Certain pain medications increase the risk of bleeding in patients on warfarin (coumadin®, Jantoven). Two mechanism can be at play: (1) non-steroidal pain medications (NSAIDs = non-steroidal anti-inflammatory drugs) may lead to gastritis which can lead to bleeding into the stomach, made worse by being on “blood thinners”, and (2) pain medications taken on a regular basis may interfere with warfarin, leading to an increase in INR, increasing the risk for bleeding.
The table below lists oral pain medications that do not increase the risk for bleeding in patients on anticoagulants if taken occasionally (PRN), as they are not NSAIDs. They can also be taken on a regular basis, but in that case an INR should be checked about 4-5 days after starting the drug, and again about 10 days later, to make sure that there has not been an interaction of the newly taken regular pain medication on warfarin metabolism and the INR.
Table. Safe pain medication options in the patient on “blood thinners
| Generic name | Brand name, examples | |
| Weaker pain medication | Acetaminophen | Tylenol |
| Intermediate strength pain medications | Tramadol | Ultram, Ultracet |
| Codeine sulfate | ||
| Hydrocodone | Lorcet, Lortab, Vicodin | |
| Stronger pain medications | Hydromorphone | Dilaudid |
| Meperidine | Demerol | |
| Morphine | MS Contin | |
| Oxycodone | Percocet |
Disclosure: I have no financial conflict of interest to this blog entry.
Last updated: Nov 30th, 2010

2 responses to “Safe Pain Medications on Warfarin”
Please comment on use of topical NSAIDs by patients on warfarin.
Although topical non-steroidal anti-inflammatory drugs (NSAIDs) are safer than oral NSAIDs (fewer severe gastrointestinal adverse events), a substantial proportion of adults report systemic adverse events with topical agents (ref 1). This may well be due to the fact that some of the NSAIDs applied to the skin are absorbed into the blood stream (ref 2). In reference 1, five cases of warfarin potentiation with topical agents were reported, one of which resulted in gastrointestinal bleeding (ref 1). These data suggest that patients on warfarin talking topical NSAIDs on a regular basis should be aware that there may be an increased risk of bleeding, as well as an impact of the topical NSAIDs on the INR.
References
1. Markis UE et al. Adverse Effects of Topical Nonsteroidal Antiinflammatory Drugs in Older Adults with Osteoarthritis: A Systematic Literature Review. J Rheumatol 2010;37:1236–43.
2. Roberts MS et al. Percutaneous absorption of topically applied NSAIDS and other compounds: role of solute properties, skin physiology and delivery systems. Inflammopharmacology.1999;7(4):339-50