anagrelide

Anagrelide is a prescription medication used to treat essential thrombocythemia by reducing elevated platelet counts and the associated risk of thrombotic events. It acts as a selective inhibitor of megakaryocyte maturation, lowering platelet production through inhibition of phosphodiesterase 3 (PDE3). By increasing cyclic AMP in megakaryocytes, it slows their maturation and platelet release, without broadly cytotoxic effects on mature platelets.

Brand names include Agrylin in the United States and Xagrid in the European Union. It is primarily indicated for adults with essential thrombocythemia who are at risk of thrombosis or who are intolerant to other cytoreductive therapies; in some guidelines, it may be used as second-line therapy.

Dosing and monitoring are individualized. Therapy is typically started at a low dose and titrated gradually to achieve a target platelet count while minimizing side effects. Maintenance doses commonly range from about 0.5 to 2 mg daily, given in divided doses; higher doses are associated with a greater risk of adverse effects. Regular monitoring of platelet counts and cardiovascular status is recommended. Common adverse effects include tachycardia, palpitations, headache, diarrhea, and edema; serious cardiovascular events have been reported, so caution is advised in patients with known heart disease.

Contraindications and precautions include hypersensitivity to the drug. Use in pregnancy is not well established and generally requires risk–benefit consideration. Anagrelide may interact with medications affecting cytochrome P450 pathways, particularly CYP1A2 inhibitors or inducers, and with other drugs influencing cardiovascular or hematologic status, necessitating careful monitoring.