Metadon Nordic Drugs (Methadone)
Synthetic opioid agonist for opioid dependence treatment
Quick facts about Metadon Nordic Drugs
Key takeaways about Metadon Nordic Drugs
- Prescription only: Metadon Nordic Drugs must be prescribed and supervised by physicians experienced in opioid dependence treatment
- Long-acting opioid: The 24–36 hour half-life allows once-daily dosing, providing stable plasma levels throughout the day
- Serious interactions: Must not be combined with MAO inhibitors; benzodiazepines and alcohol increase the risk of life-threatening respiratory depression
- Not for children: Methadone must never be given to children due to severe risk of poisoning even at low doses
- QT prolongation risk: Methadone can affect heart rhythm, especially at higher doses — cardiac monitoring may be required
What Is Metadon Nordic Drugs and What Is It Used For?
Metadon Nordic Drugs is a synthetic opioid medication containing methadone hydrochloride. It is primarily used in opioid agonist therapy (OAT) to treat patients who have developed dependence on opioids such as heroin, morphine, or prescription painkillers. Methadone reduces withdrawal symptoms and drug cravings, enabling patients to participate in rehabilitation.
Methadone belongs to the class of synthetic opioid agonists. It was first developed in Germany during the 1930s and has been used in the treatment of opioid dependence since the 1960s. Today, it is included on the World Health Organization's (WHO) Model List of Essential Medicines and remains one of the most widely studied and prescribed medications for opioid use disorder worldwide.
The medication works by binding to mu-opioid receptors in the brain, the same receptors targeted by heroin and other opioids. However, methadone's unique pharmacological profile — particularly its long half-life of 24 to 36 hours — allows it to provide sustained relief from withdrawal symptoms and cravings without producing the intense euphoria associated with short-acting opioids. This makes it possible for patients to function normally in daily life while undergoing treatment.
Treatment with Metadon Nordic Drugs is always part of a comprehensive programme that includes medical monitoring, psychological counselling, and social rehabilitation. The goal is not merely to substitute one opioid for another, but to stabilise the patient, reduce the harms associated with illicit drug use (such as overdose, infections, and criminal behaviour), and support long-term recovery. Research consistently shows that methadone maintenance therapy significantly reduces illicit opioid use, overdose deaths, HIV transmission, and criminal activity.
Methadone must only be taken by mouth (orally). Under no circumstances should this medication be injected, as injection can cause severe, permanent tissue damage and may be fatal. The oral solution formulation used in many treatment programmes is specifically designed to discourage injection use.
How does methadone work in the body?
Methadone is well absorbed from the gastrointestinal tract, with an oral bioavailability of approximately 80%. After ingestion, peak plasma concentrations are reached within 2 to 4 hours. The drug is extensively metabolised in the liver, primarily by the cytochrome P450 enzymes CYP3A4 and CYP2B6. This extensive hepatic metabolism is the basis for many of methadone's drug interactions, as medications that induce or inhibit these enzymes can significantly alter methadone levels.
One of methadone's most clinically important features is its long elimination half-life, which ranges from 24 to 36 hours (and can be even longer in some patients). This long half-life is what enables once-daily dosing during maintenance therapy. However, it also means that methadone accumulates in the body over several days when treatment is initiated, which is why dose increases must be made slowly and carefully to avoid potentially fatal respiratory depression.
What Should You Know Before Taking Metadon Nordic Drugs?
Before starting methadone treatment, your doctor must be informed about all existing medical conditions, other medications, pregnancy status, and history of substance use. There are absolute contraindications (situations where methadone must not be used) and relative precautions that require careful monitoring.
Contraindications
You must not take Metadon Nordic Drugs if any of the following apply to you:
- Allergy to methadone hydrochloride or any of the other ingredients in the medication
- Current or recent use of MAO inhibitors (monoamine oxidase inhibitors, used for depression and Parkinson's disease) within the last two weeks — the combination can trigger a life-threatening reaction
- Severe respiratory insufficiency — methadone depresses breathing and can be fatal in patients with existing breathing difficulties
Metadon Nordic Drugs must never be given to children. Children are far more sensitive to methadone than adults, and even small doses can cause fatal poisoning. Always store methadone in a secure location completely out of reach of children.
