Answer
Prolonged prothrombin time has been reported in patients taking doxycycline and warfarin; tetracyclines depress plasma prothrombin activity, so reduced doses of concomitant anticoagulants may be necessary.
Sources for this answer
- Vibramycin-D Dispersible Tablets 100mgPfizer Limited · emc · SmPC §4.5 Interaction with other medicinal products · Version 13Document updated
Sources checked