title: Effects of tetracycline on the pharmacokinetics of halofantrine in healthy volunteers.
abstract: OBJECTIVE
  To investigate the effect of tetracycline co-administration on the pharmacokinetics of halofantrine in healthy subjects.
  
  
  METHODS
  Eight healthy males were each given 500 mg single oral doses of halofantrine alone, or with tetracycline (500 mg 12 hourly for 7 days), in a crossover fashion. Blood samples collected at predetermined intervals were analyzed for halofantrine and its major metabolite, desbutylhalofantrine (HFM), using a validated HPLC method.
  
  
  RESULTS
  Co-administration of tetracycline and halofantrine resulted in a significant increase (P < 0.05) in the maximum plasma concentration (C(max)), total area under the concentration-time curve (AUC), and terminal elimination half-life (t(1/2,z)), compared with halofantrine alone. (C(max) 0.43 +/- 0.14 vs 1.06 +/- 0.44 microg ml(-1) (95% CI on the difference 0.30, 0.95); AUC 32.0 +/- 13.6 vs 63.7 +/- 20.1 microg ml(-1) h (95% CI 14.2, 49.1); t(1/2,z:) 90.8 +/- 17.9 vs 157.4 +/- 57.4 h (95% CI 21.7, 111.5)). Similarly, tetracycline caused a significant increase (P < 0.05) in the AUC and C(max) of HFM.
  
  
  CONCLUSIONS
  Tetracycline co-administration significantly increases the plasma concentrations of halofantrine and its major metabolite.
authors.affiliation: Department of Clinical Pharmacology, College of Medicine, University of Maiduguri, Maiduguri, Nigeria.
authors.forename: Peter U
authors.initials: PU
authors.lastname: Bassi
authors.forename: Cyprian O
authors.initials: CO
authors.lastname: Onyeji
authors.forename: Otas E
authors.initials: OE
authors.lastname: Ukponmwan
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000962:Antimalarials / Q000493:pharmacokinetics*; D019540:Area Under Curve; D018592:Cross-Over Studies; D006207:Half-Life; D006801:Humans; D008297:Male; D010616:Phenanthrenes / Q000493:pharmacokinetics*; D013752:Tetracycline / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D000962:Antimalarials; D010616:Phenanthrenes; D013752:Tetracycline; C023768:halofantrine