title: Pharmacokinetics of hydralazine, an antihypertensive and DNA-demethylating agent, using controlled-release formulations designed for use in dosing schedules based on the acetylator phenotype.
abstract: OBJECTIVE
  The antihypertensive hydralazine has recently been repositioned as DNA demethylating for the epigenetic therapy of cancer. As the acetylator phenotype is the key determinant of its plasma levels, the dose of hydralazine needs to be adjusted for the acetylation status of patients.
  
  
  METHODS
  The pharmacokinetics of orally administered hydralazine was evaluated in 26 healthy volunteers (13 slow and 13 fast acetylators) after a single dose of 182 mg administered as a controlled-release tablet. Plasma levels of hydralazine were analyzed in 85 cancer patients treated with this formulation at a dose of 83 mg/day and 182 mg/day for slow and fast acetylators, respectively.
  
  
  RESULTS
  The C(max) and t(max) of hydralazine for fast acetylators were 208.4 ± 56.9 SD ng/ml and 2.8 ± 2.5 h, respectively. The corresponding results for slow acetylators were 470.4 ± 162.8 ng/ml, and 4.4 ± 3.1 h. Healthy volunteers who were fast acetylators had no clinically significant changes in blood pressure and heart rate or any other side-effect, however, slow acetylators had transient episodes of headache, tachycardia and faintness. Among 85 cancer patients that received either 182 mg or 83 mg of hydralazine daily, according to their acetylator status, the mean concentrations of hydralazine in plasma were 239.1 ng/ml and 259.2 ng/ml for fast and slow acetylators, respectively. These differences were not significantly different, p = 0.3868.
  
  
  CONCLUSIONS
  The administration of dose-adjusted controlled-release hydralazine according to the acetylation status of cancer patients yields similar levels of hydralazine.
authors.affiliation: Division of Basic Research, Instituto Nacional de Cancerologia, Estado de México, México.
authors.forename: A
authors.initials: A
authors.lastname: Gonzalez-Fierro
authors.forename: D
authors.initials: D
authors.lastname: Vasquez-Bahena
authors.forename: L
authors.initials: L
authors.lastname: Taja-Chayeb
authors.forename: S
authors.initials: S
authors.lastname: Vidal
authors.forename: C
authors.initials: C
authors.lastname: Trejo-Becerril
authors.forename: E
authors.initials: E
authors.lastname: Pérez-Cardenas
authors.forename: E
authors.initials: E
authors.lastname: de la Cruz-Hernández
authors.forename: A
authors.initials: A
authors.lastname: Chávez-Blanco
authors.forename: O
authors.initials: O
authors.lastname: Gutiérrez
authors.forename: D
authors.initials: D
authors.lastname: Rodriguez
authors.forename: Z
authors.initials: Z
authors.lastname: Fernandez
authors.forename: A
authors.initials: A
authors.lastname: Duenas-González
mesh_terms: D000107:Acetylation; D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics*; D016022:Case-Control Studies; D019175:DNA Methylation / Q000187:drug effects; D003692:Delayed-Action Preparations; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D006830:Hydralazine / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics*; D008297:Male; D009369:Neoplasms / Q000188:drug therapy* / Q000473:pathology; D010641:Phenotype; D013607:Tablets; D055815:Young Adult
chemical_list: D000959:Antihypertensive Agents; D003692:Delayed-Action Preparations; D013607:Tablets; D006830:Hydralazine