title: Conversion from parenteral to oral methadone.
abstract: The described ratio for methadone conversion from oral route (PO) to parenteral route (PAR) is 2:1 and from PAR to PO is 1:2. Frequently, good control of pain with methadone is PR to PO. We use methadone as a function of opioid rotation and not in the context of mortality outcome and we have noted that the traditional ratio produces toxicity problems. We present our experience with patients who we converted from PAR to PO methadone and we recommend a conversion ratio of 0.7 (PO:PAR = 1:0.7), which approximates the bioavailability of the drug administered orally.
authors.affiliation: Palliative Care Service, Institut Català d'Oncologia, L'Hospitalet de Llobregat, Barcelona, Spain. jgonzalez@ico.scs.es
authors.forename: Jesús
authors.initials: J
authors.lastname: González-Barboteo
authors.forename: Josep
authors.initials: J
authors.lastname: Porta-Sales
authors.forename: Daniel
authors.initials: D
authors.lastname: Sánchez
authors.forename: Albert
authors.initials: A
authors.lastname: Tuca
authors.forename: Xavier
authors.initials: X
authors.lastname: Gómez-Batiste
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D001682:Biological Availability; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D055104:Infusions, Subcutaneous; D008297:Male; D008691:Methadone / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D010166:Palliative Care / Q000379:methods; D012189:Retrospective Studies
chemical_list: D000701:Analgesics, Opioid; D008691:Methadone