title: [Clinical experience in opioid switch for noncancer chronic pain treatment].
abstract: BACKGROUND
  The implementation of opioid switch (OS) as a strategy in non-malignant chronic pain has been scarcely proved. This article aims to evaluate the results of OS in a Pain Treatment Unit.
  
  
  METHODS
  This is an observational retrospective study in which all patients who had been subjeted to OS for a period of 18 months were selected. All of them had been treated with opiods plus adyuvants for more than 6 months and had a visual analog scale (VAS) of at least 5, either with or without adverse effects. Two variables were defined: clinical improvement, as a reduction equal or superior to 3 in VAS or the elimination of two or more adverse effects; equianalgesic dose reduction is the difference between initial and final opioid dose.
  
  
  RESULTS
  7 out of 9 (77%) patients showed clinical improvement. Median equianalgesic dose reduction was 37% (-72% +18%). Five patients (55%) presented adverse effects to opioids before the OS but only one (11%) after OS.
  
  
  CONCLUSIONS
  OS was beneficial for the management of non-malignant chronic pain patients who have poor response to opioid treatment and/or with adverse effects. A secure OS should include a reduction in equianalgesic opioid dose. Prospective studys would achieve a mayor consensus for the applicance of OS in non-malignant chronic pain treatment.
authors.affiliation: Servicio de Farmacia. Consorcio Hospital General Universitario de Valencia.. lopez_frapera@gva.es.
authors.forename: F J
authors.initials: FJ
authors.lastname: López-Pérez
authors.affiliation: Servicio de Farmacia. Consorcio Hospital General Universitario de Valencia.. minguez_ana@gva.es.
authors.forename: A
authors.initials: A
authors.lastname: Mínguez-Martí
authors.affiliation: Unidad del dolor. Servicio de Anestesia, Reanimación y Tratamiento del Dolor. Consorcio Hospital General Universitario de Valencia. España.. estefaniavicario@gmail.com.
authors.forename: E
authors.initials: E
authors.lastname: Vicario-Sánchez
authors.affiliation: Servicio de Farmacia. Consorcio Hospital General Universitario de Valencia.. alpascle@hotmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Pastor-Clérigues
authors.affiliation: Servicio de Farmacia. Consorcio Hospital General Universitario de Valencia.. sanfeliu_joa@gva.es.
authors.forename: J
authors.initials: J
authors.lastname: Sanfeliu-García
authors.affiliation: Servicio de Farmacia. Consorcio Hospital General Universitario de Valencia.. ortega_mpi@gva.es.
authors.forename: M P
authors.initials: MP
authors.lastname: Ortega-García
mesh_terms: D000277:Adjuvants, Pharmaceutic / Q000627:therapeutic use; D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D015360:Analgesia, Epidural; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D023341:Chills / Q000139:chemically induced; D059350:Chronic Pain / Q000188:drug therapy*; D003248:Constipation / Q000139:chemically induced; D057915:Drug Substitution; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage / Q000627:therapeutic use; D006801:Humans; D004091:Hydromorphone / Q000008:administration & dosage / Q000627:therapeutic use; D007263:Infusions, Parenteral; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage / Q000627:therapeutic use; D012189:Retrospective Studies; D013810:Therapeutic Equivalency; D057968:Transdermal Patch; D064232:Visual Analog Scale
chemical_list: D000277:Adjuvants, Pharmaceutic; D000701:Analgesics, Opioid; D009020:Morphine; D004091:Hydromorphone; D005283:Fentanyl