title: [Prevalence of Avoidable Potential Interactions Between Antidepressants and Other Drugs in Colombian Patients].
abstract: OBJECTIVE
  To determine the possible drugs interactions with antidepressive agents in data bases of patients in the Health Insurance System of Colombia.
  
  
  METHODS
  From data bases of about 4 million users in Colombia, a systematic review of drugs dispensation statistics was made to identify drug interactions between antidepressive agents, cholinergic antagonists and tramadol in 2010.
  
  
  RESULTS
  We identified 114,465 monthly users of antidepressive agents. Of these, 5776 (5.0%) received two, and 178 (0.2%) received three antidepressive agents simultaneously. The most frequent combination was fluoxetine+trazodone (n=3235; 56.9% of cases). About 1127 (1.0%) patients were prescribed a cholinergic antagonist simultaneously; 2523 (2.1%) users were dispensed tramadol at the same time, while raising the risk of serotonin syndrome.
  
  
  CONCLUSIONS
  Drug interactions represent a potential risk that is often underestimated by physicians. Pharmacovigilance is a useful tool to optimize resources and prevent negative outcomes associated with medication. It is recommended that systematic search is made to enhance surveillance programs for the rational use of medicines in this country.
authors.affiliation: Grupo de Investigación en Farmacoepidemiología y Farmacovigilancia, Departamento de Ciencias Básicas, Facultad de Ciencias de la Salud, Universidad Tecnológica de Pereira, Pereira, Colombia; Departamento de Farmacoepidemiología, Audifarma S.A., Pereira, Colombia. Electronic address: machado@utp.edu.co.
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Machado-Alba
authors.affiliation: Grupo de Investigación en Farmacoepidemiología y Farmacovigilancia, Departamento de Ciencias Básicas, Facultad de Ciencias de la Salud, Universidad Tecnológica de Pereira, Pereira, Colombia.
authors.forename: Cristhian David
authors.initials: CD
authors.lastname: Morales-Plaza
keywords: Adverse drug reaction; Agentes antidepresivos; Amitriptilina; Amitriptyline; Antagonistas colinérgicos; Antidepressive agents; Cholinergic antagonists; Colombia; Drug prescriptions; Farmacovigilancia; Fluoxetina; Fluoxetine; Pharmacovigilance; Prescripciones de medicamentos; Reacción adversa medicamentosa; Tramadol; Trazodona; Trazodone