Loading…
Metformin use decreases the anticoagulant effect of phenprocoumon
Summary Background Anticoagulant therapy with vitamin K antagonists (VKAs) is affected by interaction of the VKAs with a large number of other drugs. Although metformin is generally not considered to interact with VKAs, we observed a decrease in INR after starting metformin treatment in patients usi...
Saved in:
Published in: | Journal of thrombosis and haemostasis 2014-06, Vol.12 (6), p.887-890 |
---|---|
Main Authors: | , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | Summary
Background
Anticoagulant therapy with vitamin K antagonists (VKAs) is affected by interaction of the VKAs with a large number of other drugs. Although metformin is generally not considered to interact with VKAs, we observed a decrease in INR after starting metformin treatment in patients using the VKA phenprocoumon.
Objectives
To investigate the influence of metformin use on the dosage of phenprocoumon and INR in stably anticoagulated patients.
Patients
We used the database of the Anticoagulation Clinic Leiden for this study. In a population of 369 patients screened, 27 consecutive patients using phenprocoumon were prescribed metformin during the study period (1 January 2007 to 1 March 2009), without use of other concomitant medications or medical interventions that could influence the INR.
Results
The mean phenprocoumon dosage increased from 2.13 to 2.37 mg per day within 6 weeks (mean increase, 0.23 mg; 95% CI, 0.12–0.34) and 2.49 mg per day within 3 months (mean increase, 0.36 mg; 95% CI, 0.24–0.48) after starting metformin. The mean INR decreased from 2.88 to 2.26 (mean decrease, 0.63; 95% CI, 0.41–0.85) within 6 weeks and 2.54 (mean decrease, 0.35; 95% CI, 0.24–0.48) within 3 months after starting metformin.
Conclusions
This study shows that clinicians should be aware that metformin treatment may lead to an increased optimal dosage of phenprocoumon. |
---|---|
ISSN: | 1538-7933 1538-7836 1538-7836 |
DOI: | 10.1111/jth.12578 |