biostudies-literatureUnknown10Fernandes M<b>Background:</b>  Cancer is the second leading cause of death globally. Up to 86% of advanced cancer patients experience significant pain, while 10-20% live in chronic pain. Besides, increasing prescription of opioids resulted in 33,000 deaths in the US in 2015. Both reduce patients' functional status and quality of life. While cancer survival rates are increasing, therapeutic options for chronic opioid refractory pain are still limited. Esketamine is the s-enantiomer of ketamine, with superior analgesic effect and less psychotomimetic side effects. Intranasal esketamine was approved by the FDA for treatment-resistant depression. However, its use in chronic cancer pain has never been tested. Therefore, we propose a phase II, randomized, placebo-controlled trial to evaluate the efficacy aF1000Research42https://www.ebi.ac.uk/biostudies/studies/S-EPMC7885290biostudies-literatureIMPORTANCE trial: a provisional study-design of a single-center, phase II, double-blinded, placebo-controlled, randomized, 4-week study to compare the efficacy and safety of intranasal esketamine in chronic opioid refractory pain.PMC7885290Hamad Bek SAToyomi de Oliveira SDroppelmann GWinter Matos AMWaqar KPerera Valdivia DUygur Kucukseymen EAlbuquerque Sousa LHDoldi PMVaz de Macedo AMenon Miyake MChaker MFernandes MXavier NFBenitez BKBernardo da Silva RAriza Manzano AABasendwah AMMilani GAlkhozondar OMJSchelotto MRomanelli Tavares VLHamdy Abdelrahim YNakamura RFregni FZertuche Maldonado TfalseIMPORTANCE trial: a provisional study-design of a single-center, phase II, double-blinded, placebo-controlled, randomized, 4-week study to compare the efficacy and safety of intranasal esketamine in chronic opioid refractory pain.<b>Background:</b>  Cancer is the second leading cause of death globally. Up to 86% of advanced cancer patients experience significant pain, while 10-20% live in chronic pain. Besides, increasing prescription of opioids resulted in 33,000 deaths in the US in 2015. Both reduce patients' functional status and quality of life. While cancer survival rates are increasing, therapeutic options for chronic opioid refractory pain are still limited. Esketamine is the s-enantiomer of ketamine, with superior analgesic effect and less psychotomimetic side effects. Intranasal esketamine was approved by the FDA for treatment-resistant depression. However, its use in chronic cancer pain has never been tested. Therefore, we propose a phase II, randomized, placebo-controlled trial to evaluate the efficacy a2021-01-01T00:00:00Z20212025-04-03T21:32:40.036Z2025-04-03T21:32:40.036ZS-EPMC78852903373243410.12688/f1000research.27809.1