Alderman C P, Frith P A
Repatriation General Hospital, South Australia, Australia.
Aust N Z J Psychiatry. 1999 Feb;33(1):99-101. doi: 10.1046/j.1440-1614.1999.00522.x.
The aim of this paper is to report a case of symptomatic methadone toxicity associated with fluvoxamine treatment.
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.
Methadone was decreased to 50 mg daily and diazepam was tapered to zero.
The serum methadone concentration decreased and oxygenation improved considerably.
Clinicians should be aware of the potential for a significant drug interaction between fluvoxamine and methadone.
