Rybix ODT and Warfarin

In the database of official manuals used in the service creation an interaction registered by statistical results of studies was found, which can either lead to negative consequences for the patient health or strengthen a mutual positive effect. A doctor should be consulted to address the issue of joint drug administration.

Using warfarin together with traMADol may cause you to bleed more easily. You may need a dose adjustment based on your prothrombin time or International Normalized Ratio (INR). Call your doctor promptly if you have any unusual bleeding or bruising, vomiting, blood in your urine or stools, headache, dizziness, or weakness. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

MONITOR: Coadministration with tramadol may potentiate the hypoprothrombinemic effect of warfarin. There have been rare reports of elevated prothrombin time or INR and bleeding in warfarin patients taking tramadol, and a return to normal anticoagulation following its discontinuation. The exact mechanism is unknown but may be related to reduced activity of CYP450 2D6, which can lead to increased plasma concentrations of tramadol. In a retrospective analysis of 17 cases of suspected interaction between tramadol and warfarin that were reported to the Swedish Adverse Drug Reactions Advisory Committee between 1995 and 2003, INR increases were observed between 1.5 to 60 days following initiation of tramadol therapy (mean 13 days). The recorded INR values ranged from 3.4 to greater than 8.5, and bleeding complications occurred in 6 patients (35%). In cases where follow-up information was available, INR values decreased within 1 to 11 days following tramadol withdrawal. In ten cases where genotypes were available for known polymorphisms of several CYP450 isoenzymes that are associated with reduced or absent enzyme activities, seven patients were found to carry a defective CYP450 2D6 allele. A further patient received concomitant drug treatments that may have resulted in CYP450 2D6 inhibition. Although not statistically significant, this finding suggests a higher prevalence of defective alleles compared to the general Swedish population average of 42.2%.

MANAGEMENT: Given the potential for interaction and the high degree of interpatient variability with respect to warfarin metabolism, patients should be closely monitored during concomitant therapy with tramadol. The INR should be checked frequently and warfarin dosage adjusted accordingly, particularly following initiation, discontinuation or change of dosage of tramadol in patients who are stabilized on their warfarin regimen. The same precaution may be applicable during therapy with other oral anticoagulants, although clinical data are lacking. Patients should be advised to promptly report any signs of bleeding to their physician, including pain, swelling, headache, dizziness, weakness, prolonged bleeding from cuts, increased menstrual flow, vaginal bleeding, nosebleeds, bleeding of gums from brushing, unusual bleeding or bruising, red or brown urine, or red or black stools.

Rybix ODT

Generic Name: tramadol

Brand name: ConZip, Ultram, Ultram ER, Rybix ODT, Ryzolt

Synonyms: Rybix ODT (Oral)

What is Rybix ODT?

Warfarin

Generic Name: warfarin

Brand name: Coumadin, Jantoven

Synonyms: n.a.

What is Warfarin?