M-Eslon: Uses, Side Effects and Dosage

Serious warnings and precautions box

What M-ESLON is used for:

M-ESLON is used in adults to manage long-term pain, when:

• the pain is severe enough to require daily, around-the-clock pain medications; and
• the healthcare professional determines that other treatment options are not able to effectively manage your pain.

It is NOT used “as needed” to treat pain that you only have once in a while.

How M-ESLON works:

M-ESLON is a painkiller belonging to the class of medicines known as opioids. It relieves pain by acting on specific nerve cells of the spinal cord and brain.

The ingredients in M-ESLON are:

Medicinal ingredient: Morphine sulfate

Non-medicinal ingredients: Dibutyl sebacate, gelatin, maize starch, polyethylene glycol 4000, polymeric dispersion of ethylcellulose, sucrose, talc, and titanium dioxide.

The capsule shells contain the following additional ingredients:

• 15 mg: Quinoline yellow WS (D&C Yellow No. 10)
• 30 mg: Erythrosine (FD&C Red No. 3)
• 60 mg: Sunset yellow FCF (FD&C Yellow No. 6)
• 100 mg: Black iron oxide
• 200 mg: Allura red AC (FD&C Red No. 40), brilliant blue FCF (FD&C Blue No. 1)

M-ESLON comes in the following dosage form:

M-ESLON extended release capsules are available in 6 strengths:

• 10 mg (opaque white cap and body capsule with “M-ESLON” and “10” printed in black)
• 15 mg (opaque yellow cap and transparent natural body capsule with “M-ESLON” and “15” printed in black)
• 30 mg (opaque pink cap and transparent natural body capsule with “M-ESLON” and “30” printed in black)
• 60 mg (opaque orange cap and transparent natural body capsule with “M-ESLON” and “60” printed in black)
• 100 mg (opaque gray cap and transparent natural body capsule with “M-ESLON” and “100” printed in white)
• 200 mg (opaque red cap and transparent natural body capsule with “M-ESLON” and “200” printed in white)

Do not use M-ESLON if:

• your healthcare professional did not prescribe it for you.
• you are allergic to morphine sulfate, other opioids, or any of the other ingredients of M-ESLON.
• you have mild or short term pain that can be controlled by the occasional use of painkillers, including those available without a prescription.
• you have severe asthma, trouble breathing, or other lung problems.
• you have an irregular heartbeat or low blood pressure.
• you have bowel blockage or narrowing of the stomach or intestines.
• you have a condition where the bowel does not work properly (ileus).
• you have severe pain in your abdomen (for example, from appendicitis or pancreatitis).
• you have increased pressure in your skull, have a head injury, or a brain tumour.
• you have gallbladder disease, bile duct disease or problems with your pancreas.
• you have or have had a history of epilepsy.
• you suffer from alcoholism or alcoholism withdrawal.
• you are pregnant or plan to become pregnant or are in labour and delivery.
• you are breast-feeding.
• you have a surgical connection between tubular structures, such as blood vessels or loops of intestine.
• you have severe cirrhosis of the liver.
• you had surgery of the biliary tract.
• you are taking or have taken within the past 2 weeks a monoamine oxidase inhibitor (MAOI) (such as phenelzine sulfate, tranylcypromine sulfate, moclobemide, or selegiline).

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

• have a personal or family history of illicit or prescription drug or alcohol abuse.
• you are going to have, or recently had, a planned surgery;
• have been told that you have a low red blood cell count.
• have kidney or liver problems.
• have a sleep disorder which causes pauses in breathing or shallow breathing while sleeping (sleep apnea).
• suffer from chronic or severe constipation.
• have problems with your thyroid, adrenal or prostate gland.
• suffer from migraines.
• have or have had problems with your mood (such as depression or anxiety), hallucinations, or other mental health problems.
• have gastrointestinal (GI) problems.
• have a history of pancreas or gall bladder problems.
• are planning to breastfeed.
• are over 50 years of age.
• have circulatory problems (e.g., body does not get enough oxygen and nutrients to function properly due to lack of blood flow).
• have sickle cell disease.
• have difficulty urinating.
• have a condition that causes weakness or frailty.
• are planning on drinking alcohol. Drinking alcohol while taking M-ESLON may cause dangerous side effects, including death. Do NOT drink alcohol while taking M-ESLON.
• take hypnotics, centrally acting analgesics, opioids, or psychotropic medicines. Ask your healthcare professional if you are unsure.

