1. Methadone Hydrochloride Injection is indicated for the management of severe and persistent pain that requires an opioid analgesic and that cannot be adequately treated with alternative options, including immediate-release opioids. Limitations of Use
Because of the risks of addiction, abuse, misuse, overdose, and death, which can occur at any dosage or duration (see WARNINGS ), and persist over the course of therapy, reserve opioid analgesics, including Methadone Hydrochloride Injection, for use in patients for whom alternative treatment options are ineffective, not tolerated, or would be otherwise inadequate to provide sufficient management of pain.
Methadone Hydrochloride Injection is not indicated as an as-needed (prn) analgesic. 2. For use in temporary treatment of opioid dependence in patients unable to take oral medication. Limitations of Use
Injectable methadone products are not approved for the outpatient treatment of opioid dependence. In this patient population, parenteral methadone is to be used only for patients unable to take oral medication, such as hospitalized patients. Conditions for Distribution and Use of Methadone Products for the Treatment of Opioid Addiction Code of Federal Regulations, Title 42, Sec 8. Methadone products when used for the treatment of opioid addiction in detoxification or maintenance programs, shall be dispensed only by opioid treatment programs (and agencies, practitioners or institutions by formal agreement with the program sponsor) certified by the Substance Abuse and Mental Health Services Administration and approved by the designated state authority. Certified treatment programs shall dispense and use methadone in oral form only and according to the treatment requirements stipulated in the Federal Opioid Treatment Standards (42 CFR 8.12). See below for important regulatory exceptions to the general requirement for certification to provide opioid agonist treatment. Failure to abide by the requirements in these regulations may result in criminal prosecution, seizure of the drug supply, revocation of the program approval, and injunction precluding operation of the program. Regulatory Exceptions to the General Requirement for Certification to Provide Opioid Agonist Treatment: During inpatient care, when the patient was admitted for any condition other than concurrent opioid addiction (pursuant to 21CFR 1306.07(c)), to facilitate the treatment of the primary admitting diagnosis. During an emergency period of no longer than 3 days while definitive care for the addiction is being sought in an appropriately licensed facility (pursuant to 21CFR 1306.07(b)).
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Methadone Hydrochloride Injection is contraindicated in patients with:
Significant respiratory depression
Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment
Known or suspected gastrointestinal obstruction, including paralytic ileus
Hypersensitivity to methadone hydrochloride (e.g. anaphylaxis) or any other ingredient in Methadone Hydrochloride Injection.
Warnings and precautions
Addiction, Abuse and Misuse Methadone Hydrochloride Injection contains methadone, a Schedule II controlled substance. As an opioid, Methadone Hydrochloride Injection exposes users to the risks of addiction, abuse, and misuse. Although the risk of addiction in any individual is unknown, it can occur in patients appropriately prescribed Methadone Hydrochloride Injection. Addiction can occur at recommended doses and if the drug is misused or abused.
The risk of opioid-related overdose or overdose-related death is increased with higher opioid doses, and this risk persists over the course of therapy. In postmarketing studies, addiction, abuse, misuse, and fatal and non-fatal opioid overdose were observed in patients with long-term opioid use (see ADVERSE REACTIONS ; Postmarketing Experience). Assess each patient’s risk for opioid addiction, abuse, or misuse prior to prescribing Methadone Hydrochloride Injection, and reassess all patients receiving Methadone Hydrochloride Injection for the development of these behaviors and conditions.
Risks are increased in patients with a personal or family history of substance abuse (including drug or alcohol addiction or abuse) or mental illness (e.g., major depression). The potential for these risks should not, however, prevent the prescribing of Methadone Hydrochloride Injection for the proper management of pain in any given patient. Opioids are sought for nonmedical use and are subject to diversion from legitimate prescribed use.
Consider these risks when prescribing or dispensing Methadone Hydrochloride Injection. Strategies to reduce these risks include proper product storage and control practices for a C-II drug. Contact local state professional licensing board or state-controlled substances authority for information on how to prevent and detect abuse or diversion of this product. Life-Threatening Respiratory Depression Serious, life-threatening, or fatal respiratory depression has been reported with the use of opioids, even when used as recommended.
