title: Does gender, food or grapefruit juice alter the pharmacokinetics of primaquine in healthy subjects?
abstract: OBJECTIVE
  To evaluate the effects of gender, food and grapefruit juice on the pharmacokinetics of primaquine in healthy subjects.
  
  
  METHODS
  In a randomized, two-phase cross-over study, 10 male and 10 female healthy Vietnamese subjects were administered 30 mg primaquine in the fasting state or with food, followed by administration of primaquine with grapefruit juice.
  
  
  RESULTS
  The pharmacokinetics of primaquine were comparable between male and female subjects, with geometric mean ratios of Cmax = 0.89 [95% confidence interval (CI) 0.65, 1.22] and AUC = 0.80 (95% CI 0.56, 1.15). The mean CL/F of primaquine was slightly higher in males than in females [0.52 l h(-1) kg(-1)vs. 0.43 l h(-1) kg(-1), mean difference of 0.09 (95% CI -0.10, 0.28), P = 0.32]. When compared with fasting state values, food increased the geometric mean Cmax of primaquine by 26% (95% CI 12, 40) and the AUC by 14% (95% CI 3, 27). Similarly, grapefruit juice increased the geometric mean Cmax by 23% (95% CI 4, 45) and the AUC by 19% (95% CI 4, 37).
  
  
  CONCLUSIONS
  The disposition of primaquine was comparable between genders, suggesting no need to modify the dose of primaquine for malaria treatment or prophylaxis. Food increased the oral bioavailability of primaquine, which may lead to higher antimalarial efficacy. Grapefruit juice increased the bioavailability of primaquine, with marked interindividual differences suggesting that people should not take primaquine with grapefruit juice.
authors.affiliation: Department of Infectious Disease, Central Military Hospital, Hanoi, Vietnam.
authors.forename: Bui Tri
authors.initials: BT
authors.lastname: Cuong
authors.forename: Vu Quoc
authors.initials: VQ
authors.lastname: Binh
authors.forename: Bui
authors.initials: B
authors.lastname: Dai
authors.forename: Dinh Ngoc
authors.initials: DN
authors.lastname: Duy
authors.forename: Claire M
authors.initials: CM
authors.lastname: Lovell
authors.forename: Karl H
authors.initials: KH
authors.lastname: Rieckmann
authors.forename: Michael D
authors.initials: MD
authors.lastname: Edstein
mesh_terms: D000328:Adult; D000962:Antimalarials / Q000493:pharmacokinetics*; D001628:Beverages; D032083:Citrus paradisi; D005260:Female; D018565:Food-Drug Interactions; D006801:Humans; D008297:Male; D011319:Primaquine / Q000493:pharmacokinetics*; D012727:Sex Characteristics
chemical_list: D000962:Antimalarials; D011319:Primaquine