title: Acute hemodynamic interaction of aspirin and ticlopidine with enalapril: results of a double-blind, randomized comparative trial.
abstract: BACKGROUND
  Coprescription of aspirin and ACE inhibitors is frequent in heart failure caused by coronary artery disease. Negative interaction between aspirin and enalapril has been reported, presumably through inhibition by aspirin of ACE inhibitor-induced prostaglandin synthesis. Ticlopidine is a potent antiplatelet agent without interaction with prostaglandin synthesis.
  
  
  RESULTS
  The objective of this study was to compare the influence of a coadministration of ticlopidine or aspirin on the hemodynamic effects of an ACE inhibitor (enalapril) in patients with chronic heart failure. Twenty patients with severe heart failure were enrolled in a double-blind comparative trial and allocated to ticlopidine (500 mg daily, 12 patients) or aspirin (325 mg daily, 8 patients). Hemodynamic evaluation was performed after 7 days of treatment, every hour for 4 hours after an oral administration of 10 mg of enalapril. Significant reductions in systemic vascular resistance were observed in the ticlopidine group, in contrast to no significant decrease in the aspirin group. A significant (P=0.03) time-by-treatment interaction indicated significant aspirin-enalapril drug interaction. Total pulmonary resistance decreased significantly in both groups, with no difference between patients assigned to aspirin or ticlopidine.
  
  
  CONCLUSIONS
  Enalapril reduced systemic vascular resistance more effectively when given in combination with ticlopidine than with aspirin. In contrast, the reduction in total pulmonary resistance is similar when enalapril is administered in combination with aspirin or ticlopidine. Negative aspirin-enalapril interaction on prostaglandin synthesis presumably alters vasodilatation in systemic vessels, whereas prostaglandin-independent actions of ACE inhibition such as pulmonary arterial vasodilatation are maintained.
authors.affiliation: Department of Cardiology, Cochin Hospital, René Descartes University, Paris, France. christian.spaulding@cch.ap-hop-paris.fr
authors.forename: C
authors.initials: C
authors.lastname: Spaulding
authors.forename: B
authors.initials: B
authors.lastname: Charbonnier
authors.forename: A
authors.initials: A
authors.lastname: Cohen-Solal
authors.forename: Y
authors.initials: Y
authors.lastname: Juillière
authors.forename: E P
authors.initials: EP
authors.lastname: Kromer
authors.forename: K
authors.initials: K
authors.lastname: Benhamda
authors.forename: R
authors.initials: R
authors.lastname: Cador
authors.forename: S
authors.initials: S
authors.lastname: Weber
mesh_terms: D000328:Adult; D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use; D004311:Double-Blind Method; D004656:Enalapril / Q000627:therapeutic use; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D013988:Ticlopidine / Q000627:therapeutic use
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D010975:Platelet Aggregation Inhibitors; D004656:Enalapril; D013988:Ticlopidine; D001241:Aspirin