Respiratory depression, if not immediately recognized and treated, may lead to respiratory depression and death. Management of respiratory depression may include close observation, supportive measures, and use of opioid overdose reversal agents (e.g., naloxone, nalmefene), depending on the patient’s clinical status. Carbon dioxide (CO 2 ) retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids.
While serious, life-threatening, or fatal respiratory depression can occur at any time during the use of Methadone Hydrochloride Injection, the risk is greatest during the initiation of therapy or following a dosage increase. To reduce the risk of respiratory depression, proper dosing and titration of Methadone Hydrochloride Injection are essential. Overestimating the Methadone Hydrochloride Injection dosage when converting patients from another opioid product can result in a fatal overdose with the first dose.
Methadone Hydrochloride Injection should be administered with extreme caution to patients with conditions accompanied by hypoxia, hypercapnia, or decreased respiratory reserve such as; asthma, chronic obstructive pulmonary disease or cor pulmonale, severe obesity, sleep apnea syndrome, myxedema, kyphoscoliosis, CNS depression or coma. In these patients even usual therapeutic doses of methadone may decrease respiratory drive while simultaneously increasing airway resistance to the point of apnea.
Alternative non-opioid analgesics should be considered, and methadone should be employed only under careful medical supervision at the lowest effective dose. Methadone's peak respiratory depressant effects typically occur later, and persist longer than its peak analgesic effects, in the short-term use setting. These characteristics can contribute to cases of iatrogenic overdose, particularly during treatment initiation and dose titration.
Opioids can cause sleep-related breathing disorders including central sleep apnea (CSA) and sleep-related hypoxemia. Opioid use increases the risk of CSA in a dose-dependent fashion. In patients who present with CSA, consider decreasing the opioid dosage using best practices for opioid taper (see DOSAGE AND ADMINISTRATION ). Life-Threatening QT Prolongation Cases of QT interval prolongation and serious arrhythmia (torsades de pointes) have been observed during treatment with methadone.
These cases appear to be more commonly associated with, but not limited to, higher dose treatment (> 200 mg/day). Most cases involve patients being treated for pain with large, multiple daily doses of methadone, although cases have been reported in patients receiving doses commonly used for maintenance treatment of opioid addiction. In most patients on the lower doses typically used for maintenance, concomitant medications and/or clinical conditions such as hypokalemia were noted as contributing factors.
However, the evidence strongly suggests that methadone possesses the potential for adverse cardiac conduction effects in some patients. The effects of methadone on the QT interval have been confirmed in in vivo laboratory studies, and methadone has been shown to inhibit cardiac potassium channels in in vitro studies. Closely monitor patients with risk factors for development of prolonged QT interval (e.g., cardiac hypertrophy, concomitant diuretic use, hypokalemia and hypomagnesemia), a history of cardiac conduction abnormalities, and those taking medications affecting cardiac conduction.
QT prolongation has also been reported in patients with no prior cardiac history who have received high doses of methadone. Evaluate patients developing QT prolongation while on methadone treatment for the presence of modifiable risk factors, such as concomitant medications with cardiac effects, drugs that might cause electrolyte abnormalities, and drugs that might act as inhibitors of methadone metabolism. Only initiate methadone hydrochloride tablets therapy for pain in patients for whom the anticipated benefit outweighs the risk of QT prolongation and development of dysrhythmias that have been reported with high doses of methadone.
The use of methadone in patients already known to have a prolonged QT interval has not been systematically studied. Managing Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants Profound sedation, respiratory depression, coma, and death may result from the concomitant use of Methadone Hydrochloride Injection with benzodiazepines and/or other CNS depressants (e.g., alcohol, non-benzodiazepine sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, gabapentinoids [gabapentin or pregabalin], and other opioids).
Because of these risks, reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate. Observational studies have demonstrated that concomitant use of opioid analgesics and benzodiazepines increases the risk of drug-related mortality compared to use of opioid analgesics alone. Because of similar pharmacological properties, it is reasonable to expect similar risk with the concomitant use of other CNS depressant drugs with opioid analgesics (see PRECAUTIONS: Drug Interactions ).
