The journal of pain : official journal of the American Pain Society
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Randomized Controlled Trial Multicenter Study
OPRM1 Methylation Contributes to Opioid Tolerance in Cancer Patients.
Cancer patients in pain require high doses of opioids and quickly become opioid-tolerant. Previous studies have shown that chronic cancer pain as well as high-dose opioid use lead to mu-opioid receptor downregulation. In this study we explore downregulation of the mu-opioid receptor gene (OPRM1), as a mechanism for opioid tolerance in the setting of opioid use for cancer pain. ⋯ We focus on 2 main cells within the cancer microenvironment: the cancer cell and the neuron. We show that targeted re-expression of mu-opioid receptor on cancer cells inhibits mechanical and thermal hypersensitivity, and prevents opioid tolerance, in the mouse model. The resultant analgesia and protection against opioid tolerance are likely due to preservation of mu-opioid receptor expression on the cancer-associated neurons.
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Randomized Controlled Trial Multicenter Study
A longitudinal randomized trial of the impact of consistent pain management for infant vaccinations on future vaccination distress.
The objective was to determine if consistent pain management during vaccine injections has a beneficial effect on future infant pain reactivity. This was a multicenter, longitudinal, double-blind, double-dummy, add-on, randomized controlled trial. Healthy infants were randomized to 1 of 4 add-on pain management regimens for all vaccinations in the first year of life: 1) placebo control (standard care), 2) parent video education about infant soothing (video), 3) video and oral sucrose solution (sucrose), 4) video and sucrose and topical liposomal lidocaine (lidocaine). ⋯ Altogether, 352 infants participated; characteristics did not differ among groups (P > .05). Pain scores did not differ among groups during baseline (P = .642), needle injection (P = .739), or recovery (P = .750) phases. In conclusion, there was no evidence of a long-term benefit of consistent use of pain interventions in the first year of life on future infant pain responsivity at 15-month vaccinations.