Probable interaction between warfarin and a toothache solution containing Piper longum L. leading to ischemic stroke: a case report.

ETHNOPHARMACOLOGICAL RELEVANCE: Both warfarin and Chinese patent medicine (CPM) are frequently prescribed medications that may have a potential interaction that can go unnoticed.

AIM OF THE STUDY: To report a clinical case of a probable interaction between warfarin and a toothache solution containing Piper longum L., which led to ischemic stroke.

MATERIALS AND

METHODS

We collected data on the clinical case of acute ischemic stroke involving warfarin and the suspected drugs. We performed drug interaction assessment using the Lexicomp® Online™ database and literature search. The Drug Interaction Probability Scale (DIPS) was used to assess the causal relationship between potential drug interactions and the occurrence of ischemic stroke.

RESULTS

Fluctuations in the international normalized ratio (INR) were accompanied by ischemic stroke in a patient with a mechanical heart valve taking warfarin. Causal assessment showed a probable interaction between the interaction of warfarin and a toothache solution containing Piper longum and the ischemic stroke.

CONCLUSIONS

The potential interaction between warfarin and Piper longum should be recognized to prevent adverse outcomes in patients receiving warfarin therapy.