Warnings and Precautions
Tell your doctor or pharmacist before taking Metadon Nordic Drugs if you have any of the following conditions, as additional monitoring or dose adjustments may be needed:
- Acute asthma attacks or chronic obstructive pulmonary disease (COPD)
- Liver or kidney problems, including gallstones or kidney stones
- Heart problems or a history of QT prolongation
- Underactive thyroid (hypothyroidism)
- Enlarged prostate or narrowing of the urethra
- Head injury or raised intracranial pressure
- Low oxygen levels (hypoxemia) or high carbon dioxide levels (hypercapnia) in the blood
- Abdominal pain, diarrhoea, or constipation
- Difficulty urinating
Tolerance, dependence, and risk of misuse
As an opioid medication, repeated use of methadone can lead to tolerance (where higher doses are needed for the same effect) and physical dependence. While methadone maintenance therapy is itself a treatment for opioid dependence, the risk of misuse still exists and is higher in individuals with a personal or family history of substance use disorders, those who smoke, or those with a history of mental health conditions such as depression, anxiety, or personality disorders.
Signs that may indicate problematic use include: needing the medication for longer than prescribed, taking more than the recommended dose, using it for reasons other than those prescribed (such as to "keep calm" or "help sleep"), repeated failed attempts to reduce or stop use, and feeling unwell when stopping (withdrawal symptoms) that improve when the medication is resumed. If you notice any of these signs, discuss them with your doctor.
Sleep-related breathing disorders
Methadone can cause sleep-related breathing disorders including sleep apnoea (pauses in breathing during sleep) and sleep-related hypoxaemia (low blood oxygen during sleep). Symptoms may include breathing pauses noticed by a bed partner, waking at night due to shortness of breath, difficulty maintaining sleep, or excessive daytime sleepiness. If you or someone else observes these symptoms, contact your doctor, who may consider adjusting the dose.
Effects on the heart
Methadone can affect the electrical signals that control the heart's contractions, a condition known as QT prolongation. This effect is dose-dependent and more likely at higher doses. QT prolongation can lead to serious, potentially fatal heart rhythm disturbances (arrhythmias). Your doctor may monitor your heart with an electrocardiogram (ECG) at the start of treatment and periodically during therapy, especially if you have a history of heart problems or are taking other medications that can prolong the QT interval.
Effects on hormones
Long-term methadone use can affect the adrenal glands, potentially causing adrenal insufficiency with symptoms such as weakness, fatigue, loss of appetite, nausea, vomiting, and low blood pressure. It can also reduce levels of sex hormones and increase prolactin levels, which may lead to decreased libido, erectile dysfunction, or missed menstrual periods. Contact your doctor if you experience any of these symptoms.
Pregnancy and Breastfeeding
If you are pregnant, think you may be pregnant, or are planning to have a baby, consult your doctor before using Metadon Nordic Drugs. Methadone should not be used during labour. The decision about continuing methadone during pregnancy requires careful weighing of risks and benefits by an experienced specialist, as untreated opioid dependence during pregnancy also carries significant risks for both mother and baby.
If you are breastfeeding or planning to breastfeed while taking methadone, discuss this with your doctor. Methadone passes into breast milk. If your doctor decides breastfeeding is appropriate during treatment, closely monitor your infant for unusual signs such as increased drowsiness, breathing difficulties, or limpness, and contact your doctor immediately if you notice any of these symptoms.
Driving and operating machinery
Methadone affects coordination between the brain and body movements. Your ability to drive or operate machinery may be severely impaired, particularly during the initial phase of treatment or when doses are being adjusted. Do not drive or operate machinery until your treatment has been stabilised at a consistent dose level and you and your doctor have determined that it is safe to do so. The time required varies considerably between individuals.
How Does Metadon Nordic Drugs Interact with Other Drugs?
Methadone has significant interactions with a wide range of medications. Some combinations are potentially life-threatening, while others may reduce methadone's effectiveness or trigger withdrawal symptoms. Always inform your doctor about all medications, supplements, and herbal products you are using.
Methadone is primarily metabolised by the liver enzymes CYP3A4 and CYP2B6. Medications that inhibit these enzymes can increase methadone levels (raising the risk of side effects), while medications that induce these enzymes can decrease methadone levels (potentially triggering withdrawal). Additionally, combining methadone with other central nervous system depressants or drugs that prolong the QT interval increases the risk of serious adverse effects.