Other warnings you should know about:

Taking M-ESLON can cause the following serious side effects:

• Disorder of the adrenal gland: You may develop a disorder of the adrenal gland called adrenal insufficiency.

  • This means that your adrenal gland is not making enough of certain hormones. You may experience symptoms such as:
  • nausea, vomiting;
  • feeling tired, weak or dizzy;
  • decreased appetite.

You may be more likely to have problems with your adrenal gland if you have been taking opioids for longer than one month. Your healthcare professional may do tests, give you another medication, and slowly take you off M-ESLON.

• Serotonin toxicity (also known as serotonin syndrome): M-ESLON can cause serotonin toxicity, a rare but potentially life-threatening condition. It can cause serious changes in how your brain, muscles, and digestive system work. You may develop serotonin toxicity if you take M-ESLON with certain anti-depressants or migraine medications. Serotonin toxicity symptoms include:

  • fever, sweating, shivering, diarrhea, nausea, vomiting;
  • muscle shakes, jerks, twitches or stiffness, overactive reflexes, loss of coordination;
  • fast heartbeat, changes in blood pressure;
  • confusion, agitation, restlessness, hallucinations, mood changes, unconsciousness, and coma.
• Sleep apnea: Opioids can cause a problem called sleep apnea (stopping breathing from time to time while sleeping). Tell your healthcare professional if you have a history of sleep apnea or if anyone notices that you stop breathing from time to time while sleeping.

See the Serious side effects and what to do about them table for more information on these and other serious side effects.

Opioid dependence and addiction: Like any opioid, M-ESLON may cause mental and physical dependence. Morphine sulfate also has the potential to cause addiction even at regular doses. There are important differences between physical dependence and addiction. Tolerance means that, over time, a higher dose may be needed to get the same level of pain relief. It is important that you talk to your healthcare professional if you have questions or concerns about abuse, addiction, physical dependence, or tolerance. Your healthcare professional should prescribe and administer M-ESLON with the same degree of caution appropriate to the use of other oral opioid medications. It is not recommended to use these products for a long period of time.

Pregnancy, nursing, labour and delivery: Do not use M-ESLON while pregnant, nursing, during labour or delivery. Opioids can be transferred to your baby through breast milk, or while still in the womb. M-ESLON can then cause life-threatening breathing problems in your unborn baby or nursing infant.

If you are pregnant and are taking M-ESLON, it is important that you don’t stop taking your medication all of a sudden. If you do, it can cause a miscarriage or a still-birth. Your healthcare professional will monitor and guide you on how to slowly stop taking M-ESLON. This may help avoid serious harm to your unborn baby.

Driving and using machines: Before you do tasks which may require special attention, you should wait until you know how you react to M-ESLON. M-ESLON can cause:

• drowsiness,
• dizziness, or
• light headedness.

This can usually occur after you take your first dose and when your dose is increased.

Sexual function and reproduction: Long term use of opioids may lead to a decrease in sex hormone levels. It may also lead to low libido (desire to have sex), erectile dysfunction or being infertile.

Worsening pain: Taking opioids for pain can sometimes have the unintended effect of making your pain feel worse (opioid-induced hyperalgesia) even though your opioid dose has been unchanged or increased. This can also include feeling pain in new places in your body, or feeling pain from something that would not normally hurt, for example, feeling pain from clothing touching your skin. Tell your healthcare professional if you notice a change like this in your pain while you are taking M-ESLON.

Testing and check-ups: Your healthcare professional will regularly monitor your health. This includes monitoring for signs of:

• misuse and abuse;
• sleep apnea (a sleep disorder which causes pauses in breathing or shallow breathing while sleeping);
• respiratory depression and sedation (e.g., slow, shallow, or weak breathing).

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

Serious drug interactions

The following may also interact with M-ESLON:

• rifampicin, used to treat bacterial infections
• anticoagulants, used to thin the blood and prevent blood clots (e.g., warfarin and other coumarin)
• drugs used to treat migraines (e.g., triptans)
• anti-retroviral, anti-fungal and antibiotic drugs

How to take M-ESLON:

• M-ESLON must be taken orally, by mouth. Do NOT administer the M-ESLON capsules via any other routes as this can cause serious harm, including death.
• Take M-ESLON every 12 hours as prescribed, with 120 mL to 180 mL of water.

