title: A systematic review of the influence of opioids on advanced cancer patient survival.
abstract: OBJECTIVE
  Many health professionals still believe that opioids shorten the lifespan of patients. This situation implies that the ethical doctrine of double effect is often invoked to justify their use in extreme circumstances. The objective of this study is to revise the evidence existing in the recently published literature regarding the effect on patient survival of opioid used to control disease symptoms.
  
  
  RESULTS
  A review of the scientific literature regarding the effects of opioids on symptom control and survival does not provide any evidence that there is an association between these two variables.
  
  
  CONCLUSIONS
  The studies revised have not shown that the use of opioids for symptom control in advanced disease stages or in the last days of life has any effect on patient survival. Similarly, survival was not influenced by either the use of higher or lower doses of opioids, or by the practice of administering a double dose at night.
authors.affiliation: aPalliative Care Unit, Clinic University of Navarra bUniversity of Navarra, Institute for Culture and Society (ICS), ATLANTES Research Program: Human Dignity, Advance Disease and Palliative Care cBiomedical Humanities Department, Navarra University, Pamplona, Spain.
authors.forename: José Mario
authors.initials: JM
authors.lastname: López-Saca
authors.forename: José López
authors.initials: JL
authors.lastname: Guzmán
authors.forename: Carlos
authors.initials: C
authors.lastname: Centeno
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D001291:Attitude of Health Personnel; D006801:Humans; D033182:Intention; D009020:Morphine / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D009369:Neoplasms / Q000150:complications* / Q000188:drug therapy / Q000401:mortality; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D059408:Pain Management / Q000941:ethics* / Q000379:methods / Q000401:mortality; D010166:Palliative Care / Q000379:methods*; D016019:Survival Analysis
chemical_list: D000701:Analgesics, Opioid; D009020:Morphine