Clinical Trials Directory

Trials / Completed

CompletedNCT01104337

Drug Interaction Between Paracetamol and Warfarin

Dose-dependent Drug-drug Interaction Between Paracetamol and Warfarin in Adults Receiving Long-term Oral Anticoagulants: A Randomized Controlled Trial

Status
Completed
Phase
Phase 4
Study type
Interventional
Enrollment
45 (actual)
Sponsor
Hopital Lariboisière · Academic / Other
Sex
All
Age
18 Years
Healthy volunteers
Not accepted

Summary

The objective of this study is to investigate whether paracetamol, given at therapeutic doses (2g/day and 3 g/day), may potentiate the anticoagulant effect of warfarin.

Detailed description

Paracetamol is recommended as a first-line analgesic and antipyretic therapy in patients receiving short- and long-term oral anticoagulation, especially elderly patient.However,Increased INR was previously observed in patients treated with warfarin and paracetamol given at the maximum recommended dose (4g/day). To date, the mechanism of this interaction has not been determined.A recent in vitro study suggested that the toxic metabolite N-acetyl-para-benzoquinoneimine (NAPQI) appeared to interfere with vitamin K-dependent γ-carboxylase (VKD-carb) and vitamin K epoxide reductase (VKOR) activites12. The question remaining to be dealt with is whether this in vitro observation can explain the in vivo paracetamol-warfarin interaction. We aim to evaluate the effect of paracetamol at the most widely used doses 2 and 3g/day on INR in stable patients treated with warfarin in a double blind randomized placebo-controlled trial and to identify the mechanism involved in this interaction in vivo.

Conditions

Interventions

TypeNameDescription
DRUGparacetamolTreatment consisted of two paracetamol 500mg (Doliprane® 500mg, Sanofi-aventis, Paris, France) tablets twice a day along with two matching placebo tablets once daily
DRUGparacetamolTreatment consisted of two paracetamol 500mg (Doliprane® 500mg, Sanofi-aventis, Paris, France) tablets three times a day
DRUGPlaceboTreatment consisted of two matching placebo tablets three times a day.

Timeline

Start date
2007-03-01
Primary completion
2008-11-01
Completion
2010-02-01
First posted
2010-04-15
Last updated
2010-04-15

Locations

1 site across 1 country: France

Source: ClinicalTrials.gov record NCT01104337. Inclusion in this directory is not an endorsement.