Joseph P. Rindone* and Chadwick K. Mellen Pages 141 - 143 ( 3 )
Background: Salsalate may offer many advantages over other non-steroidal antiinflammatory agents in patients taking warfarin, however a drug-drug interaction may occur which has not been reported in the medical literature or by the manufacturer of salsalate.
Objective: To report a case of warfarin potentiation associated with salsalate treatment, which resulted in bleeding.
Method: Clinical review of the course of a patient, who was stable on warfarin when salsalate therapy was added for chronic pain.
Case Report: A patient taking stable doses of warfarin for over 1 year (with good control) was prescribed salsalate 3 g/day for pain in his knee and lower back. Approximately 1 month later he presents to the anticoagulation clinic with bruising and an International Normalized Ratio (INR) of 6.8. The patient had a good response to his salsalate therapy and wanted to continue it. The warfarin was held for 3 days and dose lowered by 50 %. His bruising then subsided and he had good control of his warfarin therapy with INRs ranging from 1.9 to 2.2 over the next 4 months. The patient was then lost to follow up.
Conclusion: This case illustrates a strong association between starting salsalate and subsequent potentiation of warfarin, which heretofore has not been reported in the medical literature.
Warfarin, salsalate therapy, interaction, INR, NSAIDS, antibiotic.
Clinical Pharmacy Section, Northern Arizona VA Health Care System, Hwy 89, Prescott, AZ 86313, Clinical Pharmacy Section, Northern Arizona VA Health Care System, Hwy 89, Prescott, AZ 86313