The US Food and Drug Administration (FDA) has issued an urgent warning to doctors after tests on a GlaxoSmithKline (GSK) blood clotting drug revealed potential safety issues.
FDA officials said patients with chronic liver disease-induced thrombocytopenia should not be treated with eltrombopag, marketed by GSK as Promacta, because of suspicions that the treatment could cause an imbalance of thrombosis of the portal venous system.
The claim was made after 6% of patients in a randomised, double-blind, placebo-controlled test experienced a thrombotic event, with five of the six patients in the eltrombopag group doing so at platelet counts above 200,000/muL.
Speaking in the new guidance, GSK and the FDA reminded doctors that eltrombopag should be used only for the treatment of thrombocytopenia in adult patients with idiopathic thrombocytopenic purpura, and not for thrombocytopenia in people with chronic liver disease.
The organisations said the product should also be used to increase, rather than normalise, the platelet count.
Caution should always be exercised when administering the drug to patients with known risk factors for thromboembolism or hepatic disease, the FDA and GSK added.
Copyright Press Association 2010