Javier Muriel (Neuropharmacology applied to Pain, Alicante; Institute for Health and Biomedical Research, Alicante), Mónica Escorial (Neuropharmacology applied to Pain, Alicante; Institute for Health and Biomedical Research, Alicante; Institute of Bioengineering ,Miguel Hernández University of Elche), César Margarit (Neuropharmacology applied to Pain, Alicante; Institute for Health and Biomedical Research, Alicante; Pain Unit, Dr. Balmis General University Hospital of Alicante), Jordi Barrachina (Neuropharmacology applied to Pain, Alicante; Institute for Health and Biomedical Research, Alicante; Institute of Bioengineering ,Miguel Hernández University of Elche), Cristian Carvajal (Institute of Bioengineering Miguel Hernández University of Elche), Domingo Morales (Operations Research Centre, Miguel Hernández University of Elche) and Ana M. Peiró (Neuropharmacology applied to Pain, Alicante; Institute for Health and Biomedical Research, Alicante; Institute of Bioengineering Miguel Hernández University of Elche; Pain Unit, Dr. Balmis General University Hospital, Alicante; Clinical Pharmacology Department, Dr. Balmis General University Hospital ISABIAL)
Abstract:
More than half of patients with opioid use disorder for chronic non-cancer pain (CNCP) reduced their dose through a progressive opioid withdrawal supported by a rotation to buprenorphine and/or tramadol. The aim of this research is to analyse the long-term effectiveness of opioid deprescription taking into account the impact of sex and pharmacogenetics on the inter-individual variability. A cross-sectional study was carried out from October 2019 to June 2020 on CNCP patients who had previously undergone an opioid deprescription (n = 119 patients). Demographic, clinical (pain, relief and adverse events) and therapeutic (analgesic use) outcomes were collected. Effectiveness (< 50 mg per day of morphine equivalent daily dose without any aberrant opioid use behaviour) and safety (number of side-effects) were analysed in relation to sex differences and pharmacogenetic markers impact [OPRM1 genotype (rs1799971) and CYP2D6 phenotypes]. Long-term opioid deprescription was achieved in 49 % of the patients with an increase in pain relief and a reduction of adverse events. CYP2D6 poor metabolizers showed the lowest long-term opioid doses. Here, women showed a higher degree of opioid deprescription, but increased use of tramadol and neuromodulators, as well as an increased number of adverse events. Long-term deprescription was successful in half of the cases. Understanding sex and gender interaction plus a genetic impact could help to design more individualized strategies for opioid deprescription.