Anagrelide hydrochloride is primarily used to treat thrombocythemia, a condition characterized by an abnormally high number of platelets in the blood. By reducing platelet production, it helps prevent blood clots, which can lead to serious complications such as stroke or heart attack. It is particularly effective for patients with essential thrombocythemia who are at risk of thromboembolic events. The medication is often prescribed when other treatments, like aspirin, are insufficient or unsuitable. It is administered orally and requires careful monitoring of blood counts to ensure optimal dosing and to minimize side effects. Its targeted action on megakaryocytes, the cells responsible for platelet production, makes it a valuable option in managing this condition.