Description and Brand Names

Drug information provided by: Merative, Micromedex®

Descriptions


Methadone injection is used to relieve severe and persistent pain that requires daily opioid treatment and when other pain medicines did not work well enough or cannot be tolerated. This medicine should not be used to treat pain that you only have once in a while or "as needed". Methadone injection is also used together with medical supervision and counseling to treat opioid addiction (eg, heroin or other morphine-like drugs) in patients who cannot take oral medicines.

Methadone is an opioid (narcotic) analgesic (pain medicine). It acts on the nervous system to relieve pain.

This medicine is to be given only by or under the direct supervision of a doctor.

This product is available in the following dosage forms:

  • Solution

Before Using

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies have not been performed on the relationship of age to the effects of methadone injection in the pediatric population. Safety and efficacy have not been established.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of methadone injection in the elderly. However, elderly patients are more likely to have age-related heart, kidney, liver, or lung problems, which may require caution and an adjustment in the dose for patients receiving methadone injection.

Breastfeeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Drug Interactions

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are receiving this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

  • Bepridil
  • Cisapride
  • Dronedarone
  • Fluconazole
  • Itraconazole
  • Ketoconazole
  • Levoketoconazole
  • Mesoridazine
  • Nalmefene
  • Naltrexone
  • Nelfinavir
  • Pimozide
  • Piperaquine
  • Posaconazole
  • Rasagiline
  • Safinamide
  • Samidorphan
  • Saquinavir
  • Sparfloxacin
  • Terfenadine
  • Thioridazine
  • Ziprasidone

