How to switch from morphine or oxycodone to methadone in cancer patients? A randomised clinical phase II trial

Serum concentrations of opioids when comparing two switching strategies to methadone for cancer pain

“…Regardless, the SAG group neither reported better pain control nor fewer side effects than the 3DS group on day 3 [20]. Thus, the claim by Mercadante et al [9] that a more rapid clearance of morphine and its metabolites with the SAG approach would result in fewer side effects and that a shorter time to stabilization of the methadone concentration would give more rapid pain relief is not supported by this study.…”

“…The two groups were similar regarding key background variables, such as sex (male:female ratio 1:1), mean age (~60 years), Karnofsky performance status (≈ 60%), and ethnicity (98% Caucasian). Details on cancer diagnoses, treatments, causes of opioid switches, concomitant diseases and drugs, pain relief, side effects, cognitive function, and QTc intervals from the switch, together with a Consolidated Standards of Reporting Trials (CONSORT) flowchart are reported elsewhere [20]. The median preswitch equianalgesic oral morphine doses in the 35 patients receiving methadone were 620 (range 350-2000) mg/day in the SAG group (n016) and 800 (range 90-3600) mg/day in the 3DS group (n019) (p00.43).…”

“…Sample-size estimation was performed for the primary clinical outcome [20]. Apparent steady state for methadone on day 4 was defined as a concentration ≥90% [29] of the methadone concentration on day 7, when steady state should have been reached.…”

“…The study reported here was a part of a randomised phase II trial examining whether SAG provided faster onset of pain relief than 3DS when switching from morphine/oxycodone to methadone [20]. The research questions for this pharmacokinetic part of the study were:…”

Smertebehandling hos kreftpasienter i legemiddelassistert rehabilitering

“…På grunn av den lange halveringstiden til metadon vil man, når man er i farmakologisk likevekt etter gjentatt dosering, få høyere effekt av metadon enn samme døgndose morfin. I studier av konvertering fra langvarig behandling med morfin til metadon, synes konverteringsratioen å vaere avhengig av opioiddosen pasienten har brukt frem til konverteringen til metadon, og det angis faktorer fra 1:4 til 1:12 (6). Imidlertid foreligger det ikke data på konvertering fra langtids metadonbehandling til morfin.…”