Apo-Methadone: Uses, Side Effects and Dosage

Serious Warnings and Precautions

• Even if you take APO-METHADONE as prescribed you are at risk for opioid addiction, abuse and misuse. This can lead to overdose and death. To understand your risk of opioid addiction, abuse, and misuse you should speak to your healthcare professional.
• Life-threatening breathing problems can happen while taking APO-METHADONE, especially if not taken as directed. Babies are at risk of life-threatening breathing problems if their mothers take opioids while pregnant or nursing.
• APO-METHADONE may cause heartbeat problems that can be life-threatening in rare cases. Symptoms may include fainting, heart palpitations (feeling a rapid, pounding or irregular heartbeat), dizziness or lightheadedness. If you think you might have heartbeat or heart rhythm problems, get immediate medical help.
• Never give anyone your APO-METHADONE. They could die from taking it. If a person has not been prescribed APO-METHADONE, taking even one dose can cause a fatal overdose. This is especially true for children.

• If you took APO-METHADONE while you were pregnant, whether for short or long periods of time or in small or large doses, your baby can suffer life-threatening withdrawal symptoms after birth. This can occur in the days after birth and for up to 4 weeks after delivery. If your baby has any of the following symptoms:

  • has changes in their breathing (such as weak, difficult or fast breathing)
  • is unusually difficult to comfort
  • has tremors (shakiness)
  • has increased stools, sneezing, yawning, vomiting, or fever

Seek immediate medical help for your baby.

• Taking APO-METHADONE with other opioid medicines, benzodiazepines, alcohol, or other central nervous system depressants (including street drugs) can cause severe drowsiness, decreased awareness, breathing problems, coma, and death.

What is APO-METHADONE used for?

APO-METHADONE is used in adults for the long-term management of pain, when:

• The pain is severe enough to require daily, around-the-clock painkillers
• The healthcare professional determines that other treatment options are not able to effectively treat your pain

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

How does APO-METHADONE work?

APO-METHADONE 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.

What are the ingredients in APO-METHADONE?

Medicinal ingredient: methadone hydrochloride

Non-medicinal ingredients: magnesium stearate, mannitol, microcrystalline cellulose and tromethamine

The following tablet strengths also contain:

• 1 mg: FD&C Blue No. 1
• 5 mg: FD&C Yellow No. 6
• 10 mg: D&C Yellow No.10 aluminium, FD&C Blue No. 1

APO-METHADONE comes in the following dosage form:

Tablets: 1 mg, 5 mg, 10 mg and 25 mg

Do not use APO-METHADONE if:

• your healthcare professional did not prescribe it for you
• you are allergic to methadone hydrochloride, other opioids or any of the other ingredients in APO-METHADONE
• you have never taken an opioid before
• you can control your pain by the occasional use of other pain medications. This includes those available without a prescription
• you have severe asthma, trouble breathing or cor pulmonale (a heart problem related to lung issues)
• you have any heart problems
• you have bowel blockage or narrowing of the stomach or intestines
• you have a condition where the bowel does not work properly (ileus) or have severe pain in your abdomen
• you have severe diarrhea caused by antibiotics or food poisoning
• you have a head injury or other risks for seizure
• you suffer from alcoholism or alcohol withdrawal
• you are going to have a surgery or operation, or have had a surgery within the last 24 hours
• you are taking, or have taken within the past 14 days, a certain type of antidepressant called Monoamine Oxidase Inhibitor (MAOIs)
• you are pregnant or planning to become pregnant, or you are in labour or delivery
• you are breastfeeding

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

• have a history of illicit drugs or prescription drug or alcohol abuse
• you are taking any other medications
• are drinking or planning to drink alcohol, or take medications that contain alcohol
• have, or are at risk for, heart disease or heart rhythm problems. Ask your healthcare professional if you are not sure
• have low blood pressure
• have kidney or liver problems
• have problems with your thyroid, adrenal or prostate gland
• have epilepsy or a history of seizures (convulsions)
• are over 65 years of age
• have a sleep disorder which causes pauses in breathing or shallow breathing while sleeping (sleep apnea)
• have, or have a history or, problems with your mood (such as depression or anxiety), or other mental health problems
• have difficulty urinating
• suffer from chronic or severe constipation
• suffer from migraines

Other warnings you should know about:

Opioid dependence and addiction: Like any opioid, APO-METHADONE may cause mental and physical dependence; it also has the potential to cause addiction. There are important differences between physical dependence and addiction. If you use opioids for a long time, you may develop tolerance. This means that you may need higher doses of APO-METHADONE to feel the same level of pain relief. It is important that you talk to your healthcare professional if you have questions or concerns about addiction, physical dependence, or tolerance. Your healthcare professional should prescribe and administer APO-METHADONE 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 APO-METHADONE while pregnant, nursing, during labour or delivery. Opioids can be transferred to your baby through breast milk, or while still in the womb. APO-METHADONE can then cause life-threatening breathing problems in your unborn baby or nursing infant.

If you are pregnant and are taking APO-METHADONE, 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 APO-METHADONE. 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 APO-METHADONE. APO-METHADONE can cause:

• drowsiness
• dizziness or
• light headedness

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

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 APO-METHADONE.

Serotonin toxicity (also known as serotonin syndrome): APO-METHADONE 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 APO-METHADONE 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.

Sexual Function/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.

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.

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 APO-METHADONE.

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)
• low blood pressure
• problems with your heart rhythm.

