Coumadin and Ketek

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 telithromycin 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 telithromycin may infrequently enhance the hypoprothrombinemic effect of warfarin. The exact mechanism of interaction is unknown. Although telithromycin is a potent inhibitor of CYP450 3A4 and can inhibit metabolism of the R(+) enantiomer of warfarin, the overall effect on racemic warfarin pharmacokinetics appears to be minor. According to the product labeling, no pharmacodynamic or pharmacokinetic effects on racemic warfarin were observed when telithromycin was coadministered in healthy subjects. Nevertheless, a case report describes a 73-year-old man stabilized on warfarin who developed an increased INR (from 3.1 to 11) and mild hemoptysis five days after starting telithromycin 800 mg/day. The INR returned to the therapeutic range 4 days after telithromycin was discontinued.

MANAGEMENT: Given the potential for clinically significant interaction in the occasional, susceptible patient, close monitoring is recommended if telithromycin is prescribed during warfarin therapy. The INR should be checked frequently and coumarin dosage adjusted accordingly, particularly following initiation or discontinuation of telithromycin therapy in patients who are stabilized on their anticoagulant regimen. 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. The same precaution may be applicable during therapy with other oral anticoagulants, although clinical data are lacking.

Coumadin

Generic Name: warfarin

Brand name: Coumadin, Jantoven

Synonyms: n.a.

What is Coumadin?

Ketek

Generic Name: telithromycin

Brand name: Ketek

Synonyms: n.a.

What is Ketek?