title: [Optimal conversion ratio of oral morphine to transdermal fentanyl patches to the cancer pain].
abstract: In Japan, the initial dose of 2.5 mg/3 d is recommended in the package insert of the fentanyl patch preparation to substitute for oral morphine in the dose range of 45-135 mg/d (90 mg/d at the midpoint), while a higher dose is recommended in other countries. To validate the recommended dose of this drug in Japan, we investigated how long the initial recommended dose of the fentanyl patch could control the pain of cancer patients after the switch from other opioids. The dose of the fentanyl patch was increased on the 20th day after the switch from prior opioids at a lower dose than the midpoint of the indicated range, while it was increased on the 3rd day after the switch from the higher dose of prior opioids. Regression analysis showed that the efficacy ratio of the fentanyl patch : oral morphine=80 : 1, suggesting that oral morphine of 25-75 mg/d should be substituted for by the fentanyl patch preparation at a dose of 2.5 mg/3 d.
authors.affiliation: Department of Pharmacy, Gunma University Hospital, Gunma, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Ogawa
authors.forename: Katsunori
authors.initials: K
authors.lastname: Nakamura
authors.forename: Keiko
authors.initials: K
authors.lastname: Iizuka
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sekizuka
authors.forename: Koujirou
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Ryuya
authors.initials: R
authors.lastname: Horiuchi
mesh_terms: D000279:Administration, Cutaneous; D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D004304:Dosage Forms; D054796:Drug Dosage Calculations; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage*; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage*; D009369:Neoplasms / Q000150:complications*; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D012044:Regression Analysis; D013997:Time Factors
chemical_list: D000701:Analgesics, Opioid; D004304:Dosage Forms; D009020:Morphine; D005283:Fentanyl