title: Effects of ethanol on intestinal absorption of drugs: in situ studies with ciprofloxacin analogs in acute and chronic alcohol-fed rats.
abstract: BACKGROUND
  Previous work from our laboratory on the effect, in rats, of chronic ethanol intake on the intestinal absorption of ciprofloxacin analogs suggested an increased polarity of the lipoidal membrane constituents without effects on the aqueous environment. The aim of the present study was to investigate the influence of acute ethanol intake on the absorption of the same series of compounds.
  
  
  METHODS
  The effects of in situ ethanol exposure on intestinal absorption were determined in rats fed either a standard liquid diet or a 5% (w/v) ethanol-containing liquid diet. Acute intestinal exposure to 5% (w/v) ethanol was performed in situ in each feeding group. The biophysical absorption model was used to establish correlations between the actual absorption rate constants, and the lipophilicity indexes, for each group of rats.
  
  
  RESULTS
  Acute exposure to ethanol produces an increase only in the absorption of hydrophilic homologs in both control and chronic ethanol fed groups. This suggests the absence of homeoviscous adaptation of the intestinal membrane. The biophysical model used allows us to discriminate between the effects of acute and chronic ethanol treatment on the intestinal membrane.
  
  
  CONCLUSIONS
  These results suggest that in contrast to previous reports chronic ethanol treatment increases membrane polarity and acute alcohol intake appears to modify membrane fluidity.
authors.affiliation: Departamento de Farmacia y Tecnología Farmacéutica, Universidad de Valencia, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Ferrando
authors.forename: T M
authors.initials: TM
authors.lastname: Garrigues
authors.forename: M V
authors.initials: MV
authors.lastname: Bermejo
authors.forename: R
authors.initials: R
authors.lastname: Martín-Algarra
authors.forename: V
authors.initials: V
authors.lastname: Merino
authors.forename: A
authors.initials: A
authors.lastname: Polache
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000493:pharmacokinetics*; D002492:Central Nervous System Depressants / Q000008:administration & dosage*; D002939:Ciprofloxacin / Q000031:analogs & derivatives / Q000493:pharmacokinetics*; D000431:Ethanol / Q000008:administration & dosage*; D007408:Intestinal Absorption / Q000187:drug effects*; D008297:Male; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000890:Anti-Infective Agents; D002492:Central Nervous System Depressants; D000431:Ethanol; D002939:Ciprofloxacin