Methadone Hydrochloride

1 INDICATIONS AND USAGE Methadone hydrochloride tablets for oral suspension contain methadone, an opioid agonist indicated for the: Detoxification treatment of opioid addiction (heroin or other morphine-like drugs). Maintenance treatment of opioid addiction (heroin or other morphine-like drugs), in conjunction with appropriate social and medical services. Limitations of Use Methadone products used for the treatment of opioid addiction in detoxification or maintenance programs are subject to the conditions for distribution and use required under 42 CFR 8.12 [see Dosage and Administration ( 2.1 )] . Methadone hydrochloride tablets for oral suspension are an opioid agonist indicated for the: Detoxification treatment of opioid addiction (heroin or other morphine-like drugs) ( 1 ) Maintenance treatment of opioid addiction (heroin or other morphine-like drugs), in conjunction with appropriate social and medical services. ( 1 ) Limitations of Use Methadone products used for the treatment of opioid addiction in detoxification or maintenance programs are subject to the conditions for distribution and use required under 21 CFR, Title 42, Sec 8. ( 1 , 2.1 )

2 DOSAGE AND ADMINISTRATION Strongly consider recommending or prescribing an opioid overdose reversal agent (e.g., naloxone, nalmefene) at the time methadone hydrochloride tablets for oral suspension is initiated or renewed because patients being treated with methadone may be at risk for opioid overdose during initiation or titration, or in the case of relapse to illicit use. ( 2.3 ) Initiation of Detoxification and Maintenance Treatmen t : A single dose of 20 to 30 mg may be sufficient to suppress withdrawal syndrome. ( 2.5 ) Maintenance Treatment : Clinical stability is most commonly achieved at doses between 80 to 120 mg/day. ( 2.6 ) Do not rapidly reduce or abruptly discontinue methadone hydrochloride tablets for oral suspension in a physically-dependent patient ( 2.7 , 5.15 ) 2.1 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)). 2.2 Important Dosage and Administration Information Methadone hydrochloride tablets for oral suspension are for oral administration only. The preparation must not be injected. Methadone should be kept out of reach of children to prevent accidental ingestion. Consider the following important factors that differentiate methadone from other opioids: The peak respiratory depressant effect of methadone occurs later and persists longer than its peak pharmacologic effect. A high degree of opioid tolerance does not eliminate the possibility of methadone overdose, iatrogenic or otherwise. Deaths have been reported during conversion to methadone from chronic, high-dose treatment with other opioid agonists and during initiation of methadone treatment of addiction in subjects previously abusing high doses of other opioid agonists. There is high interpatient variability in absorption, metabolism, and relative analgesic potency. Population-based conversion ratios between methadone and other opioids are not accurate when applied to individuals. With repeated dosing, methadone is retained in the liver and then slowly released, prolonging the duration of potential toxicity. Steady-state plasma concentrations are not attained until 3 to 5 days after initiation of dosing . Methadone hydrochloride tablets for oral suspension have a narrow therapeutic index, especially when combined with other drugs. 2.3 Patient Access to an Opioid Overdose Reversal Agent for the Emergency Treatment of Opioid Overdose Inform patients and caregivers about opioid overdose reversal agents (e.g., naloxone, nalmefene) and discuss the importance of having access to an opioid overdos…