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Abametapir
  • Acepromazine
  • Adagrasib
  • Alfentanil
  • Alfuzosin
  • Almotriptan
  • Alprazolam
  • Amineptine
  • Amiodarone
  • Amisulpride
  • Amitriptyline
  • Amitriptylinoxide
  • Amobarbital
  • Amoxapine
  • Amphetamine
  • Amprenavir
  • Anagrelide
  • Anileridine
  • Apomorphine
  • Aprepitant
  • Aripiprazole
  • Aripiprazole Lauroxil
  • Armodafinil
  • Arsenic Trioxide
  • Artemether
  • Asenapine
  • Astemizole
  • Azithromycin
  • Baclofen
  • Bedaquiline
  • Benperidol
  • Benzhydrocodone
  • Benzphetamine
  • Boceprevir
  • Bosentan
  • Bromazepam
  • Bromopride
  • Brompheniramine
  • Buprenorphine
  • Bupropion
  • Buserelin
  • Buspirone
  • Butabarbital
  • Butorphanol
  • Calcium Oxybate
  • Cannabidiol
  • Cannabis
  • Capecitabine
  • Carbamazepine
  • Carbinoxamine
  • Cariprazine
  • Carisoprodol
  • Carphenazine
  • Ceritinib
  • Cetirizine
  • Chloral Hydrate
  • Chlordiazepoxide
  • Chloroquine
  • Chlorpheniramine
  • Chlorpromazine
  • Chlorzoxazone
  • Ciprofloxacin
  • Citalopram
  • Clarithromycin
  • Clobazam
  • Clofazimine
  • Clomipramine
  • Clonazepam
  • Clopidogrel
  • Clorazepate
  • Clothiapine
  • Clozapine
  • Cobicistat
  • Cocaine
  • Codeine
  • Conivaptan
  • Crizotinib
  • Cyclobenzaprine
  • Cyclosporine
  • Dabrafenib
  • Dantrolene
  • Daridorexant
  • Darunavir
  • Dasatinib
  • Degarelix
  • Delamanid
  • Delavirdine
  • Desipramine
  • Deslorelin
  • Desmopressin
  • Desvenlafaxine
  • Deutetrabenazine
  • Dexamethasone
  • Dexmedetomidine
  • Dextroamphetamine
  • Dextromethorphan
  • Dezocine
  • Diazepam
  • Dibenzepin
  • Dichloralphenazone
  • Difenoxin
  • Dihydrocodeine
  • Diltiazem
  • Diphenhydramine
  • Diphenoxylate
  • Disopyramide
  • Dofetilide
  • Dolasetron
  • Domperidone
  • Donepezil
  • Doxepin
  • Doxylamine
  • Droperidol
  • Duloxetine
  • Ebastine
  • Eletriptan
  • Encorafenib
  • Enflurane
  • Entrectinib
  • Enzalutamide
  • Eribulin
  • Erythromycin
  • Escitalopram
  • Esketamine
  • Eslicarbazepine Acetate
  • Estazolam
  • Eszopiclone
  • Ethchlorvynol
  • Ethopropazine
  • Ethylmorphine
  • Etrasimod
  • Famotidine
  • Fedratinib
  • Felbamate
  • Fenfluramine
  • Fentanyl
  • Fexinidazole
  • Fingolimod
  • Flecainide
  • Flibanserin
  • Fluoxetine
  • Fluphenazine
  • Flurazepam
  • Fluspirilene
  • Fluvoxamine
  • Formoterol
  • Fosaprepitant
  • Foscarnet
  • Fosnetupitant
  • Fosphenytoin
  • Fospropofol
  • Fostemsavir
  • Frovatriptan
  • Furazolidone
  • Gabapentin
  • Gabapentin Enacarbil
  • Galantamine
  • Gatifloxacin
  • Gemifloxacin
  • Gepirone
  • Glasdegib
  • Gonadorelin
  • Goserelin
  • Granisetron
  • Halazepam
  • Halofantrine
  • Haloperidol
  • Halothane
  • Hexobarbital
  • Histrelin
  • Hydrocodone
  • Hydromorphone
  • Hydroquinidine
  • Hydroxyamphetamine
  • Hydroxychloroquine
  • Hydroxytryptophan
  • Hydroxyzine
  • Ibutilide
  • Idelalisib
  • Iloperidone
  • Imatinib
  • Imipramine
  • Indinavir
  • Inotuzumab Ozogamicin
  • Iproniazid
  • Isocarboxazid
  • Isoflurane
  • Ivabradine
  • Ivacaftor
  • Ivosidenib
  • Ketamine
  • Ketazolam
  • Ketobemidone
  • Lacosamide
  • Lapatinib
  • Lasmiditan
  • Lefamulin
  • Lemborexant
  • Lenacapavir
  • Lenvatinib
  • Leuprolide
  • Levocetirizine
  • Levofloxacin
  • Levomilnacipran
  • Levorphanol
  • Linezolid
  • Lisdexamfetamine
  • Lithium
  • Lofepramine
  • Lofexidine
  • Lomitapide
  • Lopinavir
  • Lorazepam
  • Lorcaserin
  • Loxapine
  • Lumacaftor
  • Lumefantrine
  • Lurasidone
  • Macimorelin
  • Magnesium Oxybate
  • Mavacamten
  • Meclizine
  • Mefloquine
  • Melitracen
  • Melperone
  • Meperidine
  • Mephobarbital
  • Meprobamate
  • Meptazinol
  • Metaxalone
  • Methamphetamine
  • Methdilazine
  • Methocarbamol
  • Methohexital
  • Methotrimeprazine
  • Methylene Blue
  • Metoclopramide
  • Metronidazole
  • Mibefradil
  • Midazolam
  • Mifepristone
  • Milnacipran
  • Mirtazapine
  • Mitotane
  • Mizolastine
  • Mobocertinib
  • Moclobemide
  • Modafinil
  • Molindone
  • Moricizine
  • Morphine
  • Morphine Sulfate Liposome
  • Moxifloxacin
  • Nafarelin
  • Nafcillin
  • Nalbuphine
  • Naratriptan
  • Nefazodone
  • Netupitant
  • Nialamide
  • Nicomorphine
  • Nilotinib
  • Nirmatrelvir
  • Nitrazepam
  • Nitrous Oxide
  • Norfloxacin
  • Nortriptyline
  • Octreotide
  • Ofloxacin
  • Olanzapine
  • Oliceridine
  • Omaveloxolone
  • Ondansetron
  • Opipramol
  • Opium
  • Opium Alkaloids
  • Orphenadrine
  • Osilodrostat
  • Osimertinib
  • Oxaliplatin
  • Oxazepam
  • Oxcarbazepine
  • Oxycodone
  • Oxymorphone
  • Ozanimod
  • Pacritinib
  • Palbociclib
  • Paliperidone
  • Palonosetron
  • Panobinostat
  • Papaveretum
  • Papaverine
  • Paregoric
  • Paroxetine
  • Pasireotide
  • Pazopanib
  • Peginterferon Alfa-2b
  • Pentamidine
  • Pentazocine
  • Pentobarbital
  • Perampanel
  • Perazine
  • Periciazine
  • Perphenazine
  • Phenelzine
  • Phenobarbital
  • Phenytoin
  • Pimavanserin
  • Pipamperone
  • Piperacetazine
  • Pipotiazine
  • Piritramide
  • Pitolisant
  • Ponesimod
  • Potassium Oxybate
  • Prazepam
  • Prednisone
  • Pregabalin
  • Primidone
  • Probucol
  • Procainamide
  • Procarbazine
  • Prochlorperazine
  • Promazine
  • Promethazine
  • Propafenone
  • Propofol
  • Protriptyline
  • Quazepam
  • Quetiapine
  • Quinidine
  • Quinine
  • Quizartinib
  • Ramelteon
  • Ranitidine
  • Ranolazine
  • Relugolix
  • Remifentanil
  • Remimazolam
  • Remoxipride
  • Ribociclib
  • Rifabutin
  • Rifampin
  • Rifapentine
  • Ritonavir
  • Rizatriptan
  • Ropeginterferon Alfa-2b-njft
  • Scopolamine
  • Secobarbital
  • Selegiline
  • Selpercatinib
  • Sertindole
  • Sertraline
  • Sevoflurane
  • Sibutramine
  • Siponimod
  • Sodium Oxybate
  • Sodium Phosphate
  • Sodium Phosphate, Dibasic
  • Sodium Phosphate, Monobasic
  • Solifenacin
  • Sorafenib
  • Sotalol
  • Sparsentan
  • St John's Wort
  • Sufentanil
  • Sulpiride
  • Sunitinib
  • Suvorexant
  • Tacrolimus
  • Tamoxifen
  • Tapentadol
  • Telaprevir
  • Telavancin
  • Telithromycin
  • Temazepam
  • Tetrabenazine
  • Thiethylperazine
  • Thiopental
  • Thiopropazate
  • Thiothixene
  • Tianeptine
  • Tilidine
  • Tipranavir
  • Tizanidine
  • Tolonium Chloride
  • Topiramate
  • Toremifene
  • Tramadol
  • Tranylcypromine
  • Trazodone
  • Triazolam
  • Triclabendazole
  • Trifluoperazine
  • Trifluperidol
  • Triflupromazine
  • Trimeprazine
  • Trimipramine
  • Triptorelin
  • Tryptophan
  • Vandetanib
  • Vardenafil
  • Vemurafenib
  • Venlafaxine
  • Verapamil
  • Vilanterol
  • Vilazodone
  • Vinflunine
  • Voclosporin
  • Voriconazole
  • Vorinostat
  • Vortioxetine
  • Zaleplon
  • Zolmitriptan
  • Zolpidem
  • Zopiclone
  • Zotepine
  • Zuclopenthixol
  • Zuranolone