Major Interactions (Avoid or Use with Extreme Caution)
| Drug / Class | Effect | Risk | Action |
|---|---|---|---|
| MAO inhibitors | Unpredictable potentiation of opioid effects | Life-threatening | Contraindicated — do not use within 14 days |
| Benzodiazepines (e.g. diazepam, alprazolam) | Additive CNS and respiratory depression | Life-threatening | Avoid if possible; use lowest effective doses |
| Alcohol | Enhanced sedation and respiratory depression | Life-threatening | Absolutely avoid alcohol during treatment |
| Rifampicin | Strongly induces CYP3A4; dramatically reduces methadone levels | Withdrawal symptoms | Dose increase may be needed; close monitoring |
| Carbamazepine, Phenytoin, Phenobarbital | Induces liver enzymes; reduces methadone levels | Withdrawal symptoms | Monitor and adjust dose as needed |
| St. John's Wort | Induces CYP3A4; reduces methadone levels | Withdrawal symptoms | Avoid combination |
| Naltrexone, Naloxone | Opioid antagonists that block methadone's effects | Precipitated withdrawal | Do not combine without medical supervision |
| Gabapentin, Pregabalin | Increased risk of opioid overdose and respiratory depression | Life-threatening | Use with extreme caution; monitor closely |
Other Notable Interactions
| Drug / Class | Effect | Action |
|---|---|---|
| SSRIs (fluoxetine, fluvoxamine, paroxetine, sertraline) | Increased methadone levels; risk of serotonin syndrome | Monitor for serotonin syndrome symptoms |
| SNRIs (venlafaxin, duloxetine) | Risk of serotonin syndrome | Watch for agitation, hallucinations, rapid heart rate |
| Tricyclic antidepressants (amitriptyline, imipramin) | Increased methadone levels; QT prolongation | ECG monitoring recommended |
| Antiretrovirals (ritonavir, efavirenz, nevirapine) | Complex interactions; may increase or decrease methadone levels | Close monitoring; dose adjustments often needed |
| Macrolide antibiotics (clarithromycin, erythromycin) | Inhibit CYP3A4; may increase methadone levels | Monitor for increased side effects |
| Antifungals (ketoconazole, itraconazole, fluconazole) | Inhibit CYP3A4; may increase methadone levels | Monitor and consider dose reduction |
| Grapefruit juice | Inhibits CYP3A4; may alter methadone effect | Avoid grapefruit juice during treatment |
| Cannabidiol (CBD) | May affect methadone metabolism | Inform doctor if using CBD products |
Using methadone together with certain antidepressants (SSRIs, SNRIs, tricyclics) can cause serotonin syndrome, a potentially dangerous condition. Seek immediate medical attention if you experience agitation, hallucinations, rapid heart rate, unstable blood pressure, fever, excessive sweating, muscle rigidity, poor coordination, nausea, vomiting, or diarrhoea.
What Is the Correct Dosage of Metadon Nordic Drugs?
Methadone dosage is highly individualised and must be determined by your doctor. The usual starting dose for adults is 10–30 mg per day, gradually increased until withdrawal symptoms are controlled without signs of intoxication. Maintenance doses typically range from 60–120 mg per day. Never adjust your dose without medical guidance.
Always take this medicine exactly as your doctor has told you. Do not take more than the agreed dose. Metadon Nordic Drugs must only be taken by mouth. Under no circumstances should it be injected, as this can cause severe permanent damage and may be fatal.
Adults
Standard Adult Dosing
Starting dose: 10–30 mg per day. Treatment is typically initiated at the lower end of this range to minimise the risk of overdose, as tolerance levels are difficult to assess accurately.
Titration: The dose is increased gradually (usually by 5–10 mg every few days) until the patient shows no signs of withdrawal or intoxication.
Maintenance dose: 60–120 mg per day. Research shows that doses in this range are associated with the best outcomes, including reduced illicit opioid use and improved treatment retention.
Administration: Usually given once daily, owing to methadone's long half-life. In supervised treatment programmes, the oral solution is commonly used to ensure compliance.
Elderly and Patients with Organ Impairment
Adjusted Dosing
Elderly patients and those with liver or kidney disease require extra caution. Methadone clearance may be reduced, leading to drug accumulation and an increased risk of side effects. Lower starting doses and slower dose escalation are typically recommended. Regular monitoring of renal and hepatic function is advisable.
Children
Metadon Nordic Drugs must never be given to children. Children are considerably more sensitive to methadone than adults, and poisoning can occur at very low doses. Even accidental ingestion of a small amount can be fatal. Store the medication securely, completely out of reach and sight of children.
