Among 105 adults with cancer pain treated with subanesthetic ketamine, 48.6% responded—achieving a 30% reduction in pain score, as-needed opioid use, or total morphine equivalent daily dose. Responders received lower fixed-rate doses (median 15 mg/hr) than non-responders (median 15–20 mg/hr), but weight-based doses did not differ between groups (0.201 vs. 0.209 mg/kg/hr). Responders had higher baseline opioid needs. The findings suggest weight-based dosing may not improve success over fixed-rate dosing, though the study was underpowered.
Microdosing induction of buprenorphine, in which the drug is gradually titrated while full agonist opioids are continued, offers a viable alternative to traditional inductions that require an opioid-free interval or withdrawal. This review of 34 publications found that the most common strategy involved administering divided doses of sublingual products marketed for opioid use disorder, with 73.5% of articles using partial tablets or films ranging from 1/8 to 1/2 of a 2 mg product. Transdermal patches, low-dose sublingual buprenorphine available in Europe, intravenous buprenorphine, and buccal buprenorphine have also been used. The speed of induction, setting, final dosing, and management of concomitant full agonists varied widely.