title: Development of a UPLC-MS/MS method for the quantification of sildenafil by DBS, and its use on pediatric pulmonary hypertension.
abstract: BACKGROUND
  Sildenafil is used for the treatment of pediatric pulmonary hypertension. A dried blood spot (DBS)-based LC-MS method for sildenafil quantitation was developed and applied to a group of patients.
  
  
  RESULTS
  DBS showed high portability and stability of samples, and the method was selective and linear for quantitation of sildenafil (5-3,000 ng/ml) and N-desmethyl-sildenafil (3-1,500 ng/ml). After a single oral dose of sildenafil (1 mg/kg), method evidenced poor metabolism in these patients.
  
  
  CONCLUSIONS
  The method was successfully applied in peripheral blood and can be used for both pharmacokinetics and therapeutic drug monitoring. DBS proved to have advantages during sample translation and preservation of analytes. Data suggest that hazardous blood sildenafil levels may be reached in this population.
authors.affiliation: Escuela Nacional de Ciencias Biológicas (ENCB), Instituto Politécnico Nacional (IPN), Mexico City, Mexico.
authors.forename: Leticia
authors.initials: L
authors.lastname: Contreras Zavala
authors.forename: Liliana
authors.initials: L
authors.lastname: Rivera Espinosa
authors.forename: Alionka P
authors.initials: AP
authors.lastname: Ángeles Moreno
authors.forename: Eduardo
authors.initials: E
authors.lastname: Ramírez San-Juan
authors.forename: Sergio
authors.initials: S
authors.lastname: Zamudio Hernández
authors.forename: Alberto
authors.initials: A
authors.lastname: García González
authors.forename: Gabriel
authors.initials: G
authors.lastname: Marcelín Jiménez
mesh_terms: D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D059788:Dried Blood Spot Testing; D016903:Drug Monitoring; D005260:Female; D006207:Half-Life; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy; D008297:Male; D010879:Piperazines / Q000097:blood* / Q000493:pharmacokinetics / Q000627:therapeutic use; D011687:Purines / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use; D000068677:Sildenafil Citrate; D013449:Sulfonamides / Q000097:blood* / Q000493:pharmacokinetics / Q000627:therapeutic use; D053719:Tandem Mass Spectrometry; D014665:Vasodilator Agents / Q000097:blood* / Q000493:pharmacokinetics / Q000627:therapeutic use
chemical_list: D010879:Piperazines; D011687:Purines; D013449:Sulfonamides; D014665:Vasodilator Agents; D000068677:Sildenafil Citrate