title: [Usefulness of the clonidine test for the diagnosis of pheochromocytoma].
abstract: BACKGROUND
  The clonidine test has been proposed as diagnostic biochemical test for patients with clinical suspicion of pheochromocytoma.
  
  
  METHODS
  The clonidine test was used in 80 patients with suspicion of pheochromocytoma (on account of suggestive clinical findings, increased levels of metanephrines, increased plasma or urinary levels of catecholamines, or suggestive images by ultrasonography or CT).
  
  
  RESULTS
  Surgery confirmed the diagnosis of pheochromocytoma in 16 patients. The highest sensitivity (62%) and specificity (46%) of the clonidine test corresponded to a brake degree of 5%, with a predictive negative value of 83%. The test was most useful in patients with increased basal plasma values of catecholamines (sensitivity, 62%; specificity, 66%).
  
  
  CONCLUSIONS
  The clonidine test can be useful for the diagnosis of pheochromocytoma in patients with increased basal plasma levels of catecholamines and a brake degree lower than 5% at 180 minutes.
authors.affiliation: Unidad de Hipertensión Arterial y Lípidos, Servicio de Medicina Interna, Hospital Universitario Virgen de las Nieves, Granada.
authors.forename: J D
authors.initials: JD
authors.lastname: Mediavilla García
authors.forename: L
authors.initials: L
authors.lastname: León-Ruiz
authors.forename: C
authors.initials: C
authors.lastname: Hidalgo Tenorio
authors.forename: M
authors.initials: M
authors.lastname: López de la Torre Casares
authors.forename: G
authors.initials: G
authors.lastname: Piédrola Maroto
authors.forename: P
authors.initials: P
authors.lastname: Pinel Julián
authors.forename: C
authors.initials: C
authors.lastname: Fernández-Torres
authors.forename: J
authors.initials: J
authors.lastname: Jiménez-Alonso
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D000328:Adult; D002395:Catecholamines / Q000097:blood; D003000:Clonidine; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010673:Pheochromocytoma / Q000175:diagnosis* / Q000378:metabolism; D012680:Sensitivity and Specificity
chemical_list: D002395:Catecholamines; D003000:Clonidine