Analysis of the adverse events in a population consisting of 942 patients diagnosed with myeloproliferative diseases of varying etiology (ET: 551; PV: 117; OMPD: 274) has shown that all disease groups have the same adverse event profile. While most reported adverse events during anagrelide therapy have been mild in intensity and have decreased in frequency with continued therapy, serious adverse events were reported in these patients. These include the following: Congestive heart failure, myocardial infarction, cardiomyopathy, cardiomegaly, complete heart block, atrial fibrillation, cerebrovascular accident, pericarditis, pulmonary infiltrates, pulmonary fibrosis, pulmonary hypertension, pancreatitis, gastric/duodenal ulceration and seizure.
Of the 942 patients treated with anagrelide for a mean duration of approximately 65 weeks, 161 (17%) were discontinued from the study because of adverse events or abnormal laboratory test results. The most common adverse events for treatment discontinuation were headache, diarrhea, edema, palpitation and abdominal pain. Overall, the occurrence rate of all adverse events was 17.9/1000 treatment days. The occurrence rate of adverse events increased at higher dosages of anagrelide.
The most frequently reported adverse reactions to anagrelide (in ≥5% of 942 patients with myeloproliferative disease) in clinical trials were: Headache 43.5%, palpitations 26.1%, diarrhea 25.7%, asthenia 23.1%, edema 20.6%, nausea 17.1%, abdominal pain 16.4%, dizziness 15.4%, pain 15%, dyspnea 11.9%, flatulence 10.2%, vomiting 9.7%, fever 8.9%, peripheral edema 8.5%, rash including urticarcia 8.3%, chest pain 7.8%, anorexia 7.7%, tachycardia 7.5%, pharyngitis 6.8%, malaise 6.4%, cough 6.3%, paresthesia 5.9%, back pain 5.9%, pruritis 5.5% and dyspepsia 5.2%.
Adverse events with an incidence of 1% to <5% included:
Body as a Whole: Flu symptoms, chills, photosensitivity.
Cardiovascular System: Arrhythmia, hemorrhage, cardiovascular disease, angina pectoris, heart failure, postural hypotension, thrombosis, vasodilatation, migraine, syncope.
Digestive System: Constipation, GI distress, GI hemorrhage, gastritis, melena, aphthous stomatitis, eructation.
Hemic & Lymphatic System: Anemia, thrombocytopenia, ecchymosis, lymphadenopathy. Platelet count <100,000/microliter occurred in 84 patients (ET: 35; PV: 9; OMPD: 40), reduction <50,000/microliter occurred in 44 patients (ET: 7; PV: 6; OMPD: 31) while on anagrelide therapy. Thrombocytopenia promptly recovered upon discontinuation of anagrelide.
Hepatic System: Elevated liver enzymes were observed in 3 patients (ET: 2; OMPD: 1) during anagrelide therapy.
Musculoskeletal System: Arthralgia, myalgia, leg cramps.
Nervous System: Depression, somnolence, confusion, insomnia, hypertension, nervousness, amnesia.
Nutritional Disorders: Dehydration.
Respiratory System: Rhinitis, epistaxis, respiratory disease, sinusitis, pneumonia, bronchitis, asthma.
Skin and Appendages: Skin disease, alopecia.
Special Senses: Amblyopia, abnormal vision, tinnitus, visual field abnormality, diplopia.
Urogenital System: Dysuria, hematuria.
Renal abnormalities occurred in 15 patients (ET: 10; PV: 4; OMPD: 1). Six ET, 4 PV and 1 with OMPD experienced renal failure (approximately 1%) while on anagrelide treatment; in 4 cases, the renal failure was considered to be possibly related to anagrelide treatment. The remaining 11 were found to have preexisting renal impairment. Doses ranged from 1.5-6 mg/day, with exposure periods of 2-12 months. No dose adjustment was required because of renal insufficiency.
The adverse event profile for patients in clinical trials on anagrelide therapy (in ≥5% of 942 patients with myeloproliferative diseases) is shown in the following bar graph: (See diagram.)
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