoxetine take to work?

  • Your child may start to feel better a few weeks after starting this medicine.
  • It may take 6 weeks to see the full effect of fluoxetine.

What are the possible side effects of fluoxetine?

Your child may have some of these side effects while he or she takes fluoxetine. Check with your child's doctor if your child continues to have any of these side effects and they do not go away or they bother your child:

  • unusual tiredness, sleepiness, weakness, or difficulty thinking clearly: Have your child avoid tasks that require alertness until you see how this medicine affects him/her.
  • feeling nervous, excitable, irritable, or restlessness
  • headache
  • dizziness
  • nausea, vomiting (throwing up), or diarrhea (loose, watery stools): Taking the medicine with food or eating small frequent meals may help.
  • dry mouth (sucking on a hard candy or ice chips may help)
  • difficulty sleeping: Giving this medicine in the morning may help.

Most of the following side effects are not common, but they may be a sign of a serious problem. Call your child's doctor right away or take your child to the Emergency Department if your child has any of these side effects:

  • high fever, excessive sweating, confusion, shivering/shaking
  • seizures
  • unusual behaviour: rarely, fluoxetine may cause behaviour changes such as increased agitation, hostility, or thoughts of self-harm or harm to others
    If this happens, call your child’s doctor immediately but do not stop the fluoxetine on your own.
  • swelling of the face, tongue, or lips
  • sudden trouble in swallowing or breathing
  • shortness of breath
  • rash or itchy skin

What safety measures should you take when your child is using fluoxetine?

This medicine may cause your child to be less alert. Watch your child’s activities closely until you see how fluoxetine affects him/her. You may also have your child avoid tasks that require alertness such as riding a bicycle, rollerblading, and contact sports. 

Your child can get sunburned more easily. Avoid lots of sun, sunlamps, and tanning beds. Use sunscreen, dress your child in protective clothing, and encourage him/her to wear sunglasses.

Do not stop fluoxetine suddenly until you have talked to your child’s doctor first. The doctor may want to slowly decrease the dose of fluoxetine before stopping to prevent withdrawal symptoms (such as nausea, restlessness, trouble sleeping, sweating, dizziness, pins and needles feeling in hands or feet).

Keep your appointments with the doctor to have your child checked regularly.

It is important that you tell your doctor and pharmacist if your child takes any other medications (prescription, over the counter, or herbal) including lithium, St. John’s Wort, antidepressants (such as trazodone, SSRIs, MAO-Is), tryptophan, migraine medications (such as sumatriptan), linezolid, tramadol, certain heart medications, diazepam, or blood thinners (such as warfarin).

What other important information should you know about fluoxetine?

Keep a list of all medications your child is on and show the list to the doctor or pharmacist.

Do not share your child’s medicine with others. Do not give anyone else’s medicine to your child.

Make sure you always have enough fluoxetine to last through weekends, holidays, and vacations. Call your pharmacy at least 2 days before your child runs out of medicine to order refills.

Keep fluoxetine at room temperature in a cool, dry place away from sunlight. Do not store it in the bathroom or kitchen.

Do not keep any medicines that are out of date. Check with your pharmacist about the best way to throw away outdated or leftover medicines.

Keep fluoxetine out of your child’s sight and reach and locked up in a safe place. If your child takes too much fluoxetine, call the Ontario Poison Centre at one of these numbers. These calls are free.

  • Call 416-813-5900 if you live in Toronto.
  • Call 1-800-268-9017 if you live somewhere else in Ontario.
  • If you live outside of Ontario, call your local poison information centre.

Disclaimer: The information in this Family Med-aid is accurate at the time of printing. It provides a summary of information about fluoxetine and does not contain all possible information about this medicine. Not all side effects are listed. If you have any questions or want more information about fluoxetine, speak to your healthcare provider.

Jennifer Drynan-Arsenault, BSc, RPh, ACPR