Methadone Hydrochloride

Registered South African indications:

• Cough suppression

Click here for the active ingredient monograph for the indication of substitution treatment in opiate/opioid dependence

Contraindications

Registered South African contraindications

• Hypersensitivity to the active ingredient or any of its excipients
• Respiratory depression, especially in the presence of cyanosis and excessive bronchial secretions
• During an attack of bronchial asthma
• In the presence of acute alcoholism, head injury, and raised intracranial pressure
• Individuals receiving monoamine oxidase inhibitors or within 14 days of stopping such treatment
• Ulcerative colitis, since it may precipitate toxic dilatation or spasm of the colon
• Severe hepatic impairment, as it may precipitate hepatic encephalopathy
• Contraindicated at recommended dosages in biliary and renal tract spasm

Cautions

• Pregnancy
• Breastfeeding
• Renal impairment
• Mild to moderate hepatic impairment
• Elderly
• Adrenocortical insufficiency
• Hypothyroidism
• Hypopituitarism
• Prostate hypertrophy
• Shock
• Diabetes mellitus
• Pheochromocytoma
• Ambulatory patients
• Endocrinopathy (hypoadrenalism and hypogonadism)
• Co-administration with CNS depressants
• May impair ability to drive or operate machinery

Forms avail. in SA and covered in this monograph: syr

South African registered indications and dosages

Cough suppression

• Oral (syr): 1-2mg (2.5-5ml), 4-6hrly

Not recommended for use in children

Pregnancy

South African recommendations

• Caution
• The safety of methadone in pregnancy has not been established

Breastfeeding

South African recommendations

• Caution
• The safety of methadone in breastfeeding women has not been established

Renal Impairment

South African recommendations

• Caution; dose adjustment recommended
  Caution should be exercised in the use of methadone in patients with renal impairment
  The dosage interval should be increased to a minimum of 8 hourly when the glomerular filtration rate (GFR) is 10-50ml/min and to a minimum of 12 hourly when the GFR is below 10ml/min

Hepatic Impairment

South African recommendations

• Mild to moderate: Caution; dose adjustment recommended
  Particular care should be taken when methadone is to be used in patients with hepatic impairment as these patients metabolise methadone more slowly than normal patients
  Where not contraindicated, methadone should be given at less than the normal recommended dose and the patient's response used as a guide to further dosage requirements
• Severe: Contraindicated

Elderly

South African recommendations

• Caution; dose adjustment recommended
  Methadone has a long plasma half-life which may lead to accumulation in elderly patients, particularly if renal function is impaired
  Where not contraindicated, methadone should be given at less than the normal recommended dose and the patient's response used as a guide to further dosage requirements
  Methadone may cause confusion in this age group, therefore careful monitoring is advised

Porphyria Information

• Probably not porphyrinogenic (PNP)

Drugs in Sport

• Prohibited - In competition

Central Nervous System Disorders

• Increased intracranial pressure
• Dizziness
• Headache
• Drowsiness
• Dependence
• Hallucinations
• Confusion
• Dysphoria
• Decreased libido

Cardiovascular Disorders

• QT prolongation
• Torsade de pointes
• Bradycardia
• Palpitations
• Tachycardia
• Hypotension
• Facial flushing

Respiratory Disorders

• Respiratory depression
• Exacerbation of existing asthma

Gastrointestinal Disorders

• Nausea and vomiting
• Constipation
• Dry mouth

Hepatobiliary Disorders

• Biliary spasm

Genitourinary Disorders

• Difficulty in micturation
• Ureteric spasm
• Antidiuretic effect
• Erectile dysfunction
• Reductions in the ejaculate volume and seminal vesicular and prostatic secretions

Endocrine and Metabolic Disorders

• Adrenal insufficiency
• Increased prolactin concentrations
• Decreased testosterone concentrations

Skin and Subcutaneous Tissue Disorders

• Rashes
• Pruritus
• Urticaria
• Excessive sweating

Immune, Blood and Lymphatic System Disorders

• Lymphocytosis

Sensory Disorders

• Miosis
• Vertigo

• Alcohol
• Opiates
• Barbiturates
• Benzodiazepines
• Monoamine oxidase inhibitors
• CYP3A4 inhibitors
• CYP3A4 inducers
• Naloxone
• Naltrexone
• Buprenorphine
• Primoquine
• Pentazocine
• Urinary acidifiers
• Domperidone
• Nucleoside reverse transcriptase inhibitors
• Drugs affected cardiac conduction
• Serotonergic drugs (SSRI, SNRI, TCA, MAO-I)

• Vital signs
• ECG

Methadone is a full mu-opioid agonist and N-methyl-D-aspartate antagonist . It is a synthetic opioid with pharmacological properties similar to morphine.  

Syrup (per 5ml) 2mg

• Physeptone (Pharmacare)