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Abacavir
  • Atazanavir
  • Didanosine
  • Etravirine
  • Fosamprenavir
  • Nevirapine
  • Peginterferon Alfa-2a
  • Stavudine
  • Zidovudine

Other Interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following may cause an increased risk of certain side effects but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Alcohol abuse, or history of or
  • Brain tumor or
  • Breathing or lung problems (eg, COPD, cor pulmonale, hypercapnia, hypoxia, apnea, sleep apnea) or
  • Depression, history of or
  • Drug dependence, especially narcotic abuse or dependence, history of or
  • Gallbladder disease or
  • Head injuries, history of or
  • Heart disease (eg, cardiac hypertrophy) or
  • Heart rhythm problems (eg, arrhythmia, long QT syndrome), or history of or
  • Hypokalemia (low potassium in the blood) or
  • Hypomagnesemia (low magnesium in the blood) or
  • Increased pressure in your head or
  • Stomach or bowel problems or
  • Weakened physical condition—Use with caution. May increase risk for more serious side effects.
  • Asthma, acute or severe or
  • Respiratory depression (serious breathing problem) or
  • Stomach or bowel blockage (including paralytic ileus), known or suspected—Should not be used in patients with these conditions.
  • Hypotension (low blood pressure) or
  • Pancreatitis (inflammation of the pancreas) or
  • Seizures, history of—Use with caution. May make these conditions worse.
  • Kidney disease or
  • Liver disease—Use with caution. The effects may be increased because of slower removal of the medicine from the body.

Proper Use

A doctor or other trained health professional will give you this medicine in a medical facility. This medicine is given as a shot under your skin or into a muscle or a vein.

Precautions

It is very important that your doctor check your progress while you are using this medicine. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to receive it.

Do not use this medicine if you are using or have used an MAO inhibitor within the past 14 days.

This medicine may cause serious allergic reactions, including anaphylaxis, which can be life-threatening and require immediate medical attention. Call your doctor right away if you have a rash, itching, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth while you are using this medicine.

