Anagrelide (Agrylin) is a thrombocytopenic agent primarily used for the treatment of thrombocythemia secondary to myeloproliferative neoplasms. It can reduce platelet count, lower the risk of thrombosis, and improve related symptoms. As a special medication, special attention must be paid to multiple considerations during its use, and thorough medication monitoring should be conducted.

Precautions for Anagrelide (Agrylin) Administration

Cardiovascular System Risks

Anagrelide may cause cardiovascular toxic reactions such as QT interval prolongation and ventricular tachycardia.

Before initiating treatment, all patients should undergo a cardiovascular assessment including an electrocardiogram (ECG).

During treatment, regular monitoring of cardiovascular effects is required. Particularly, the drug should be avoided in patients with known risk factors for QT interval prolongation, such as congenital long QT syndrome, a known history of acquired QTc prolongation, use of drugs that can prolong the QT interval, and patients with hypokalemia.

Risk of Pulmonary Hypertension

Cases of pulmonary hypertension have been reported during the use of anagrelide.

Before starting treatment and during treatment, the patient's potential signs and symptoms of cardiopulmonary disease should be evaluated.

If progressive dyspnea accompanied by pulmonary infiltrates occurs, the possibility of interstitial lung disease should be considered; discontinuation of the drug and further evaluation may be necessary.

Bleeding Risk

Concomitant use of anagrelide and aspirin may increase the risk of major bleeding events.

When considering combined use, the potential risks and benefits must be weighed, especially in patients at high risk of bleeding.

Close monitoring is also required when using other drugs known to increase the risk of bleeding (e.g., anticoagulants, PDE3 inhibitors, nonsteroidal anti-inflammatory drugs, antiplatelet drugs, selective serotonin reuptake inhibitors).

Administration in Patients with Hepatic Impairment

The liver is the main organ responsible for the clearance of anagrelide.

Patients with moderate hepatic impairment have an 8-fold increase in anagrelide exposure. Such patients should start treatment at a dose of 0.5 mg per day and undergo frequent monitoring for cardiovascular events.

Patients with severe hepatic impairment should avoid using anagrelide. For patients with mild to moderate hepatic impairment, the potential risks and benefits should be evaluated before initiating treatment.

Medication Monitoring for Anagrelide (Agrylin)

Platelet Count Monitoring

To prevent the occurrence of thrombocytopenia, platelet count should be monitored every two days during the first week of treatment, and then at least once a week until a maintenance dose is achieved.

A platelet count response typically begins within 7-14 days at an appropriate dose.

A complete response (platelet count ≤ 600,000/µL) usually takes 4-12 weeks.

If treatment is interrupted or discontinued, the platelet count usually starts to rise within 4 days and returns to baseline levels within 1-2 weeks, and may rebound above the baseline value. Therefore, frequent monitoring is required.

Cardiovascular Monitoring

During treatment, regular ECG monitoring should be performed, especially in patients with heart failure, bradycardia, or electrolyte abnormalities.

Attention should be paid to monitoring changes in heart rate, as anagrelide can cause a dose-dependent increase in heart rate.

Blood pressure should be monitored, as anagrelide may cause vasodilation and orthostatic hypotension.