Development of ximelagatran (Exanta),an oral direct thrombin inhibitor,has been stopped in the United States.The drug, which held promise as areplacement for warfarin in manypatients, also will be withdrawn from themarket in Europe and South America.
The withdrawal was prompted bynew reports of serious liver injury notedin the EXTEND clinical trial. This trial studiedthe use of the drug for venous thromboembolismprophylaxis in orthopedicsurgery patients for up to 35 days postoperatively.Reversible elevations in liverfunction tests (LFTs) had been noted inshort-term trials, prompting AstraZenecato recommend regular LFT monitoringduring treatment.
Signs and symptoms of liver injurybegan in the weeks following theend of 35 days of treatment in thelong-term trial. The results suggestedthat recommended monitoring ofliver function during therapy mightnot be enough to eliminate the riskof liver injury.
Dr. Garrett is a clinical pharmacist practitionerat Cornerstone Health Care in HighPoint, NC.