This medicine will add to the effects of alcohol and other central nervous system (CNS) depressants. CNS depressants are medicines that slow down the nervous system, which may cause drowsiness or make you less alert. Some examples of CNS depressants are antihistamines or medicine for allergies or colds, sedatives, tranquilizers, or sleeping medicine, other prescription pain medicine or narcotics, medicine for anxiety or benzodiazepines, medicine for seizures or barbiturates, muscle relaxants, or anesthetics (numbing medicines), including some dental anesthetics. This effect may last for a few days after you stop using this medicine. Check with your doctor before taking any of the other medicines listed above while you are using this medicine.

Do not use more of this medicine or use it more often than your doctor tells you to. This can be life-threatening. Symptoms of an overdose include extreme dizziness or weakness, trouble breathing, slow heartbeat, seizures, and cold, clammy skin. Call your doctor right away if you notice these symptoms.

This medicine may cause sleep-related breathing problems (eg, sleep apnea, sleep-related hypoxemia). Your doctor may decrease your dose if you have sleep apnea (stop breathing for short periods during sleep) while using this medicine.

Contact your doctor right away if you have any changes to your heart rhythm. You might feel dizzy or faint, or you might have a fast, pounding, or uneven heartbeat. Make sure your doctor knows if you or anyone in your family has ever had a heart rhythm problem such as QT prolongation.

Using this medicine while you are pregnant may cause neonatal withdrawal syndrome in your newborn child. Tell your doctor right away if your baby has an abnormal sleep pattern, diarrhea, a high-pitched cry, irritability, shakiness or tremors, weight loss, vomiting, or fails to gain weight.

Call your doctor right away if you have worsening of pain, increased sensitivity to pain, or new pain after taking this medicine. These may be symptoms of opioid-induced hyperalgesia and allodynia.

Check with your doctor right away if you have anxiety, restlessness, a fast heartbeat, fever, sweating, muscle spasms, twitching, nausea, vomiting, diarrhea, or see or hear things that are not there. These may be symptoms of a serious condition called serotonin syndrome. Your risk may be higher if you also take certain other medicines that affect serotonin levels in your body.

This medicine may cause adrenal gland problems. Check with your doctor right away if you have darkening of the skin, diarrhea, dizziness, fainting, loss of appetite, mental depression, nausea, skin rash, unusual tiredness or weakness, or vomiting.

This medicine may be habit-forming (causing mental or physical dependence). If you feel that the medicine is not working as well, do not use more than your prescribed dose. Call your doctor for instructions.

Using narcotics for a long time can cause severe constipation. To prevent this, your doctor may direct you to take laxatives, drink a lot of fluids, or increase the amount of fiber in your diet. Be sure to follow the directions carefully, because continuing constipation can lead to more serious problems.

If you have been using this medicine regularly for several weeks or more, do not suddenly stop using it without first checking with your doctor. You may be directed to gradually reduce the amount you are using before stopping treatment completely, or to take another narcotic for a while, to lessen the chance of withdrawal side effects.

Dizziness, lightheadedness, or fainting may occur when you get up suddenly from a lying or sitting position. Getting up slowly may help lessen this problem. Also, lying down for a while may relieve dizziness or lightheadedness.

This medicine may make you dizzy, drowsy, or lightheaded. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous until you know how this medicine affects you.

Before you have any medical tests, tell the medical doctor in charge that you are using this medicine. The results of some tests may be affected by this medicine.

Using too much of this medicine may cause infertility (unable to have children). Talk with your doctor before using this medicine if you plan to have children.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (eg, St. John's wort) or vitamin supplements.

Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

Incidence not known

  1. Agitation
  2. blurred vision
  3. confusion
  4. darkening of the skin
  5. diarrhea
  6. difficult or troubled breathing
  7. dizziness
  8. dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  9. fainting
  10. fever
  11. increased sensitivity to pain
  12. irregular heartbeat
  13. recurrent irregular, fast or slow, or shallow breathing
  14. loss of appetite
  15. mental depression
  16. nausea
  17. overactive reflexes
  18. pale or blue lips, fingernails, or skin
  19. poor coordination
  20. restlessness
  21. seizures
  22. shivering
  23. skin rash
  24. sweating
  25. talking or acting with excitement you cannot control
  26. trembling or shaking
  27. twitching
  28. unusual tiredness or weakness
  29. vomiting
  30. worsening of pain

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known

  1. Bleeding, blistering, burning, coldness, discoloration of the kin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site
  2. difficulty having a bowel movement (stool)
  3. dry mouth
  4. headache
  5. lack or loss of strength
  6. loss of appetite
  7. weight loss

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.