title: Oral ciprofloxacin affects the pharmacokinetics of paracetamol in saliva.
abstract: BACKGROUND
  To determine whether concomitant administration of ciprofloxacin has any effect on the release and absorption of paracetamol.
  
  
  METHODS
  Ten healthy female volunteers received a single oral dose of paracetamol 1g or paracetamol 1g plus ciprofloxacin 500mg in a double-blind, crossover study. Pharmacokinetic parameters were measured in salivary samples using a colorimetric method.
  
  
  RESULTS
  Maximum paracetamol concentration (C(max)) in saliva was significantly decreased when co-administered with ciprofloxacin (19.50 vs 13.70 microg/mL, p < 0.05). Time to paracetamol C(max) was significantly increased (1.43h vs 0.77h; p < 0.05) and paracetamol half-life was prolonged (1.19 to 1.53h, p = 0.05) in the presence of ciprofloxacin, whereas the area under the concentration-time curve was not affected.
  
  
  CONCLUSIONS
  Concomitant administration of ciprofloxacin with paracetamol may result in a delayed onset of action of paracetamol.
authors.affiliation: Department of Chemistry, Pharmaceutical Analytical Chemistry, Alaqsa University, Gaza, Palestine, Palestine.
authors.forename: Mahmoud Mohamed
authors.initials: MM
authors.lastname: Issa
authors.forename: R'afat Mahmoud
authors.initials: RM
authors.lastname: Nejem
authors.forename: Naser Said
authors.initials: NS
authors.lastname: El-Abadla
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000284:Administration, Oral; D000328:Adult; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage / Q000493:pharmacokinetics; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000493:pharmacokinetics; D019540:Area Under Curve; D002939:Ciprofloxacin / Q000008:administration & dosage / Q000493:pharmacokinetics*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004347:Drug Interactions; D005260:Female; D006207:Half-Life; D006801:Humans; D008657:Metabolic Clearance Rate; D012463:Saliva / Q000378:metabolism*
chemical_list: D018712:Analgesics, Non-Narcotic; D000890:Anti-Infective Agents; D000082:Acetaminophen; D002939:Ciprofloxacin