If the decision is made to prescribe a benzodiazepine or other CNS depressant concomitantly with an opioid analgesic, prescribe the lowest effective dosages and minimum durations of concomitant use. In patients already receiving an opioid analgesic, prescribe a lower initial dose of the benzodiazepine or other CNS depressant than indicated in the absence of an opioid, and titrate based on clinical response. If an opioid analgesic is initiated in a patient already taking a benzodiazepine or other CNS depressant, prescribe a lower initial dose of the opioid analgesic, and titrate based on clinical response.
Follow patients closely for signs and symptoms of respiratory depression and sedation. Ne
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Interactions
Drug Interactions Table 1: Clinically Significant Drug Interactions with Methadone Hydrochloride Injection Inhibitors of CYP3A4, CYP2B6, CYP2C19, CYP2C9, or CYP2D6 Clinical Impact: Methadone undergoes hepatic N-demethylation by several cytochrome P450 (CYP) isoforms, including CYP3A4, CYP2B6, CYP2C19, CYP2C9, and CYP2D6. The concomitant use of Methadone Hydrochloride Injection and CYP3A4, CYP2B6, CYP2C19, CYP2C9, or CYP2D6 inhibitors can increase the plasma concentration of methadone, resulting in increased or prolonged opioid effects, and may result in a fatal overdose, particularly when an inhibitor is added after a stable dose of Methadone Hydrochloride Injection is achieved.
These effects may be more pronounced with concomitant use of drugs that inhibit more than one of the CYP enzymes listed above. After stopping a CYP3A4, CYP2B6, CYP2C19, CYP2C9, or CYP2D6 inhibitor, as the effects of the inhibitor decline, the methadone plasma concentration can decrease (see CLINICAL PHARMACOLOGY ), resulting in decreased opioid efficacy or withdrawal symptoms in patients physically dependent on methadone.
Intervention: If concomitant use is necessary, consider dosage reduction of Methadone Hydrochloride Injection until stable drug effects are achieved. Monitor patients for respiratory depression and sedation at frequent intervals. If a CYP3A4, CYP2B6, CYP2C19, CYP2C9, or CYP2D6 inhibitor is discontinued, follow patients for signs of opioid withdrawal and consider increasing the Methadone Hydrochloride Injection dosage until stable drug effects are achieved.
Examples: Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), protease inhibitors (e.g., ritonavir), fluconazole, fluvoxamine, Some selective serotonin reuptake inhibitors (SSRIs) (e.g., sertraline, fluvoxamine) Inducers of CYP3A4, CYP2B6, CYP2C19, or CYP2C9 Clinical Impact: The concomitant use of Methadone Hydrochloride Injection and CYP3A4, CYP2B6, CYP2C19, or CYP2C9 inducers can decrease the plasma concentration of methadone (see CLINICAL PHARMACOLOGY ), resulting in decreased efficacy or onset of withdrawal symptoms in patients physically dependent on methadone.
These effects could be more pronounced with concomitant use of drugs that can induce multiple CYP enzymes. After stopping a CYP3A4, CYP2B6, CYP2C19, or CYP2C9 inducer, as the effects of the inducer decline, the methadone plasma concentration can increase (see CLINICAL PHARMACOLOGY ), which could increase or prolong both the therapeutic effects and adverse reactions, and may cause serious respiratory depression, sedation, or death.
Intervention: If concomitant use is necessary, consider increasing the Methadone Hydrochloride Injection dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal. If a CYP3A4, CYP2B6, CYP2C19, or CYP2C9 inducer is discontinued, consider Methadone Hydrochloride Injection dosage reduction and monitor for signs of respiratory depression and sedation. Examples: Rifampin, carbamazepine, phenytoin, St.
John’s Wort, Phenobarbital Benzodiazepines and other Central Nervous System (CNS) Depressants Clinical Impact: Due to additive pharmacologic effect, the concomitant use of benzodiazepines or other CNS depressants, including alcohol, can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death (see WARNINGS ). Intervention: Reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate.
