A pilot study was initiated in seven methadone injecting patients to examine whether intravenous methadone use in patients in oral methadone maintenance treatment could be decreased by increased oral methadone dose. During the study, patients had a standardized methadone dose increase for three weeks, followed by a 12-week follow-up period. Mean methadone doses prior to, and at the end of the study, were 99 mg/day and 163 mg/day, respectively. On week 15, the mean frequency of injection and the mean proportion of methadone dose injected were reduced to 46% of the values measured at week 0. Two patients did not modify their frequency, nor their dose of injected methadone, four patients decreased their use of injectable methadone, while one completely stopped injecting methadone. Five patients did not change their frequency of injection. Nine patients decreased their frequency of methadone injection from a mean 95% down to 35%. Finally, four patients completely stopped injecting methadone Although the present results have to be confirmed by controlled studies including a larger number of patients, when considering the high frequency of methadone injection in some places and the associated problems, the therapeutic option of increasing methadone dose should be considered further. (PsycINFO Database Record (c) 2004 APA, all rights reserved)