• Swallow whole. Do not break, crush, chew or dissolve the capsule. This can be dangerous and can lead to death or seriously harm you. The capsules may be opened and the contents sprinkled onto soft food or mixed in liquids or taken by specific feeding tubes if necessary.

• M-ESLON should not be used longer than necessary.

Usual dose:

Your dose is tailored/personalized just for you. Take it exactly as your healthcare professional has told you to. Do not increase or decrease your dose without consulting your healthcare professional. Taking higher doses can lead to more side effects and a greater chance of overdose.

Review your pain regularly with your healthcare professional to determine if you still need M-ESLON. Be sure to use M-ESLON only for the condition for which it was prescribed.

If your pain increases or you develop any side effect as a result of taking M-ESLON, tell your healthcare professional immediately.

Stopping your Medication:

If you have been taking M-ESLON for more than a few days, you should not stop taking it all of a sudden. Your healthcare professional will monitor and guide you on how to slowly stop taking M-ESLON. You should do it slowly to avoid uncomfortable symptoms such as having:

• body aches
• diarrhea
• goosebumps
• loss of appetite
• nausea
• feeling nervous or restless
• runny nose
• sneezing
• tremors or shivering
• stomach cramps
• rapid heart rate (tachycardia)
• having trouble sleeping
• an unusual increase in sweating
• heart palpitations
• an unexplained fever
• weakness
• yawning.

By reducing or stopping your opioid treatment, your body will become less used to opioids. If you start treatment again, you will need to start at the lowest dose. You may overdose if you restart at the last dose you took before you slowly stopped taking M-ESLON.

Refilling Prescriptions for M-ESLON:

A new written prescription is required from your healthcare professional each time you need more M-ESLON. Therefore, it is important that you contact your healthcare professional before your current supply runs out.

Only obtain prescriptions for this medicine from the healthcare professional in charge of your treatment. Do not seek prescriptions from other healthcare professionals unless you switch to another healthcare professional for your pain management.

Overdose:

If you think you, or a person you are caring for, have taken too much M-ESLON, contact a healthcare professional, hospital emergency department, regional Poison Control Centre or Health Canada’s tollfree number, 1-844 POISON-X (1-844-764-7669) immediately, even if there are no signs or symptoms.

Signs of overdose with M-ESLON may include:

• unusually slow or weak breathing
• dizziness
• confusion
• extreme drowsiness
• shrinking of the pupils
• lack of muscle shape and tone
• cold and clammy skin
• slow heart rate
• low blood pressure
• muscle weakness, cramping, or aching
• toxic leukoencephalopathy (a brain disorder affecting the brain’s white matter)

Missed dose:

It is important that you do not miss any doses. If you miss:

• one dose: skip the missed dose and take your next dose as scheduled. Do not take two doses at once to make up for a missed dose.
• several doses in a row: talk to your healthcare professional before restarting your medication.

Possible side effects from using M-ESLON:

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

Side effects with M-ESLON may include:

• Drowsiness
• Insomnia
• Dizziness
• Fainting
• Nausea, vomiting, or a poor appetite
• Dry mouth
• Headache
• Problems with vision
• Weakness, uncoordinated muscle movement
• Itching
• Rash
• Sweating
• Constipation. Talk with your healthcare professional about ways to prevent constipation when you start using M-ESLON.
• Low sex drive, impotence (erectile dysfunction), infertility
• Severe pain in your abdomen that comes and goes [e.g., spasm of the sphincter of Oddi (muscle that controls the flow of bile and pancreatic fluid into the intestine)]

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

Storage:

• Store capsules at room temperature (15°C - 30°C).
• Keep unused or expired M-ESLON in a secure place to prevent theft, misuse or accidental exposure.
• Keep M-ESLON under lock, out of sight and reach of children and pets.
• Never take medicine in front of small children as they will want to copy you. Accidental ingestion by a child is dangerous and may result in death. If a child accidentally takes M-ESLON, get emergency help right away.

Disposal:

M-ESLON should never be thrown into household trash, where children and pets may find it. It should be returned to a pharmacy for proper disposal.

If you want more information about M-ESLON:

• 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); the manufacturer’s website at www.ethypharm.com/ethypharm-canada/; or by calling 1-800-347-1675.

Date of Authorization: 2026-09-17