Limit dosages and durations to the minimum required. Monitor patients closely for signs of respiratory depression and sedation (see WARNINGS , PRECAUTIONS ). Examples: Benzodiazepines and other sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, gabapentinoids (gabapentin or pregabalin), other opioids, alcohol. Potentially Arrhythmogenic Agents Clinical Impact: Pharmacodynamic interactions may occur with concomitant use of methadone and potentially arrhythmogenic agents or drugs capable of inducing electrolyte disturbances (hypomagnesemia, hypokalemia).
Intervention: Monitor patients closely for cardiac conduction changes. Examples: Drugs known to have potential to prolong QT interval : Class I and III antiarrhythmics, some neuroleptics and tricyclic antidepressants, and calcium channel blockers. Drugs capable of inducing electrolyte disturbances : Diuretics, laxatives, and, in rare cases, mineralocortocoid hormones. Serotonergic Drugs Clinical Impact: The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome (see WARNINGS , PRECAUTIONS ).
Intervention: If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment. Discontinue Methadone Hydrochloride Injection if serotonin syndrome is suspected. Examples: Selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that effect the serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), certain muscle relaxants (i.e., cyclobenzaprine, metaxalone), monoamine oxidase (MAO) inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue).
Monoamine Oxidase Inhibitors (MAOIs) Clinical Impact: MAOI interactions with opioids may manifest as serotonin syndrome (see PRECAUTIONS ) or opioid toxicity (e.g., respiratory depression, coma) (see PRECAUTIONS ) . Intervention: The use of Methadone Hydrochloride Injection is not recommended for patients taking MAOIs or within 14 days of stopping such treatment. Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics Clinical Impact: May reduce the analgesic effect of Methadone Hydrochloride Injection and/or precipitate withdrawal symptoms.
Intervention: Avoid concomitant use. Examples: butorphanol, nalbuphine, pentazocine, buprenorphine Muscle Relaxants Clinical Impact: Methadone may enhance the neuromuscular blocking action of skeletal muscle relaxants and produce an increased degree of respiratory depression. Intervention: Monitor patients for signs of respiratory depression that may be greater than otherwise expected and decrease the dosage of Methadone Hydrochloride Injection and/or the muscle relaxant as necessary.
Examples: cyclobenzaprine, metaxalone Diuretics Clinical Impact: Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Intervention: Monitor patients for signs of diminished diuresis and/or effects on blood pressure and increase the dosage of the diuretic as needed. Anticholinergic Drugs Clinical Impact: The concomitant use of anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Intervention: Monitor patients for signs of urinary retention or reduced gastric motility when Methadone Hydrochloride Injection is used concomitantly with anticholinergic drugs. Anti-Retroviral Agents Nevirapine Based on the known metabolism of methadone, nevirapine may decrease plasma concentrations of methadone by increasing its hepatic metabolism. Opioid withdrawal syndrome has been reported in patients treated with nevirapine and methadone concomitantly.
Methadone-maintained patients beginning nevirapine therapy should be monitored for evidence of withdrawal and methadone dose should be adjusted accordingly. Efavirenz Coadministration of efavirenz in HIV-infected methadone-maintenance patients has resulted in decreased methadone plasma concentrations of methadone associated with signs of opioid withdrawal, and necessitating increases in methadone dose. Ritonavir and Ritonavir/Lopinavir Reduced plasma methadone levels have been observed after administration of ritonavir alone or ritonavir/lopinavir comb
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Pregnancy and breastfeeding
Pregnancy There are no pharmacokinetic studies of parenteral methadone in pregnancy. The disposition of oral methadone has been studied in approximately 30 pregnant patients in 2 nd and 3 rd trimesters. Elimination of methadone was significantly changed in pregnancy. Total body clearance of methadone was increased in pregnant patients compared to the same patients postpartum or to non-pregnant opioid-dependent women.
