Fluvoxamine-methadone interaction.
OBJECTIVE
The aim of this paper is to report a case of symptomatic methadone toxicity associated with fluvoxamine treatment.


METHODS
A 28-year-old woman was admitted to hospital with severe hypoxaemia and hypercapnia indicating hypoventilation. Medication prior to admission had been stable and included methadone 70 mg daily and diazepam 2 mg twice daily. Three weeks before admission she had commenced treatment with fluvoxamine.


METHODS
Methadone was decreased to 50 mg daily and diazepam was tapered to zero.


RESULTS
The serum methadone concentration decreased and oxygenation improved considerably.


CONCLUSIONS
Clinicians should be aware of the potential for a significant drug interaction between fluvoxamine and methadone.
Alderman
C P
CP
Repatriation General Hospital, South Australia, Australia. saldecp@rgh.sa.gov.au
Frith
P A
PA
D000328:Adult; D018687:Antidepressive Agents, Second-Generation / Q000627:therapeutic use*; D003866:Depressive Disorder / Q000188:drug therapy*; D004347:Drug Interactions; D005260:Female; D016666:Fluvoxamine / Q000627:therapeutic use*; D006801:Humans; D006935:Hypercapnia / Q000175:diagnosis; D000860:Hypoxia / Q000175:diagnosis; D008691:Methadone / Q000627:therapeutic use*; D009294:Narcotics / Q000627:therapeutic use*; D019966:Substance-Related Disorders / Q000188:drug therapy
D018687:Antidepressive Agents, Second-Generation; D009294:Narcotics; D016666:Fluvoxamine; D008691:Methadone