Methadone

Uses

Pain

  • PO: legitimately or illegitimately

Abuse

  • IV: addicts dissolve and inject methadone

Pharmacology

Metabolism

  • xxx

Administration

  • PO
    • Pre-Treatment EKG: required for determine baseline QT interval
    • Follow-Up EKG at 30 Days: recommended
    • Annual EKG: recommended

Dose Adjustment

  • Hepatic
  • Renal

Adverse Effects

Cardiovascular Adverse Effects

Q-T Prolongation with Definite Association with Torsade (see Torsade, Torsade)

  • Epidemiology
    • FDA Black Box Warning Related to Risk of Torsade: issued in 2006
    • Most cases of torsade are associated with high methadone doses or recent methadone dose increase
  • Clinical:

Gastrointestinal Adverse Effects

Increased Risk of Hepatic Encephalopathy (see Hepatic Encephalopathy, Hepatic Encephalopathy)

  • xxxx

Pulmonary Adverse Effects

Acute Lung Injury-ARDS (see Acute Lung Injury-ARDS, Acute Lung Injury-ARDS)

  • Epidemiology: has been reported with both PO and IV use
  • Treatment: supportive

Respiratory Depression

Talc/Foreign Body Granulomatosis (see Foreign Body Granulomatosis, Foreign Body Granulomatosis)

  • Epidemiology: associated with intravenous methadone abuse

Toxicologic Adverse Effects

Serotonin Syndrome (see Serotonin Syndrome, Serotonin Syndrome)

  • xxxx

Methadone Intoxication

Clinical

  • xxx
  • xxx
  • xxx

Diagnosis

  • Urine Toxicology Screen: methadone can give false-negative urine toxicology screen for opiates

Treatment


References

  • A case of serotonin syndrome associated with methadone overdose. Proc West Pharmacol Soc. 2008;51:42-4 [ MEDLINE]