The terminal half-life of methadone is decreased during second and third trimesters. The decrease in plasma half-life and increased clearance of methadone resulting in lower methadone trough levels during pregnancy can lead to withdrawal symptoms in some pregnant patients. The dosage may need to be increased or the dosing interval decreased in pregnant patients receiving methadone (see DOSAGE AND ADMINISTRATION ). Pregnancy Neonatal Opioid Withdrawal Syndrome Advise women that if they are pregnant while being treated with Methadone Hydrochloride Injection, the baby may have signs of withdrawal at birth and that withdrawal is treatable (see BOXED WARNING , WARNINGS: Neonatal Opioid Withdrawal Syndrome , PRECAUTIONS: Pregnancy ) Embryo-Fetal Toxicity Inform female patients of reproductive potential that Methadone Hydrochloride Injection can cause fetal harm and to inform their healthcare provider of a known or suspected pregnancy (see PRECAUTIONS: Pregnancy ).
Pregnancy Risk Summary The majority of available data from clinical trials, observational studies, case series, and case reports on methadone use in pregnancy do not indicate an increased risk of major malformations specifically due to methadone. Pregnant women involved in methadone maintenance programs have been reported to have improved prenatal care leading to reduced incidence of obstetric and fetal complications and neonatal morbidity and mortality when compared to women using illicit drugs.
Several factors, including maternal use of illicit drugs, nutrition, infection and psychosocial circumstances, complicate the interpretation of investigations of the children of women who take methadone during pregnancy. Information is limited regarding dose and duration of methadone use during pregnancy, and most maternal exposure in these studies appears to occur after the first trimester of pregnancy ( see Data ).
Neonatal opioid withdrawal syndrome (NOWS) is an expected and treatable outcome of prolonged use of opioids during pregnancy (see WARNINGS , PRECAUTIONS ). In published animal reproduction studies, methadone administered subcutaneously during the early gestational period produced neural tube defects (i.e., exencephaly and cranioschisis) in the hamster at doses 2 times the human daily oral dose of 120 mg/day on a mg/m 2 basis (HDD) and in mice at doses equivalent to the HDD.
Administration of methadone to pregnant animals during organogenesis and through lactation resulted decreased litter size, increased pup mortality, decreased pup body weights, developmental delays, and long-term neurochemical changes in the brain of offspring which correlate with altered behavioral responses that persist through adulthood at exposures comparable to and less than the HDD. Administration of methadone to male rodents prior to mating with untreated females resulted in increased neonatal mortality and significant differences in behavioral tests in the offspring at exposures comparable to and less than the HDD ( see Data ).
Based on animal data, advise pregnant women of the potential risk to a fetus. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.
Clinical Considerations Disease-associated Maternal and Embryo-fetal risk Untreated opioid addiction in pregnancy is associated with adverse obstetrical outcomes such as low birth weight, preterm birth, and fetal death. In addition, untreated opioid addiction often results in continued or relapsing illicit opioid use. Dosage Adjustment During Pregnancy Dosage adjustment using higher doses or administering the daily dose in divided doses may be necessary in pregnant women treated with Methadone Hydrochloride Injection.
Pregnant women appear to have significantly lower trough plasma methadone concentrations, increased plasma methadone clearance, and shorter methadone half-life than after delivery (see DOSAGE AND ADMINISTRATION and CLINICAL PHARMACOLOGY ). Withdrawal signs and symptoms should be closely monitored and the dose adjusted as necessary. Fetal/Neonatal Adverse Reactions Neonatal opioid withdrawal syndrome may occur in newborn infants of mothers who are receiving treatment with Methadone Hydrochloride Injection.
Neonatal opioid withdrawal syndrome presents as irritability, hyperactivity and abnormal sleep pattern, high pitched cry, tremor, vomiting, diarrhea, and/or failure to gain weight. Signs of neonatal withdrawal usually occur in the first days after birth. The duration and severity of neonatal opioid withdrawal syndrome may vary. Observe newborns for signs of neonatal opioid withdrawal syndrome and manage accordingly (see BOXED WARNING , WARNINGS: Neonatal Opioid Withdrawal Syndrome ).
