Information about Anagrelide
Anagrelide is an antithrombotic and platelet reducing agent that is used to treat the thrombocythemia associated with myeloproliferative diseases.
Liver safety of Anagrelide
Anagrelide has had limited clinical use, but has not been linked to significant serum enzyme elevations during therapy or to instances of clinically apparent acute liver injury.
Mechanism of action of Anagrelide
Anagrelide (an ag' re lide) is platelet reducing agent that is used to treat thrombocytosis due to myeloproliferative diseases. Its mechanism of action is not well defined, but it appears to inhibit the maturation and differentiation of megakaryocytes, and both synthesis and release of platelets as well as subsequent platelet aggregation. In addition, anagrelide inhibits phosphodiesterase-3 which causes vasodilation and may account for many of its side effects. In several open label trials, anagrelide was shown to reduce platelet counts in patients with thrombocythemia due to essential thrombocytosis and other myeloproliferative diseases. Severe thrombocythemia is associated with an increased risk of arterial and venous thromboses including transient ischemic attacks, stroke, myocardial infarction and other thrombotic ischemic conditions. Less commonly, thrombocytosis is associated with venous thromboses including deep vein thrombosis, pulmonary embolus and portal or splanchnic vein thrombosis.
FDA approval information for Anagrelide
Anagrelide was approved for use in thrombocythemia due to myeloproliferative diseases in 1997, but is considered a second line agent, appearing to be less effective and less well tolerated than hydroxyurea. Anagrelide is available in capsules of 0.5 mg generically and under the brand name Agrylin. The typical initial dose is 0.5 mg daily, with subsequent gradual and monitored dose escalation based upon platelet counts and tolerance, not to exceed 10 mg daily or 2.5 mg in a single dose. It is often given in combination with aspirin.
Side effects of Anagrelide
Side effects can include headache, dizziness, palpitations, fatigue, nausea, abdominal pain, dyspnea, cough, fever, edema, rash, chest pain and tachycardia. Rare, but potentially severe adverse reactions include arrhythmias, prolongation of the QTc interval, excessive bleeding and interstitial nephritis.