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London: BMJ Publishing Group and Pharmaceutical Press; 2014

Warfarin and drug interactions: prescribing vigilance

From Volume 43, Issue 1, January 2016 | Pages 34-36

Authors

J Hook

BDS(Hons), MFDS RCSEd

Clinical Teacher, School of Dentistry, The University of Liverpool

Articles by J Hook

Lynne Millsopp

MPhil, BDS, MFDS RCSEd

Senior Lecturer, School of Dentistry, The University of Liverpool

Articles by Lynne Millsopp

E Anne Field

MDS, FDS RCS, DDSci

Consultant and Honorary Professor of Oral Medicine, Liverpool University Dental Hospital, Liverpool, UK

Articles by E Anne Field

Abstract

A patient taking warfarin presented to the Oral Medicine Clinic at Liverpool University Dental Hospital, having been prescribed metronidazole and miconazole by his general dental practitioner (GDP) for his oral mucosal problem. He subsequently developed bruising on his torso following mild trauma. Having read the drug information leaflet provided with his metronidazole and miconazole, he noted the potential drug interactions between these and warfarin. He therefore stopped his warfarin. The details of this case are outlined, and the potential for significant drug interactions with warfarin are highlighted. The need for dental practitioners to be vigilant concerning drug interactions is emphasized, together with the importance of CPD in relation to drug prescribing.

CPD/Clinical Relevance: This case report, which is of relevance to all dental practitioners, highlights the importance of up-to-date medical and drug histories and the continuing awareness of potential drug interactions. In this case, patient intervention after checking drug information leaflets prevented serious consequences. The importance and potentially serious consequences of significant drug interactions needs to be understood.

Article

A 68-year-old male attended the Oral Medicine Department of the Liverpool University Dental Hospital. The patient had been referred by his GDP regarding ‘soreness of the gums and roof of mouth’.

The patient's complaint was of a sore mouth that made it difficult to eat and brush his teeth; this had been present for approximately three months and affected his palate, tongue and inside his cheeks. His GDP had prescribed metronidazole and miconazole for symptomatic relief of his oral symptoms and then referred the patient to the Oral Medicine Department for specialist management.

During the initial consultation the patient also mentioned having bumped into the cooker three evenings ago which had left him with a large bruise on the right side of his stomach. The patient had read the information leaflet supplied with the miconazole and metronidazole and had seen that there was a potential interaction with his warfarin. He had therefore stopped taking his warfarin medication. The patient felt that his dentist would have wanted him to continue with the medications for his sore mouth and that it was the warfarin that needed to be discontinued.

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