5 WARNINGS AND PRECAUTIONS N e o natal Op i o i d Withdrawal Syndrome: Neonatal opioid withdrawal syndrome (NOWS) is an expected and treatable outcome of prolonged use of opioids during pregnancy. ( 5.6 ) L i f e - T h r e at e nin g Respiratory Depression in Patients with Chronic Pulmonary Disease or in Elderly, Cachectic, or Debilitated Patients: Monitor closely, particularly during initiation and titration. ( 5.8 ) S e ro t o ni n Syndrome: Potentially life-threatening condition could result from concomitant serotonergic drug administration. Discontinue methadone hydrochloride tablets for oral suspension if serotonin syndrome is suspected. ( 5.9 ) A d r e na l Insufficiency: If diagnosed, treat with physiologic replacement of corticosteroids, and wean patient off of the opioid. ( 5.10 ) S e v e r e Hypotension: Monitor during dose initiation and titration. ( 5.11 ) Ri s k s of Use in Patients with Head Injury and Increased Intracranial Pressure: Monitor for sedation and respiratory depression. Avoid use of methadone in patients with impaired consciousness or coma susceptible to intracranial effects of CO 2 retention. ( 5.12 ) 5.1 Life-Threatening Respiratory Depression Serious, life-threatening, or fatal respiratory depression has been reported with the use of methadone, even when used as recommended. Respiratory depression, if not immediately recognized and treated, may lead to respiratory arrest and death. Respiratory depression from opioids is manifested by a reduced urge to breathe and a decreased rate of respiration, often associated with a “sighing” pattern of breathing (deep breaths separated by abnormally long pauses). Carbon dioxide (CO 2 ) retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids. Management of respiratory depression may include close observation, supportive measures, and use of opioid overdose reversal agents, depending on the patient’s clinical status [see Overdosage ( 10 )]. While serious, life-threatening, or fatal respiratory depression can occur at any time during the use of methadone hydrochloride tablets for oral suspension, the risk is greatest during the initiation of therapy or following a dose increase. The peak respiratory depressant effect of methadone occurs later, and persists longer than the peak pharmacologic effect, especially during the initial dosing period. Monitor patients closely for respiratory depression, when initiating therapy with methadone hydrochloride tablets for oral suspension and following dose increases. Instruct patients against use by individuals other than the patient for whom methadone was prescribed and to keep methadone out of the reach of children, as such inappropriate use may result in fatal respiratory depression [see Patient Counseling Information ( 17 )] . To reduce the risk of respiratory depression, proper dosing and titration of methadone are essential [see Dosage and Administration ( 2.5 )] . Overestimating the methadone dosage when initiating treatment can result in fatal overdose with the first dose. To further reduce the risk of respiratory depression, consider the following: Patients tolerant to other opioids may be incompletely tolerant to methadone. Incomplete cross-tolerance is of particular concern for patients tolerant to other mu-opioid agonists. Deaths have been reported during conversion from chronic, high-dose treatment with other opioid agonists. Follow induction directions closely to avoid inadvertent overdose [see Dosage and Administration ( 2.5 )] . Proper dosing and titration are essential and methadone should be overseen only by healthcare professionals who are knowledgeable in the pharmacokinetics and pharmacodynamics of methadone. Educate patients and caregivers on how to recognize respiratory depression and emphasize the importance of calling 911 or getting emergency medical help right away in the event of a known or suspected overdose [see Patient Counseling Information ( 17 )] . Op…

4 CONTRAINDICATIONS Methadone hydrochloride tablets for oral suspension are contraindicated in patients with: Significant respiratory depression [see Warnings and Precautions ( 5.1 )]. Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment [see Warnings and Precautions ( 5.8 )]. Known or suspected gastrointestinal obstruction, including paralytic ileus [see Warnings and Precautions ( 5.13 )]. Hypersensitivity (e.g. anaphylaxis) to methadone or any other ingredient in methadone hydrochloride tablets for oral suspension [see Adverse Reactions ( 6 )]. Significant respiratory depression ( 4 ) Acute or severe bronchial asthma ( 4 ) Known or suspected paralytic ileus ( 4 ) Known hypersensitivity to methadone ( 4 )

7 DRUG INTERACTIONS 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, increases the risk of respiratory depression, profound sedation, coma, and death. Intervention : Cessation of benzodiazepines or other CNS depressants is preferred in most cases of concomitant use. In some cases, monitoring in a higher level of care for taper may be appropriate. In others, gradually tapering a patient off of a prescribed benzodiazepine or other CNS depressant or decreasing to the lowest effective dose may be appropriate. Before co-prescribing benzodiazepines for anxiety or insomnia, ensure that patients are appropriately diagnosed and consider alternative medications and non-pharmacologic treatments [ see Warnings and Precautions ( 5.2 )] . If concomitant use is warranted, strongly consider prescribing naloxone for the emergency treatment of opioid overdose, as is recommended for all patients in treatment for opioid use disorder [see Warnings and Precautions ( 5.1 ) ]. Examples : Benzodiazepines, and other sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, gabapentinoids (gabapentin or pregabalin), other opioids, alcohol. 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 tablets for oral suspension 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 tablets for oral suspension 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 ( 12.3 )] , 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 tablets for oral suspension 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 tablets for oral suspension 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 tablets for oral suspension and CYP3A4, CYP2B6, CYP2C19, or CYP2C9 inducers can decrease the plasma concentration of methadone [see Clinical Pharmacology ( 12.3 )] , 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 ( 12.3 )] , 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…

