Your child needs to take a medication called deflazacort. This information sheet explains what deflazacort does, how to give and what side effects or problems your child may have when they take this medication.
What is deflazacort?
Deflazacort is a corticosteroid medication used to treat Duchenne muscular dystrophy (DMD). Deflazacort is not the same kind of steroid that athletes use to enhance their performance and will not cause the same types of side effects.
You may hear Deflazacort called by one of its brand names, Emflaza. Deflazacort comes in tablet form.
How does deflazacort work?
Deflazacort works by reducing inflammation, which helps protect muscle strength and function over time.
Deflazacort helps in the following ways:
- Muscle strength: Deflazacort helps children stay stronger longer, making it easier to do daily activities such as climbing stairs.
- Walking ability: Children taking deflazacort are often able to keep walking on their own for a longer time compared to those who do not take it.
- Heart health: Deflazacort helps keep the heart healthier, which is important because DMD can affect heart function.
- Spinal health: This medication also lowers the chance of spine problems, such as scoliosis, and reduces the need for surgeries to correct these issues.
Before taking deflazacort
Talk with your child’s health-care provider about any of the following:
- Allergies: Let your child’s health-care provider and pharmacist know if your child is allergic to deflazacort or any of its ingredients.
- Other medications: Tell your child’s health-care provider about any other medications, vitamins or supplements your child is taking, including herbal products such as St. John’s wort, which can interact with deflazacort.
- Medical history: Share your child’s medical history with their health-care provider, especially if they have had liver, kidney or heart issues, eye conditions (e.g., cataracts or glaucoma), infections, mental health conditions, diabetes or osteoporosis.
- Surgery: If your child needs any type of surgery, tell their health-care provider or dentist that they are taking deflazacort. Your child may need an additional dose to help prevent further muscle weakness.
- Vaccinations: Make sure your child has any needed immunizations before starting deflazacort and discuss routine immunizations with your child’s health-care provider while they are taking deflazacort.
- Infection risks: Deflazacort can lower your child’s ability to fight infections, so wash hands frequently, avoid people who are sick and stay away from anyone with chickenpox or measles. Contact your child's health-care provider if you think your child has been exposed.
- Dietary precautions: Do not eat grapefruit or drink grapefruit juice while taking this medication. Check fruit juices for grapefruit content, as some tropical juices may contain grapefruit juice.
How to give deflazacort to your child
Give your child deflazacort at the same time(s) every day.
Try to give deflazacort in the morning, with a snack or meal, to reduce stomach upset. Giving it too late in the day may interfere with sleep.
The tablet may be cut or crushed for ease of giving it and can be mixed with food to help with swallowing it.
You can give deflazacort with food or drink. Ensure it is only mixed with a very small amount of liquid or food to ensure your child takes the full dose.
Follow your child’s health-care team’s instructions closely for the correct dose and timing.
What should you do if your child misses a dose of deflazacort?
- 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 two doses to make up for one missed dose.
What are the possible side effects of deflazacort?
Steroids such as deflazacort help people with DMD feel better by slowing down muscle damage. However, these medicines can have side effects that need careful watching and managing.
- Bone health: Deflazacort can make bones weaker, which means they might break more easily. Your child’s health-care team may prescribe medications to help strengthen bones and suggest extra calcium and vitamin D.
- Immune system: Deflazacort can affect the immune system, making it harder for the body to fight germs. Making sure that everyone in the family, not just the child with DMD, gets all of their vaccinations, including an annual flu shot, helps to keep your child safer.
- Cataracts in the eyes: This can make the lens of the eye cloudy and can hurt vision.
- Fat storage: Deflazacort can change the way the body stores fat, sometimes leading to extra fat in places such as the face or belly. In addition, it may increase the risk of diabetes and heart problems.
- Adrenal suppression: The adrenal glands are small organs that help the body deal with stress by making special hormones. Deflazacort can slow down how these glands work, so that when the body is under stress, such as during an illness or surgery, it might not make enough stress hormones. To help with this, your child may be prescribed medication called hydrocortisone.
What safety measures should you take when your child is using deflazacort?
There are some medicines that should not be taken together with deflazacort. It is important that you tell your child’s health-care provider and pharmacist if your child takes any other medications (prescription, over the counter or herbal).
Examples include:
- select antifungal medications: clarithromycin, fluconazole
- certain heart medications: diltiazem, verapamil
- certain seizure medications, including carbamazepine and phenytoin
- select antibiotics used to treat tuberculosis, such as rifampin
- acetylsalicylic acid (ASA or Aspirin)
- diabetes medications
Taking deflazacort with certain over-the-counter pain and fever medications, called non-steroidal anti-inflammatory drugs—such as ibuprofen, diclofenac and naproxen—could increase the likelihood of bleeding and could lead to serious stomach upset or bleeding. While small quantities taken for a few doses is likely to be safe, it is preferrable to use acetaminophen (Tylenol) first to avoid these effects. Taking deflazacort with food or drink will also help reduce the likelihood of serious stomach upset.
Do I need to follow up after starting deflazacort?
It is important to follow up with your child’s neurologist after starting deflazacort to make sure it is working properly and to check if any dose adjustments are needed. During these visits, make sure to mention any discomfort or side effects your child may be experiencing so the health-care team can help manage them. Regular check-ins with your child’s health-care team will help make sure the medication is providing the best benefit for your child.
References
Drugbank. (2026). Deflazacort. https://go.drugbank.com/drugs/DB11921
Lexicomp. (2026). Deflazacort.
MedlinePlus. (2026). Deflazacort. https://medlineplus.gov/druginfo/meds/a617024.html
At SickKids
SickKids has a specialized neuromuscular clinic that focuses on DMD and similar conditions. The clinic is located within the Neurology Department and is staffed by a neurologist, nurse practitioner and experienced technicians who are dedicated to caring for children with DMD. Our clinic visits range from simple follow-ups to more specialized procedures, such as nerve conduction studies and electromyography. Additionally, we offer access to a professional social worker who can provide support for both you and your child and connect you with relevant support groups if needed. You are not alone in this journey!
To learn more about the Neuromuscular Program at SickKids, visit https://www.sickkids.ca/en/care-services/clinical-departments/neurology/neuromuscular-program/.
Keep deflazacort out of your child’s sight and reach and locked up in a safe place. If your child takes too much deflazacort, call your local Poison Information Centre at one of these numbers. These calls are free.
- Call 1-844 POISON-X, or 1-844-764-7669, from anywhere in Canada except Quebec.
- Call 1-800-463-5060 if you live in Quebec.