Missed Dose
If you miss a dose during a treatment course, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and take the next dose at the usual time. Do not take a double dose to make up for a missed dose.
Overdose
If you or someone else has taken too much methadone, or if a child has accidentally ingested any amount, seek emergency medical help immediately — even if the person appears well, as methadone poisoning can be delayed due to the drug's long half-life.
Symptoms of methadone overdose include:
- Severe breathing difficulties or respiratory arrest
- Extreme drowsiness, loss of consciousness, or coma
- Low blood sugar (hypoglycaemia)
- Pinpoint (constricted) pupils
- Muscle weakness and limpness
- Cool, clammy skin
- Slow heart rate, dangerously low blood pressure
- Cardiac arrest or shock
- Toxic leukoencephalopathy (a brain condition) in severe cases
What Are the Side Effects of Metadon Nordic Drugs?
Like all medicines, Metadon Nordic Drugs can cause side effects, though not everyone experiences them. The most common side effect is nausea or vomiting. Many side effects are dose-dependent and tend to decrease as the body adjusts to the medication over time.
Side effects are classified below by how frequently they occur. If you experience any side effects that are severe, persistent, or concerning, contact your doctor or pharmacist. This is particularly important for symptoms affecting your breathing, heart rhythm, or level of consciousness.
Very Common
- Nausea or vomiting
Common
- Weight gain
- Fluid retention (oedema)
- Constipation
- Euphoria
- Hallucinations (seeing or hearing things that are not real)
- Dizziness or a spinning sensation (vertigo)
- Blurred vision
- Pinpoint pupils (miosis)
- Drowsiness
- Skin rash
- Excessive sweating
- Fatigue
Uncommon
- Loss of appetite
- Breathing difficulties (including cough)
- Dry mouth
- Inflammation of the tongue
- Dysphoria (feeling of unease or dissatisfaction)
- Restlessness or agitation
- Insomnia
- Confusion
- Decreased sex drive
- Headache
- Fainting (syncope)
- Low blood pressure (hypotension)
- Itching
- Hives (urticaria)
- Swollen legs
- Weakness
- Severe fluid retention
- Biliary spasm (causing abdominal pain)
- Facial flushing
- Difficulty urinating
- Erectile dysfunction
- Menstrual irregularities
Rare
- Heart rhythm abnormalities
- Slow heart rate (bradycardia)
- Palpitations (awareness of heartbeat)
Frequency Not Known
- Low potassium or magnesium levels in the blood
- Reduced platelet count
- Low blood sugar (hypoglycaemia)
- Dependence (see Warnings section above)
- Sleep apnoea (breathing pauses during sleep)
Reporting suspected side effects after a medicine has been authorised is important. It allows continued monitoring of the medicine's benefit-risk balance. You can report side effects to your national medicines regulatory authority.
How Should You Store Metadon Nordic Drugs?
Store methadone out of the sight and reach of children in a secure location where other people cannot access it. Accidental ingestion by non-tolerant individuals, especially children, can cause serious harm or death.
Keep this medicine in a safe, locked location. Methadone is a potent opioid that can cause severe harm or death in people who have not been prescribed it, particularly children. Many treatment programmes dispense the oral solution in single-dose containers to minimise the risk of diversion and accidental exposure.
Do not use this medicine after the expiry date stated on the bottle or carton. The expiry date refers to the last day of the stated month. Do not dispose of medicines via wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer in use. These measures help protect the environment and prevent accidental exposure.
What Does Metadon Nordic Drugs Contain?
The active substance in Metadon Nordic Drugs is methadone hydrochloride. The oral solution is available in a range of strengths from 10 mg to 200 mg per 50 ml dose. Tablets are available in 5 mg and 10 mg strengths.
Oral Solution
Each 50 ml dose of the oral solution contains methadone hydrochloride in strengths ranging from 10 mg to 200 mg. The other ingredients are sucrose, glucose, methylparahydroxybenzoate (E 218), raspberry flavouring, and purified water. The solution is a clear, transparent liquid packaged in a plastic bottle with a child-resistant cap.
Each dose of the oral solution contains approximately 11 g of sucrose and 2.5 g of glucose. This sugar content should be taken into account by patients with diabetes mellitus. The solution may also be harmful to teeth. The preservative methylparahydroxybenzoate (E 218) may cause allergic reactions (possibly delayed).
Tablets
Available in strengths of 5 mg and 10 mg methadone hydrochloride per tablet.