8.1 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 and Precautions ( 5.6 )]. 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. C li n i cal Considerations D i sease-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 tablets for oral suspension. 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 ( 2.10 ) and Clinical Pharmacology ( 12.3 ) ]. 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 tablets for oral suspension. 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 …

8.3 Females and Males of Reproductive Potential Infertility The effect of methadone hydrochloride tablets for oral suspension on fertility is unknown. Use of opioids for an extended period of time may cause reduced fertility in females and males of reproductive potential. It is not known whether these effects on fertility are reversible [see Adverse Reactions ( 6 ), Clinical Pharmacology ( 12.2 ), Nonclinical Pharmacology ( 13.1 )]. Reproductive function in human males may be decreased by methadone treatment. Reductions in ejaculate volume and seminal vesicle and prostate secretions have been reported in methadone-treated individuals. In addition, reductions in serum testosterone levels and sperm motility, and abnormalities in sperm morphology have been reported. In published animal studies, methadone produces a significant regression of sex accessory organs and testes of male mice and rats and administration of methadone to pregnant rats reduced fetal blood testosterone and androstenedione in male offspring [see Nonclinical Toxicology ( 13 )] .

6 ADVERSE REACTIONS The following serious adverse reactions and/or conditions are described, or described in greater detail, in other sections: Respiratory Depression [see Warnings and Precautions ( 5.1 )] Interactions with Benzodiazepines and other CNS Depressants [see Warnings and Precautions ( 5.2 )] QT Prolongation [see Warnings and Precautions ( 5.3 )] Serotonin Syndrome [see Warnings and Precautions ( 5.9 )] Adrenal Insufficiency [see Warnings and Precautions ( 5.10 )] Severe Hypotension [see Warnings and Precautions ( 5.11 )] Gastrointestinal Adverse Reactions [see Warnings and Precautions ( 5.13 )] Seizures [see Warnings and Precautions ( 5.14 )] Withdrawal [see Warnings and Precautions ( 5.15 )] Hypoglycemia [see Warnings and Precautions ( 5.17 )] The following adverse reactions have been identified during post-approval use of methadone. Because these reactions are 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 included lightheadedness, dizziness, sedation, nausea, vomiting, and sweating. These effects seemed to be more prominent in ambulatory patients and in those who are not suffering severe pain. Other adverse reactions include the following: Body as a Whole: asthenia (weakness), edema, headache Cardiovascular: arrhythmias, bigeminal rhythms, bradycardia, cardiomyopathy, ECG abnormalities, extrasystoles, flushing, heart failure, hypotension, palpitations, phlebitis, QT interval prolongation, syncope, T-wave inversion, tachycardia, torsades de pointes , ventricular fibrillation, ventricular tachycardia Central Nervous System: agitation, confusion, disorientation, dysphoria, euphoria, insomnia, hallucinations, seizures, visual disturbances, congenital oculomotor disorders (nystagmus, strabismus) Endocrine: hypogonadism Gastrointestinal: abdominal pain, anorexia, biliary tract spasm, constipation, dry mouth, glossitis Hematologic: Reversible thrombocytopenia has been described in opioid addicts with chronic hepatitis. Metabolic: hypokalemia, hypomagnesemia, weight gain Musculoskeletal: decreased muscle mass and strength, osteoporosis and fractures Renal: antidiuretic effect, urinary retention or hesitancy Reproductive: amenorrhea, reduced libido and/or potency, reduced ejaculate volume, reduced seminal vesicle and prostate secretions, decreased sperm motility, abnormalities in sperm morphology Respiratory: pulmonary edema, respiratory depression Skin and Subcutaneous Tissue: pruritus, urticaria, other skin rashes, and rarely, hemorrhagic urticaria Hypersensitivity: Anaphylaxis has been reported with ingredients contained in methadone hydrochloride tablets for oral suspension. 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 tablets for oral suspension. Androgen Deficiency: Cases of androgen deficiency have occurred with chronic use of opioids [see Clinical Pharmacology ( 12.2 )]. Hypoglycemia: Cases of hypoglycemia have been reported in patients taking methadone [see Warnings and Precautions ( 5.17 )]. 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 and Precautions ( 5.13 )]. Most Common Adverse Reactions Are : lightheadedness, dizziness…