Slenyto: Uses, Side Effects and Dosage

What SLENYTO is used for:

SLENYTO is used to treat sleeping problems (insomnia):

• in children and adolescents aged 2 to less than 18 years of age with autism spectrum disorder (ASD) and/or Smith-Magenis syndrome (SMS); and

• when a healthy sleeping routine (such as regular bedtime and soothing sleeping environment) has not worked well.

How SLENYTO works:

SLENYTO is a medicine that contains the active ingredient melatonin. It is a hormone that regulates the sleep-wake cycle. It is naturally produced by the brain at dusk and during the night. SLENYTO helps reduce the time it takes to fall asleep and improve the time spent sleeping in children and adolescents with ASD and/or SMS who often have difficulty with sleeping.

The ingredients in SLENYTO are:

Medicinal ingredient: melatonin

Non-medicinal ingredients: ammonio methacrylate copolymer type B (1 mg tablets only), ammonio methacrylate copolymer type A (5 mg tablets only), carboxymethylcellulose sodium, dextrose monohydrate, dibasic calcium phosphate dihydrate, ferric oxide red (1 mg tablets only), ferric oxide yellow, lactose monohydrate, lecithin soybean, magnesium stearate, maltodextrin, silicone dioxide, talc (1 mg tablets only), and titanium dioxide.

SLENYTO comes in the following dosage form:

Extended-release tablets; 1 mg and 5 mg.

Do not use SLENYTO if:

• you are allergic to melatonin or to any of the other ingredients in SLENYTO.

To help avoid side effects and ensure proper use, talk to your healthcare professional before you take SLENYTO. Talk about any health conditions or problems you may have, including if you:

• are taking any other medicines.

• consume alcohol.

• are a smoker.

• have the following rare hereditary conditions:

  • Galactose intolerance
  • Total lactase deficiency
  • Glucose-galactose malabsorption

SLENYTO contains lactose.

• have an autoimmune disease.
• have liver or kidney problems.
• have attention deficit hyperactivity disorder (ADHD).

• are pregnant, think you might be pregnant or are planning to become pregnant. SLENYTO is not recommended during pregnancy. Tell your healthcare professional right away if you discover that you are pregnant during treatment with SLENYTO.

• are breastfeeding or are planning to breastfeed. SLENYTO may pass into breastmilk and affect your breastfed baby. SLENYTO is not recommended while breastfeeding.

Other warnings you should know about:

Driving and using machines: SLENYTO can make you feel drowsy. This may affect your ability to drive, ride a bicycle or scooter, use tools or machinery. Before you do tasks requiring special attention, wait until you know how SLENYTO affects you. If you suffer from continued drowsiness, tell your healthcare professional.

Tell your healthcare professional about all the medicines you take, including any drugs, vitamins, minerals, natural supplements or alternative medicines.

The following may interact with SLENYTO:

• cimetidine (used to treat stomach problems such as heartburn and ulcers)
• rifampicin and quinolones such as ciprofloxacin and norfloxacin (used to treat bacterial infections)
• estrogens (used in contraceptives or hormone replacement therapy)

• medicines that can cause drowsiness, slowed breathing or induce sleep such as:

  • alcohol. Avoid drinking alcohol or taking medicines that contain alcohol during treatment with SLENYTO as it reduces its effectiveness.
  • antihistamines (used to treat allergies)
  • opioids (used to relieve pain)
  • benzodiazepines and non-benzodiazepine hypnotics such as zaleplon, zolpidem and zopiclone (used to induce sleep)
  • certain medicines used to treat depression (e.g., imipramine, amitriptyline)
  • fluvoxamine (used to treat depression and obsessive-compulsive disorder)
  • beta-blockers (used to control blood pressure). These medicines should be taken in the morning.
  • carbamazepine (used to treat epilepsy)
  • cannabis or other recreational drugs
• smoking. Tell your healthcare professional if you start or stop smoking during treatment. Your dose of SLENYTO may need to be adjusted.