Labor or Delivery Opioid-dependent women on methadone maintenance therapy may require additional analgesia during labor. Monitor neonates exposed to opioid analgesics during labor for signs of excess sedation and respiratory depression. Data Human Data The majority of available data from clinical trials, observational studies, case series, and case reports on methadone use in pregnancy do not indicate an increased risk of major malformations specifically due to methadone.
Findings regarding specific major malformations, decreased fetal growth, premature birth and Sudden Infant Death Syndrome have been inconsistent. Children prenatally exposed to methadone have been reported to demonstrate mild but persistent deficits in performance on psychometric and behavioral tests and visual abnormalities. In a multicenter, double-blind, randomized, controlled trial [Maternal Opioid Treatment: Human Experimental Research (MOTHER)] designed primarily to assess neonatal opioid withdrawal effects, opioid-dependent pregnant women were randomized to buprenorphine (n = 86) or methadone (n = 89) treatment, with enrollment at an average gestational age of 18.7 weeks in both groups.
A total of 28 of the 86 women in the buprenorphine group (33%) and 16 of the 89 women in the methadone group (18%) discontinued treatment before the end of pregnancy. Among women who remained in treatment until delivery, there was no difference between methadone-treated and buprenorphine-treated groups in the number of neonates requiring NOWS treatment or in the peak severity of NOWS. Buprenorphine-exposed neonates required less morphine (mean total dose, 1.1 mg vs. 10.4 mg), had shorter hospital stays (10.0 days vs. 17.5 days), and shorter duration of treatment for NOWS (4.1 days vs. 9.9 days) compared to the methadone-exposed group.
There were no differences between groups in other primary outcomes (neonatal head circumference) or secondary outcomes (weight and length at birth, preterm birth, gestational age at delivery, and 1-minute and 5-minute Apgar scores), or in the rates of maternal or neonatal adverse events. The outcomes among mothers who discontinued treatment before delivery and may have relapsed to illicit opioid use are not known. Because of the imbalance in discontinuation rates between the methadone and buprenorphine groups, the study findings are difficult to interpret.
Animal Data Formal reproductive and developmental toxicology studies for methadone have not been conducted. Exposure margins for the following published study reports are based on a human daily
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Adverse reactions
The following serious adverse reactions are described, or described in greater detail, in other sections:
Addiction, Abuse, and Misuse (see WARNINGS )
Life Threatening Respiratory Depression (see WARNINGS )
QT Prolongation (see WARNINGS )
Neonatal Opioid Withdrawal Syndrome (see WARNINGS )
Interactions with CNS Depressants (see WARNINGS )
Serotonin Syndrome (see WARNINGS )
Adrenal Insufficiency (see WARNINGS )
Severe Hypotension (see WARNINGS )
Gastrointestinal Adverse Reactions (see WARNINGS )
Seizures (see WARNINGS )
Withdrawal (see WARNINGS )
Hypoglycemia (see WARNINGS ) The following adverse reactions associated with the use of methadone were identified in clinical studies or post-marketing reports. Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. The major hazards of methadone are respiratory depression and, to a lesser degree, systemic hypotension. Respiratory arrest, shock, cardiac arrest, and death have occurred. The most frequently observed adverse reactions include lightheadedness, dizziness, sedation, nausea, vomiting, and sweating. These effects seem to be more prominent in ambulatory patients and in those who are not suffering severe pain. In such individuals, lower doses of methadone are advisable. Other adverse reactions that have been reported in patients (including opioid addicts taking methadone for detoxification or maintenance) receiving methadone include the following: Body as a Whole : asthenia (weakness), edema, headache Cardiovascular: Arrhythmias, bigeminal rhythms, bradycardia, extrasystoles, tachycardia, Torsade de Pointes, ventricular fibrillation, ventricular tachycardia. ECG abnormalities, prolonged QT interval, T-wave inversion, cardiomyopathy, flushing, heart failure, hypotension, palpitations, phlebitis, syncope Digestive: Abdominal pain, anorexia, biliary tract spasm, constipation, dry mouth, glossitis Hematologic and Lymphatic: Reversible thrombocytopenia has been described in opioid addicts with chronic hepatitis. Metabolic and Nutritional: Hypokalemia, hypomagnesemia, weight gain Central Nervous System: Agitation, confusion, seizures, disorientation, dysphoria, euphoria, insomnia, hallucinations, seizures, visual