Australia. The Australian Adverse Drug Reactions Advisory Committee (ADRAC) has received 18 reports involving drug interactions between miconazole oral gel (Daktarin oral gel) and warfarin with a resultant increase in INR (International Normalized Ratio) values. In 17 cases this involved a clinically significant increase in INR with values ranging between 7.5 and 18 and occurred within 1-2 weeks of starting miconazole. Withdrawal of one or both drugs was necessary in most cases; at least nine patients required vitamin K and five required treatment with fresh frozen plasma. Since miconazole is available without a prescription, both pharmacists and physicians are reminded to be vigilant to the possibility of such an interaction.

Reference:
Australian Adverse Drug Reactions Bulletin 21:14-15, Dec 2002. Available from URL: http://www.health.gov.au