How to take SLENYTO:

• Always take SLENYTO exactly as your healthcare professional has told you. Ask your healthcare professional if you are unsure.
• SLENYTO should be taken once daily, 30 to 60 minutes before bedtime.
• The tablets should be taken with or after food.
• Swallow tablets whole. Do NOT break, crush or chew tablets.
• The whole tablets can be put into food like yogurt, orange juice or ice cream to help with swallowing. If the tablets are mixed with these foods, they should be given immediately and not left or stored, as this may affect the way the tablets work. If the tablets are mixed with any other type of food, the tablets may not work properly.

Usual dose:

• The recommended starting dose is 2 mg (two 1 mg tablets) once daily. If there is no improvement in your symptoms, your healthcare professional may increase the dose of SLENYTO to find the most suitable dose for you.
• The maximum daily dose is 10 mg (two 5 mg tablets).
• You will be monitored regularly (every 6 months) by your healthcare professional. This is to check that SLENYTO is still the right treatment for you.
• Talk to your healthcare professional before you stop taking SLENYTO. It is important to continue taking this medicine to treat the condition.

Overdose:

If you think you, or a person you are caring for, have taken too much SLENYTO, contact a healthcare professional, hospital emergency department, regional poison control centre or Health Canada’s toll-free number, 1-844 POISON-X (1-844-764-7669) immediately, even if there are no signs or symptoms.

Missed dose:

If you forget to take a dose, take it as soon as you remember, before going to sleep that night. However, if the dose was forgotten after bedtime, skip the missed dose and take the next dose the next evening as usual.

Possible side effects from using SLENYTO:

These are not all the possible side effects you may have when taking SLENYTO. If you experience any side effects not listed here, tell your healthcare professional.

Side effects with SLENYTO may include:

• abdominal pain
• bad breath
• bedwetting
• blood in stool
• changes in appetite
• changes in mood
• constantly moving and/or excessive fidgeting, tapping or talking (hyperactivity)
• constipation
• cough
• decreased urination
• depression
• diarrhea
• difficulty returning to sleep
• dizziness
• dry mouth
• ear infection
• feeling irritable, aggressive or agitated
• feeling sleepy and lack of energy during the day, even after adequate sleep
• fever
• hangover feeling
• headache
• inappropriate emotional expression
• increased heartbeat
• irrational fear
• nausea
• nightmares
• repetitive movements, postures or spoken words
• runny nose
• skin rash
• stomach flu
• strong desire for sleep, sleeping for unusually long periods, or falling asleep suddenly
• swelling and inflammation of the sinuses (sinusitis)
• upper respiratory infection
• vomiting

Serious side effects and what to do about them

If you have a troublesome symptom or side effect that is not listed here or becomes bad enough to interfere with your daily activities, tell your healthcare professional.

Reporting side effects

You can report any suspected side effects associated with the use of health products to Health Canada by:

• Visiting the Web page on Adverse Reaction Reporting (canada.ca/drug-device-reporting) for information on how to report online, by mail or by fax; or
• Calling toll-free at 1-866-234-2345.

NOTE: Contact your healthcare professional if you need information about how to manage your side effects. The Canada Vigilance Program does not provide medical advice.

Storage:

• Store SLENYTO at room temperature (15°C to 30°C).
• Store in a cool dry place away from moisture, heat or sunlight (e.g., do not store it in the bathroom or near a sink, or in the car or on windowsills).
• Keep your tablets in the blister pack until it is time to take them. If you take the tablets out of the blister pack, they may not keep as well.
• Keep out of reach and sight of children.

If you want more information about SLENYTO:

• Talk to your healthcare professional
• Find the full product monograph that is prepared for healthcare professionals and includes the Patient Medication Information by visiting the Health Canada Drug Product Database website (https://www.canada.ca/en/health-canada/services/drugs-health-products/drug-products/drug-product-database.html); or by calling 1-877-258-3240.

Date of Authorization: 2025-09-08