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

Serious Drug Interactions

Serious drug interactions with APO-METHADONE include:

• benzodiazepines used to help you sleep or that help reduce anxiety.

• central nervous system (CNS) depressants used to slow down the nervous system. These can include:

  • alcohol. This includes prescription and non-prescription medications that contain alcohol. Do not drink alcohol while you are taking APO-METHADONE. It can lead to drowsiness, unusually slow or weak breathing, serious side effects, or a fatal overdose.
  • other opioids and mixed opioid agonists/antagonists used to relieve pain (e.g., pentazocine, nalbuphine, butorphanol, and buprenorphine);
  • anesthetics used during surgery;
  • hypnotics used to help with sleeping;
  • antidepressants used for depression and mood disorders (e.g., tricyclic antidepressants; serotonin norepinephrine re-uptake inhibitors (SNRIs); and selective serotonin re-uptake inhibitors (SSRIs) such as sertraline and St. John’s Wort);
  • anxiolytics, tranquilizers, and phenothiazines used to treat mental or emotional disorders;
  • muscle relaxants used to treat muscle spasms and back pain (e.g., baclofen);
  • antipsychotics and neuroleptics used to treat mental health disorders;
  • antihistamines used to treat allergies;
  • antiemetics used to prevent nausea or vomiting;
  • sedatives which may enhance the drowsiness;
  • pregabalin, used to treat nerve pain;
  • gabapentin, used to prevent and control seizures in the treatment of epilepsy;
  • beta blockers used to lower blood pressure;
• monoamine oxidase inhibitors (MAOIs) used to treat depression. Do not take APO-METHADONE with MAOIs or if you have taken MAOI’s in the last 14 days.

The following may also interact with APO-METHADONE:

• anticonvulsants used to treat seizures (e.g., phenytoin, carbamazepine, phenobarbital)
• anticoagulants used to thin the blood and prevent blood clots (e.g., warfarin and other coumarins)
• antiretrovirals used to treat viral infections (e.g., nevirapine, efavirenz, ritonavir, lopinavir, zidovudine, didanosine, stavudine)
• antifungals used to treat fungal infections (e.g., ketoconazole, voriconazole)
• antibiotics used to treat bacterial infections (e.g., erythromycin, rifampin)
• medicines used to treat migraines (e.g., triptans)
• antiarrhythmics used to treat an abnormal heart rhythm
• calcium channel blockers used to lower blood pressure
• medicines used to regulate salt and water balances in the body (e.g., diuretics, mineralocorticoid hormones, laxatives)

How to take APO-METHADONE:

• Take APO-METHADONE exactly as your healthcare professional tells you to. Do NOT increase, decrease, or stop taking your dose without talking to your healthcare .
• APO-METHADONE must be taken orally, by mouth. Do NOT take APO-METHADONE any other way.
• Swallow APO-METHADONE tablets whole. Do not break, chew, dissolve or crush.
• Do not use APO-METHADONE for injection or rectal administration.

Usual dose:

Your dose is tailored/personalized just for you. Your healthcare professional will prescribe you the lowest dose that works to control your pain. During treatment, your healthcare professional may adjust your dose based on the severity of your pain and your response to the treatment. Follow their instructions closely.

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

If your pain increases or you develop any side effects as a result of taking APO-METHADONE, tell your healthcare professional immediately.

Stopping your Medication:

If you have been taking APO-METHADONE 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 APO-METHADONE. 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 with sleeping
• an unusual increase in sweating
• heart palpitations
• an unexplained fever
• weakness
• vomiting
• 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 APO-METHADONE.

Refilling your prescription for APO-METHADONE:

A new written prescription is required from your healthcare professional each time you need more APO-METHADONE. 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 APO-METHADONE, 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.

Signs of overdose with APO-METHADONE may include:

• unusually slow or weak breathing
• dizziness;
• confusion;
• extreme drowsiness;
• muscle weakness;
• cold and clammy skin;
• slow heart rate;
• shrinking or widening of pupils.

Missed dose:

It is important that you do not miss any doses. However, if you miss a dose, take it as soon as possible. However, if it is almost time for your next dose, then skip the missed dose. Do not take two doses at once. If you miss several doses in a row, talk to your healthcare professional before restarting your medication.

What are possible side effects from using APO-METHADONE?

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

Side effects with APO-METHADONE may include:

• Drowsiness
• Insomnia
• Dizziness
• Fainting
• Lightheadedness
• Nausea, vomiting, poor appetite
• Dry mouth
• Headache
• Problems with vision
• Weakness, uncoordinated muscle movement
• Itching
• Sweating, facial flushing
• Constipation. Talk with your healthcare professional about ways to prevent constipation when you start using APO-METHADONE.
• Low sex drive, impotence (erectile dysfunction), infertility

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 at 15°C - 30°C. Keep tightly closed. Protect from light.
• Keep unused or expired APO-METHADONE in a secure place to prevent theft, misuse or accidental exposure. It should be kept 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 APO-METHADONE, get emergency help right away.
• APO-METHADONE 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 APO-METHADONE:

• Talk to your healthcare professional.
• Find the full product monograph that is prepared for healthcare professionals and includes this Patient Medication Information by visiting the Health Canada website: (https://www.canada.ca/en/health-canada/services/drugs-health-products/drug-products/drug-product-database.html); the manufacturer’s website (http://www.apotex.ca/products), or by calling 1-800-667-4708.

Last Revised: 2026-01-07