Manufacturer
Metadon Nordic Drugs is manufactured by Apotek Produktion & Laboratorier AB and marketed by Nordic Drugs AB. The medication is approved in the European Economic Area under the name Metadon Nordic Drugs in Sweden, Finland, and Norway.
Frequently Asked Questions About Metadon Nordic Drugs
Metadon Nordic Drugs contains methadone hydrochloride, a synthetic opioid primarily used for opioid agonist therapy (OAT) in patients with opioid dependence. It works by binding to the same brain receptors as heroin and other opioids, but its long duration of action (24–36 hours) provides stable relief from withdrawal symptoms and cravings without the intense highs and lows of short-acting opioids. Treatment is always combined with psychological counselling and social rehabilitation.
The most common side effect is nausea or vomiting, affecting more than 1 in 10 patients. Other common side effects include constipation, sweating, drowsiness, dizziness, weight gain, fluid retention, blurred vision, and fatigue. Many of these effects are dose-dependent and tend to improve as the body adjusts to the medication. Serious but less common effects include breathing difficulties, heart rhythm changes, and low blood pressure.
Yes, methadone overdose can be life-threatening and requires immediate emergency medical treatment. Because of methadone's long half-life, toxicity can be delayed — a person may appear well initially but deteriorate hours later. Symptoms include severe breathing difficulties, extreme drowsiness or coma, pinpoint pupils, cold clammy skin, slow heart rate, and dangerously low blood pressure. Always call emergency services if overdose is suspected.
MAO inhibitors are absolutely contraindicated with methadone. Benzodiazepines, alcohol, and other sedatives dramatically increase the risk of fatal respiratory depression. Enzyme-inducing drugs like rifampicin, carbamazepine, phenytoin, and St. John's Wort can reduce methadone levels and precipitate withdrawal. Certain antidepressants may cause serotonin syndrome. Gabapentin and pregabalin increase the risk of overdose. Always give your doctor a complete list of all medications and supplements you use.
The use of methadone during pregnancy is a complex clinical decision that must be made by a specialist. While methadone can affect the developing baby, untreated opioid dependence poses even greater risks including premature birth, low birth weight, and maternal overdose. Methadone maintenance is generally considered safer than continued illicit opioid use during pregnancy. Neonatal abstinence syndrome (withdrawal symptoms in the newborn) may occur and requires monitoring. Methadone should not be used during labour.
Treatment duration is highly individual and depends on clinical assessment. Many patients benefit from long-term methadone maintenance, sometimes lasting years, as research consistently shows that longer treatment duration is associated with better outcomes and lower relapse rates. Any dose reduction or discontinuation should be done very gradually under medical supervision, as abrupt stopping can cause severe withdrawal symptoms and increases the risk of relapse and overdose.
References
All medical information on this page is based on peer-reviewed research, international guidelines, and established clinical evidence. The following sources were used:
- World Health Organization (WHO). Guidelines for the Psychosocially Assisted Pharmacological Treatment of Opioid Dependence. Geneva: WHO; 2009. Updated 2023.
- European Medicines Agency (EMA). Summary of Product Characteristics: Methadone. EMA Assessment Reports.
- Mattick RP, Breen C, Kimber J, Davoli M. Methadone maintenance therapy versus no opioid replacement therapy for opioid dependence. Cochrane Database of Systematic Reviews. 2009;(3):CD002209. Updated 2024.
- U.S. Food and Drug Administration (FDA). Methadone Hydrochloride Prescribing Information. FDA Drug Safety Communications.
- British National Formulary (BNF). Methadone Hydrochloride Monograph. National Institute for Health and Care Excellence (NICE).
- Chou R, Korthuis PT, McCarty D, et al. Management of Suspected Opioid Overdose With Naloxone in Out-of-Hospital Settings: A Systematic Review. Annals of Internal Medicine. 2017;167(12):867-875.
- Kreek MJ. Methadone-related opioid agonist pharmacotherapy for heroin addiction: history, recent molecular and neurochemical research and the future in mainstream medicine. Annals of the New York Academy of Sciences. 2000;909:186-216.
- Eap CB, Buclin T, Baumann P. Interindividual variability of the clinical pharmacokinetics of methadone: implications for the treatment of opioid dependence. Clinical Pharmacokinetics. 2002;41(14):1153-1193.
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This article has been written and reviewed by iMedic's medical editorial team, which consists of licensed physicians with specialist training in pharmacology and addiction medicine.
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