title: Food effects on the pharmacokinetics of doxylamine hydrogen succinate 25 mg film-coated tablets: a single-dose, randomized, two-period crossover study in healthy volunteers.
abstract: BACKGROUND
  Doxylamine succinate, an ethanolamine-based antihistamine, is used in the short-term management of insomnia because of its sedative effects. The data available on the pharmacokinetic profile of doxylamine in humans are limited, notwithstanding that this drug has been marketed in European countries for more than 50 years. In fact, no data on the effect of food on the pharmacokinetic parameters of doxylamine are available.
  
  
  OBJECTIVE
  The objective of this study was to evaluate the pharmacokinetic parameters of doxylamine following a single oral dose of doxylamine hydrogen succinate 25 mg in healthy human subjects under fed and fasting conditions.
  
  
  METHODS
  This was a single-center, randomized, single-dose, laboratory-blinded, two-period, two-sequence, crossover study.
  
  
  METHODS
  The study was conducted in a phase I clinical unit.
  
  
  METHODS
  A single oral dose of doxylamine hydrogen succinate 25 mg (equivalent to 17.4 mg of doxylamine base) was administered to healthy volunteers under either fed conditions (high-fat, high-calorie food intake) or fasting conditions in each study period. The drug administrations were separated by a wash-out period of seven calendar days. Plasma samples were collected for up to 60 hours postdose, and plasma doxylamine concentrations were determined by a high-performance liquid chromatography method with tandem mass spectrometry detection. Pharmacokinetic parameters were calculated using noncompartmental analysis. Safety was evaluated through assessment of adverse events, standard laboratory evaluations, vital signs, and 12-lead electrocardiography.
  
  
  RESULTS
  In total, 24 healthy subjects (12 male and 12 female) were included in the study. Doxylamine succinate 25 mg tablets exhibited similar oral bioavailability of doxylamine in the fasting state (mean maximum plasma drug concentration [C(max)] 118.21 ng/mL, coefficient of variation [CV] 19.2%; mean area under the plasma concentration time curve from time zero to time t [AUC(t)] 1746.97 ng · h/mL, CV 31.6%) and in the fed state (mean C(max) 120.99 ng/mL, CV 15.0%; mean AUC(t) 1712.20 ng · h/mL, CV 26.7%). No statistically significant between-treatment differences were observed for any of the pharmacokinetic parameters under study. The fed : fasting ratios of the geometric least squares means with corresponding 90% confidence intervals for C(max) and AUC(t) were within the range of 80-125%.
  
  
  CONCLUSIONS
  High-fat, high-calorie food intake does not affect the kinetics of doxylamine in healthy subjects. The drug was safe and well tolerated by the subjects in this study.
authors.affiliation: Clinical Investigation, Laboratorios del Dr. Esteve SA, Barcelona, Spain.
authors.forename: Sebastián
authors.initials: S
authors.lastname: Videla
authors.forename: Mounia
authors.initials: M
authors.lastname: Lahjou
authors.forename: Pascal
authors.initials: P
authors.lastname: Guibord
authors.forename: Zhengguo
authors.initials: Z
authors.lastname: Xu
authors.forename: Carles
authors.initials: C
authors.lastname: Tolrà
authors.forename: Gregorio
authors.initials: G
authors.lastname: Encina
authors.forename: Eric
authors.initials: E
authors.lastname: Sicard
authors.forename: Artur
authors.initials: A
authors.lastname: Sans
mesh_terms: D000284:Administration, Oral; D000328:Adult; D019540:Area Under Curve; D001682:Biological Availability; D018592:Cross-Over Studies; D004319:Doxylamine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D005215:Fasting / Q000378:metabolism; D005260:Female; D018565:Food-Drug Interactions; D006207:Half-Life; D006801:Humans; D008297:Male; D008875:Middle Aged; D013607:Tablets / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics*; D013608:Tablets, Enteric-Coated; D055815:Young Adult
chemical_list: D013607:Tablets; D013608:Tablets, Enteric-Coated; D004319:Doxylamine; C035385:doxylamine succinate