Methadone

Oral
Intravenous
Subcutaneous
Intramuscular
Class
Narcotic analgesics
Subclass
Synthetic opioids
Substance name
Methadone hydrochloride
Brand names
Methadose®
Common formulations
Concentrate for injectable solution
Dosage and administration
Adults patients
No dosages available
Other off-label uses
•
Treatment of restless legs syndrome
Indications for use
Labeled indications
Adults
•
Symptomatic relief of pain (moderate-to-severe)
Off-label indications
Adults
•
Treatment of restless legs syndrome
Safety risks
Boxed warnings
Obstructive sleep apnea
•
Use extreme caution with pulmonary disease such as COPD, cor pulmonale, decreased respiratory reserve, hypoxia, hypercapnia, respiratory insufficiency, upper airway obstruction, or pre-existing respiratory depression.
Orthostatic hypotension
•
Use extreme caution with a history of cardiac arrhythmias, hypokalemia, hypomagnesemia, hypotension, or hypovolemia.
Urinary retention
•
Use extreme caution with bladder obstruction, prostatic hypertrophy, urethral stricture, or renal disease.
Contraindications
Treated with MAOI therapy or other serotonergic drugs
Who have demonstrated a prior hypersensitivity reaction to methadone
Acute or severe bronchial asthma (e.g., status asthmaticus)
Known or suspected paralytic ileus
Warnings and precautions
Constipation
•
Use caution with pre-existing gastrointestinal obstruction.
Drug abuse
•
Use caution with a personal or family history of substance abuse (including alcoholism) or mental illness (e.g., major depression).
Drug withdrawal syndrome
•
Use caution with abrupt discontinuation of the drug.
Exacerbation of adrenal insufficiency
•
Use caution with pre-existing adrenal insufficiency (i.e., Addison's disease), hypothyroidism, or myxedema.
Hypogonadism
•
Use caution with chronic use of methadone.
Prolonged QT interval
•
Use caution with cardiac disease, other conditions that may increase the risk of QT prolongation or receiving medications known to cause electrolyte imbalances.
Seizures
•
Use caution with a seizure disorder.
Specific populations
Renal impairment
eGFR ≥ 10 mL/min/1.73 m²
•
Use acceptable. No dose adjustment required. Monitor for QT prolongation.
eGFR < 10 mL/min/1.73 m²
•
Reduce dose by 25%-50%. Titrate to response. Monitor for QT prolongation.
Renal replacement therapy
Continuous renal replacement
•
Use acceptable. No dose adjustment required. Monitor for QT prolongation.
Intermittent hemodialysis
•
Dose as in eGFR < 10 mL/min/1.73 m². Reduce dose by 25%-50%. Titrate to response. Monitor for QT prolongation.
Peritoneal dialysis
•
Dose as in eGFR < 10 mL/min/1.73 m². Reduce dose by 25%-50%. Titrate to response. Monitor for QT prolongation.
Hepatic impairment
Any severity
•
Reduce dose. Titrate slowly. Monitor for toxicity.
Substantial chronic alcohol consumption
•
Use with caution.
Pregnancy and breastfeeding
Pregnancy
All trimesters • Australia Category: C, C
•
Use only if benefits outweigh potential risks. Evidence of fetal harm in animals. Monitor for neonatal opioid withdrawal syndrome. Prolonged use of opioids during pregnancy can result in physical dependence in the neonate; women should be advised of the risk of neonatal abstinence syndrome and ensure that appropriate treatment will be available.
•
Due to pharmacokinetic differences during pregnancy (significantly lower trough plasm concentrations, shorter half-life than after delivery), the methadone dose may need to be increased or the dosing interval decreased to achieve therapeutic effectiveness.
•
This drug should not be used during and immediately prior to labor when short-acting analgesics or other analgesic techniques are more appropriate.
•
Reports indicate pregnant patients involved in methadone maintenance programs have improved prenatal care (leading to reduced incidence of obstetric and fetal complications and neonatal morbidity and mortality) compared to those using illicit drugs; several factors, including maternal drug use, nutrition, infection, and psychosocial circumstances, complicate the interpretation of investigations of the children exposed to methadone during pregnancy.
•
Information regarding the dose and duration of methadone use during pregnancy is limited, and most maternal exposure in these studies appears to occur after the first trimester of pregnancy.
•
Animal reproduction studies of subcutaneous methadone administered during early gestation produced neural tube defects (i.e., exencephaly and cranioschisis) at doses equivalent to 2 times the human daily oral dose (HDD); advise pregnant patients of the potential risk to a fetus.
•
Neonatal opioid withdrawal syndrome (NOWS) is an expected and treatable outcome of prolonged opioids use during pregnancy.
•
NOWS presents as irritability, hyperactivity and abnormal sleep pattern, high pitched cry, tremor, vomiting, diarrhea, and/or failure to gain weight. Signs usually occur in the first days after birth; duration and severity of NOWs may vary.
•
Observe newborns for signs of NOWS and manage accordingly.
Breastfeeding
Consider alternative agents that may be safer.
Low levels in breastfed infants (5-25%).
May potentially cause adverse effects in breastfed infants.
Some adverse effects on lactation reported.
Adverse reactions
Unknown frequency
•
Adrenal insufficiency, anaphylaxis, bone fracture, bradycardia, cardiac arrhythmias, ↓ blood glucose, ↓ serum magnesium, ↓ serum potassium, dependence and withdrawal reactions, diaphoresis, drug-induced liver injury, edema, gynecomastia, hypogonadism, hypotension, leukoencephalopathy, myoclonus, nystagmus, osteoporosis, premature ventricular contractions, ↑QTc interval, pulmonary edema, asthenia, constipation, dizziness, galactorrhea, hallucinations, headache, ↑ appetite, lightheadedness, loss of appetite, menstrual irregularity, nausea, seizure, sexual dysfunction, sweating, urinary retention, vomiting, weight gain, respiratory acidosis, respiratory arrest, respiratory depression, sedation, serotonin syndrome, skin erythema, skin induration, strabismus, tachycardia, torsade de pointes, urticaria
Interactions
Drug(s)
Check Interactions
Reset

What did you think about this content?

Create free account

Sign up for free to access the full drug resource