disturbances, congenital oculomotor disorders (nystagmus, strabismus) Respiratory: Pulmonary edema Skin and Appendages: Intramuscular and Subcutaneous: Local tissue reactions (pain, erythema, swelling), particularly with continuous subcutaneous infusion Intravenous: Pruritis, urticaria, other skin rashes, and rarely, hemorrhagic urticaria Special Senses: Visual disturbances Urogenital: Antidiuretic effect, amenorrhea, urinary retention or hesitancy, reduced libido and/or potency Serotonin Syndrome : Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of opioids with serotonergic drugs. Adrenal Insufficiency : Cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use. Anaphylaxis: Anaphylaxis has been reported with ingredients contained in Methadone Hydrochloride Injection. Androgen Deficiency: Cases of androgen deficiency have occurred with use of opioids for an extended period of time. Hyperalgesia and Allodynia: Cases of hyperalgesia and allodynia have been reported with opioid therapy of any duration (see WARNINGS ). Hypoglycemia: Cases of hypoglycemia have been reported in patients taking methadone (see WARNINGS ). Opioid-Induced Esophageal Dysfunction (OIED): Cases of OIED have been reported in patients taking opioids and may occur more frequently in patients taking higher doses of opioids, and/or in patients taking opioids longer term (see WARNINGS). Adverse Reactions from Observational Studies A prospective, observational cohort study estimated the risks of addiction, abuse, and misuse in patients initiating long-term use of Schedule II opioid analgesics between 2017 and 2021. Study participants included in one or more analyses had been enrolled in selected insurance plans or health systems for at least one year, were free of at least one outcome at baseline, completed a minimum number of follow-up assessments, and either: 1) filled multiple extended-release/long-acting opioid analgesic prescriptions during a 90-day period (n = 978); or 2) filled any Schedule II opioid analgesic prescriptions covering at least 70 of 90 days (n = 1,244). Those included also had no dispensing of the qualifying opioids in the previous 6 months. Over 12 months:
approximately 1% to 6% of participants across the two cohorts newly met criteria for addiction, as assessed with two validated interview-based measures of moderate-to-severe opioid use disorder based on Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria, and
approximately 9% and 22% of participants across the two cohorts newly met criteria for prescription opioid abuse and misuse (defined in DRUG ABUSE AND DEPENDENCE ), respectively, as measured with a validated self-reported instrument. A retrospective, observational cohort study estimated the risk of opioid-involved overdose or opioid overdose-related death in patients with new long-term use of Schedule II opioid analgesics from 2006 through 2016 (n = 220,249). Included patients had been enrolled in either one of two commercial insurance programs, one managed care program, or one Medicaid program for at least 9 months. New long-term use was defined as having Schedule II opioid analgesic prescriptions covering at least 70 days’ supply over the 3 months prior to study entry and none during the preceding 6 months. Patients were excluded if they had an opioid-involved overdose in the 9 months prior to study entry. Overdose was measured using a validated medical code-based algorithm with linkage to the National Death Index database. The 5-year cumulative incidence estimates for opioid-involved overdose or opioid overdose-related death ranged from approximately 1.5% to 4% across study sites, counting only the first event during follow-up. Approximately 17% of first opioid overdoses observed over the entire study period (5-11 years, depending on the study site) were fatal. Higher baseline opioid dose was the strongest and most consistent predictor of opioid-involved overdose or opioid overdose-related death. Study exclusion criteria may have selected patients at lower risk of overdose, and substantial loss to follow-up (approximately 80%) also may have biased estimates. The risk estimates from the studies described above may not be generalizable to all patients receiving opioid analgesics, such as those with exposures shorter or longer than the duration evaluated in the studies.
Composition
Active ingredients
METHADONE HYDROCHLORIDE 10MG/ML
Strengths and forms
The FDA lists each strength of a product separately; these pages share one label.
Prognia shows this product information for reference and learning. It is not treatment advice and can lag behind the official text. Always check the current product information and local protocols before prescribing.
