warnings and cautions
5 WARNINGS AND PRECAUTIONS Cardiovascular Toxicity: QT prolongation and ventricular tachycardia have been reported with anagrelide. Obtain a pre-treatment cardiovascular examination including an ECG in all patients. Monitor patients for cardiovascular effects. ( 5.1 ) Pulmonary Hypertension: Assess underlying cardiopulmonary disease prior to initiating therapy. ( 5.2 ) Bleeding Risk: Monitor patients for bleeding, including those receiving concomitant therapy with other drugs known to cause bleeding. ( 5.3 ) 5.1 Cardiovascular Toxicity Torsades de pointes and ventricular tachycardia have been reported with anagrelide. Obtain a pre-treatment cardiovascular examination including an ECG in all patients. During treatment with anagrelide monitor patients for cardiovascular effects and evaluate as necessary. Anagrelide increases the QTc interval of the electrocardiogram and increases the heart rate in healthy volunteers [see Clinical Pharmacology ( 12.2 )] . Do not use anagrelide in patients with known risk factors for QT interval prolongation, such as congenital long QT syndrome, a known history of acquired QTc prolongation, medicinal products that can prolong QTc interval and hypokalemia [see Drug Interactions ( 7.1 )] . Hepatic impairment increases anagrelide exposure and could increase the risk of QTc prolongation. Monitor patients with hepatic impairment for QTc prolongation and other cardiovascular adverse reactions. The potential risks and benefits of anagrelide therapy in a patient with mild and moderate hepatic impairment should be assessed before treatment is commenced. Reduce anagrelide dose in patients with moderate hepatic impairment. Avoid use of anagrelide in patients with severe hepatic impairment. In patients with heart failure, bradyarrhythmias, or electrolyte abnormalities, consider periodic monitoring with electrocardiograms [see Clinical Pharmacology ( 12.2 )] . Anagrelide is a phosphodiesterase 3 (PDE3) inhibitor and may cause vasodilation, tachycardia, palpitations, and congestive heart failure. Other drugs that inhibit PDE3 have caused decreased survival when compared with placebo in patients with Class III-IV congestive heart failure [see Drug Interactions ( 7.2 )] . In patients with cardiac disease, use anagrelide only when the benefits outweigh the risks. 5.2 Pulmonary Hypertension Cases of pulmonary hypertension have been reported in patients treated with anagrelide. Evaluate patients for signs and symptoms of underlying cardiopulmonary disease prior to initiating and during anagrelide therapy [see Adverse Reactions ( 6.1 )] . 5.3 Bleeding Risk Use of concomitant anagrelide and aspirin increased major hemorrhagic events in a postmarketing study. Assess the potential risks and benefits for concomitant use of anagrelide with aspirin, since bleeding risks may be increased. Monitor patients for bleeding, including those receiving concomitant therapy with other drugs known to cause bleeding (e.g., anticoagulants, PDE3 inhibitors, NSAIDs, antiplatelet agents, selective serotonin reuptake inhibitors) [see Drug Interactions ( 7.3 ), Clinical Pharmacology ( 12.3 )] . 5.4 Pulmonary Toxicity Interstitial lung diseases (including allergic alveolitis, eosinophilic pneumonia and interstitial pneumonitis) have been reported to be associated with the use of anagrelide in post-marketing reports. Most cases presented with progressive dyspnea with lung infiltrations. The time of onset ranged from 1 week to several years after initiating anagrelide. If suspected, discontinue anagrelide and evaluate. Symptoms may improve after discontinuation [see Adverse Reactions ( 6 )].